FEMA – 253, 2nd Edition, October 1995 

FEDERAL EMERGENCY MANAGEMENT AGENCY 

AMERICAN GEOPHYSICAL UNION 
SEISMIC SLEUTHS 

A Teacher’s Package for Grades 7-12 

Produced by 

The American Geophysical Union 

2000 Florida Avenue, N.W. 

Washington, DC 20009 

Supported by the 

Federal Emergency Management Agency 

Washington, DC 20472

This product was developed by the American Geophysical Union (AGU) with financial 

support from the Federal Emergency Management Agency (FEMA) under Cooperative 

Agreement EMW-92-K-3892. AGU is solely responsible for the accuracy of statements and 

interpretations contained herein. 

Funding for this publication was allocated to FEMA by The United States Congress, under 

the Earthquake Hazards Reduction Act of 1977, as amended. FEMA maintains a royaltyfree, nonexclusive and irrevocable right to reproduce, publish or otherwise use and to 

authorize others to use, the work for public education purposes. FEMA hereby authorizes 

and encourages the educational community to reproduce this product in its entirety and to 

disseminate it at no cost to the recipient. 

Single copies of this publication may be obtained from FEMA at no cost by contacting the 

FEMA Warehouse - 

Toll free number: 1-800-480-2520 ♦ Fax: 301-497-6378 

Mailing address: P.O. Box 2012, Jessup, MD 20794-2012. 

AGU / FEMA i S EISMIC S LEUTHS

AGU / FEMA iii S EISMIC S LEUTHS

AGU/FEMA EARTHQUAKE CURRICULUM 

Project Director:

M. Frank Watt Ireton, Manager of Pre-college Education, American 

 Geophysical Union 

Associate Project Director:

Karen Lee Spaulding, Manager of Professional and Continuing 

 Education, American Geophysical Union 

Project Editor:

Mary Liston Liepold, Washington, District of Columbia 

Copy Editor:

Pam Knox, Senior Copy Editor, American Geophysical Union 

Authors and Reviewers:

Roy Q. Beven, Science Teacher, San Juan Capistrano, California 

Jane Nelson Crowder, Science Teacher, Bellevue, Washington 

Jo Ellen Dodds, Science Teacher, Twin Falls, Idaho 

Lynda Vance, Science Teacher, Boise, Idaho 

James F. Marran, Social Studies Teacher, Wilmette, Illinois 

Ronald H. Morse, Science Teacher, Cicero, New York 

Walter L. Sharp, Science Teacher, Camillus, New York 

James D. Sproull, Science Teaching Consultant, Kirkland, 

 Washington 

Consultants and Reviewers:

Charles Ault, Science Educator, Lewis and Clark College, Portland, 

 Oregon 

Robert A. Christman, Geologist and Science Educator, Western 

 Washington University, Bellingham, Washington 

Henry J. Lagorio, Architectural Engineer, Orinda, California 

Sue J. Nava, Seismologist, University of Utah, Salt Lake City, Utah 

Martin Stout, Engineering Geologist, Whittier, California 

Keith A. Sverdrup, Seismologist, University of Wisconsin, Milwaukee, 

 Wisconsin 

Diana Todd, Structural Engineer, National Institute of Science and 

 Technology, Gaithersburg, Maryland 

Monte D. Wilson, Geologist, Boise State University, Boise, Idaho 

Design by:

Auras Design, Washington, District of Columbia 

Illustrators:

Susie Duckworth, Falls Church, Virginia 

Max Karl Winkler, Silver Spring, Maryland 

Graphic Artist:

Gregg Sekscienski, Albuquerque, New Mexico 

Project Officer:

Marilyn P. MacCabe, Mitigation Directorate, Federal Emergency 

 Management Agency 
AGU / FEMA iv S EISMIC S LEUTHS

ACKNOWLEDGMENTS 

The American Geophysical Union (AGU) and the Federal Emergency 

Management Agency (FEMA) acknowledge with gratitude the many 

individuals who provided technical experience, teaching knowledge, and 

classrooms for field testing in the development of this project. Along 

with the authors and consultants, they provided continuous feedback in 

the development of these materials. Without the assistance of these 

individuals and the students who participated in the field test this volume 

would not have been possible. 

Technical Reviewers:

William Chavez, Geological Engineer, New Mexico Institute of 

 Mining and Technology, Socorro, New Mexico 

Lucy Jones, Seismologist, United States Geological Survey 

David Love, Environmental Geologist, New Mexico Bureau of Mines 

 and Mineral Resources, Socorro, New Mexico 

Mary Ellen Williams, Earthquake Program Specialist, United States 

 Geological Survey, Woods Hole, Massachusetts 

Curriculum Reviewers:

Allen Bone, Science Teacher, Butte, Montana 

William Krayer, Science Teacher, Gaithersburg, Maryland 

Sharon Stroud, Science Teacher, Colorado Springs, Colorado 

Field Test Teachers: 

Roger Alsup, Jim Anderson, Richard Arrington, Joann Ball, Allen Bone, 

Gail Chaid, Linda Dudley, Jo Dodds, Elizabeth Ellis, George Foley, John 

Gallagher, Melody Green, Paul Grogger, Kay Kidder, Paul Jamerson, 

Larry Madden, Lloyd Magnuson, Gay Ann Masolo, Sue Ayn Moore, 

Becky Orahood, Doyle Orrell, Nancy Sallee, Sandy Shutey, Jack Staker, 

Ann Sullivan, Edith Thurman, Maris Ward, Leslie Wehner, Ronald 

Wieland, and Walt Woolbaugh. 

Teachers who participated in the two 1994 Seismic Sleuths Leadership 

Institutes also conducted field testing and review of the lessons during 

the institutes. The suggestions and additions by the initial field test and 

institute teacher participants have contributed to a stronger curriculum 

package. 

A special note of thanks to Katharyn E. K. Ross, whose comprehensive 

Fourth Edition of Earthquake Education Materials for Grades K - 12 

contributed greatly to the unit resource lists in this package, and to Sean 

Cox, teacher, Salem High School, New Hampshire, who provided the 

appendix to Unit Six. 
AGU / FEMA v S EISMIC S LEUTHS
INTRODUCTION 

Earthquakes are mystifying events. They are as 

unpredictable as they are powerful, and not even 

seismologists fully understand the forces within the Earth 

that set them in motion. As an educator, you can capitalize 

on that mysterious appeal to engage your students’ interest. 

Ultimately, however, the purpose of these lessons is to 

demystify earthquakes, and to counter the fatalism that 

frequently accompanies ignorance about natural 

phenomena. Interactive lessons invite students to discover 

what is known about quakes—the considerable body of 

knowledge that deals with their causes, the patterns of their 

occurrence, and what human beings can do to minimize 

their catastrophic effects on themselves and their 

communities. 

The units in this package follow a pattern of zooming in and 

out, beginning with concerns closest to home, moving to 

general principles and global perspectives, then homing in 

again to engage students in evaluating their personal 

preparedness and that of their families, schools, 

neighborhoods, and communities. Look for the magnifying 

glass symbols opposite the text, which indicate essential 

vocabulary and helpful hints (Teaching Clues and Cues). 

Units 1 and 6 deal most specifically with the personal and 

local, but every unit contains a mixture of general 

information and specific, local applications. A healthy 

respect for the power of earthquakes requires both kinds of 

understanding. Units 4 and 5 feature interactive lessons in 

architecture and engineering, topics seldom dealt with in 

grade 7-12 curriculum materials. 

You may not find time to teach every lesson in this package. 

For teachers who must pick and choose, most of the lessons 

are designed to stand on their own. Take time to familiarize 

yourself with the outline, however. Read the unit 

introductions; take advantage of the background readings 

provided and of the unit resource lists. The Teacher 

Preparation section in each lesson outlines things you need 

to do before class begins, in addition to assembling the 

items on the materials list. Plan ahead now for the 

cooperation you will need in Unit 1, the 

materials you will need in Unit 4, and the field trips you will 

make in Unit 5. You’ll see a burst of learning to reward 

your efforts and a wealth of ideas to enrich your science and 

social studies teaching. 

Theory takes a back seat to hands-on experience in most of 

these lessons. As its name implies, this Seismic Sleuths 

package focuses on discovery. Ideally, the process of 

discovery will ripple through the town or city outside your 

classroom. Beginning in Unit 1, students will be interacting 

with a wide range of public officials. Please initiate and 

encourage these relationships. They will benefit the 

students, the school, and the community. 

Through interacting with adults in positions of 

responsibility, students will develop a realistic sense of how 

their community functions day to day and how it would 

function in the aftermath of an earthquake or other natural 

disaster. Most will find it enormously reassuring to learn 

that emergency plans are in effect. Moreover, they will be 

empowered by the knowledge that their individual and 

collective actions can make a difference. Cultivating 

relationships within their community will also expose 

students to a variety of careers they might never have 

considered and provide a motivation to stay in school. In the 

long range, these activities will prepare today’s students to 

be tomorrow’s concerned and informed participants in 

democracy. 

The school will benefit from these relationships by 

widening the pool of local adults who take an active interest 

in education, share their expertise and experience, and serve 

as role models for students. The community at large will 

benefit greatly, whether or not it is in an area known to be 

seismically active. Most of the kinds of emergency planning 

that students will learn about, and model in Unit 6, would be 

appropriate not only in the event of an earth- quake but also 

in case of flood, hurricane, or other large-scale disaster. In 

just the last few years, almost every section of the country 

has experienced destructive natural events. 

AGU / FEMA vi S EISMIC S LEUTHS
OVERVIEW OF THE UNITS 

Unit 1. This three-part introductory unit sets the stage for 

what follows. Every teacher should take time to include 

some of the materials contained in this unit. The 

introductory lesson assesses students’ knowledge of 

earthquakes. In lesson two students describe their own 

experiences and tell how they would prepare for an 

earthquake. Lesson three requires students to make contact 

with emergency personnel in their community to ascertain 

emergency preparedness plans. Lessons in this unit are 

referred to in future units. 

Unit 2. This five-part unit moves students beyond their 

personal survival into the causes of earthquakes. This unit 

sketches the big picture, building on students’ knowledge 

from earth science or other science classes. The unit begins 

with students modeling stress buildup in the crust, 

followed by lessons on how earthquakes and other 

evidence tell scientists about the structure of the Earth. In 

the third lesson, students contrast historic time with the 

vastness of geologic time and simulate techniques of 

paleoseismology. The unit concludes with lessons on some 

potential side effects of earthquakes, such as tsunami, 

liquefaction, and landslides. Students study how the 

geology of an area influences the destructive effects and 

how high population density at unsafe sites can increase 

the amount of damage during an earthquake. 

Unit 3. In this four-part unit, students learn about the 

different wave motions during an earthquake and how 

these motions are studied. A historical piece on the 

development of seismology adds background to students’ 

knowledge. Students study and simulate the measurement 

of earthquakes using the Richter and Mercalli scales to find 

out how seismologists arrive at earthquake measurements. 

This unit concludes with activities that plot the distribution 

of earthquakes worldwide, then focuses in on local 

earthquakes, first in Japan, then in the United States. It 

offers a variety of lessons in science, mathematics, and 

social studies. 

Unit 4. This five-part unit is designed to allow students to 

construct an understanding of how buildings respond to 

earthquakes. Lessons on building design and how 

earthquake forces act on various designs provide students 

with information on how to build earthquake resistant 

structures. Students then apply this knowledge by 

constructing testing devices and testing their designs. This 

unit is critical for developing students’ understanding of 

why buildings collapse and what can be done to make 

buildings safer. 

Unit 5. This five-part unit focuses students’ attention on 

what to do before, during, and after an earthquake. By 

studying historical earthquakes as reported in the press, 

students learn how people have responded to earthquakes in 

the past. Students then learn what their response should be 

during an earthquake by planning and practicing earthquake 

drills. Students conduct safety assessments of their home, 

classroom, and community and see how secondary disasters 

associated with earthquakes can also be alleviated. 

Unit 6. This concluding four-part unit offers a variety of 

summing-up and assessment activities. Writing activities, a 

fast paced quiz game, and a high pressure simulation allow 

students a chance to show off what they have learned in this 

curriculum. An extensive resource list provides detailed 

instructions for conducting a community-wide disaster 

simulation that becomes realistic and dramatic with the 

involvement of community disaster officials. 

AGU / FEMA vii S EISMIC S LEUTHS
SEISMIC SLEUTHS MATRICES 

FOR THE NATIONAL SCIENCE EDUCATION STANDARDS 

A Seismic Sleuths development team has put together the 

matrices on the following pages to use in correlating the 

Seismic Sleuths materials with the National Science Education 

Standards. The National Science Education Standards, under 

development by the National Research Council since 1993, 

will be released in late 1995. The Standards have been 

developed through consensus building among K-12 teachers, 

teacher education faculty, scientists, and other education 

specialists. Through this process a document that represents 

the broad thinking of the science education community is 

being developed as to what students should know, how they 

should be taught, and how they should be assessed. The 

Standards are meant to be descriptive rather than prescriptive 

and designed to be a tool to strengthen science education. 

Using the Seismic Sleuths Standards matrices 

The development team, working with the November 1994 

draft of the National Science Education Standards, examined 

Seismic Sleuths section by section identifying correlations to 

the Science Content areas listed in the Standards. Two criteria 

were used: the section made a strong and direct connection to 

that content area, or the section made an indirect connection. 

A strong, direct connection is shown in bold faced type. 

The following matrices are provided. Below is a summary of 

Seismic Sleuths and the content areas listed in the Standards. 

This page shows at a glance the correlations between Seismic 

Sleuths and the Standards. The next six pages describe more 

detailed correlations between Seismic Sleuths and the 

Standards using wording from the Standards. In some cases 

the development team felt that where a particular concept was 

not listed in the wording of the Standards a possible 

connection could be shown in parentheses. 

When using the matrices it should be kept in mind the 

descriptive nature of the Standards. The connections shown in 

these matrices are suggested connections based on the 

development team’s experience working with Seismic Sleuths. 

Many other correlations can be made and will become evident 

as the curriculum materials are used. Additionally, 

connections can also be made between Seismic Sleuths and 

Benchmarks for Science Literacy, (AAAS, 1993), Content 

Core, (NSTA, 1992), and Earth Science Content Guidelines 

Grades K-12, (AGI, 1991). The user is referred to these 

documents for further connections. 

SEISMIC 

SLEUTHS 

SECTIONS 

SCIENCE 

AS INQUIRY 

PHYSICAL 

SCIENCE 

EARTH AND 

SPACE SCIENCE 

SCIENCE AND 

TECHNOLOGY 

SCIENCE IN 

PERSONAL AND 

SOCIAL PERSPECTIVES 

HISTORY AND 

NATURE OF 

SCIENCE 

UNIFYING 

CONCEPTS AND 

PROCESSES 

1.1 g    g  

1.2   g 

1.3  g

2.1 g g   

2.2   g    

2.3   g   

2.4  g g g  

2.5    g 

3.1 g g  g  

3.2 g  g g g g g

3.3 g g g g g g 

3.4 g g  g

4.1  g g g g

4.2 g g g g  

4.3 g g g g g g

4.4 g g g   g

4.5 g g g g  g

5.1 g g g g 

5.2  g g

5.3  g g

5.4  g g

5.5  g g

6.1  g g g

6.2  g g

6.3 g 

6.4 g   g g g

gDirect connection  Indirect connection

AGU / FEMA viii S EISMIC S LEUTHS
SEISMIC SLEUTHS MATRICES 

FOR THE NATIONAL SCIENCE EDUCATION STANDARDS 

UNIT 1: What’s It All About? Pre-assessment of student’s knowledge of earthquakes and hazards preparedness. 

SEISMIC 

SLEUTHS 

SECTIONS 

SCIENCE 

AS INQUIRY 

PHYSICAL 

SCIENCE 

EARTH AND 

SPACE SCIENCE 

SCIENCE AND 

TECHNOLOGY 

SCIENCE IN 

PERSONAL AND 

SOCIAL 

PERSPECTIVES 

HISTORY AND 

NATURE OF 

SCIENCE 

UNIFYING 

CONCEPTS AND 

PROCESSES 

1.1 What Do You 

Know About 

Earthquakes? 

Students explore 

their 

conceptions of 

earthquakes by 

writing about a 

hypothetical 

earthquake as 

seen through the 

eyes of a 

reporter, a 

scientist, and a 

member of the 

general public. 

Abilities related 

to scientific 

inquiry 

Understanding 

about scientific 

inquiry 

Motions and 

forces 

Structure of the 

Earth system 

Energy in the 

Earth system 

Abilities of 

technological 

design 

Personal and 

community health 

Natural and humaninduced hazards

Risks and benefits 

Science and 

technology in local, 

national, and global 

challenges

Science as a 

human endeavor 

Nature of 

scientific 

knowledge 

Evidence, 

models, and 

explanation 

Change, 

constancy, and 

measurement 

1.2 It Could 

Happen Here 

Students 

consider their 

needs in an 

emergency and 

their preparation 

for an 

emergency. 

Motions and 

forces 

Understanding 

about science 

and technology 

Personal and 

community health 

Natural and humaninduced hazards 

Risks and benefits 

Order and 

organization 

1.3 Investigating 

Community 

Preparedness 

Students 

investigate their 

community’s 

preparedness. 

Abilities of 

technological 

design 

Personal and 

community health 

Natural and humaninduced hazards 

Risks and benefits 

AGU / FEMA ix S EISMIC S LEUTHS
SEISMIC SLEUTHS MATRICES 

FOR THE NATIONAL SCIENCE EDUCATION STANDARDS 

UNIT 2: What Happens When The Earth Quakes? An exploration of earthquake processes, including causes and 

measurement. 

SEISMIC 

SLEUTHS 

SECTIONS 

SCIENCE 

AS INQUIRY 

PHYSICAL 

SCIENCE 

EARTH AND 

SPACE 

SCIENCE 

SCIENCE AND 

TECHNOLOGY 

SCIENCE IN 

PERSONAL AND 

SOCIAL 

PERSPECTIVES 

HISTORY AND 

NATURE OF 

SCIENCE 

UNIFYING 

CONCEPTS 

AND 

PROCESSES 

2.1 Stick-Slip 

Movement 

Students model 

movement 

along a fault. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about 

scientific 

inquiry 

Motions and 

forces 

(friction and 

energy) 

Energy in the 

Earth system 

(Dynamic 

crust) 

Natural hazards Evidence, 

models, and 

explanation 

2.2 Shifting 

Plates and 

Wandering 

Poles 

A three-part 

exploration 

about how 

scientists 

determine if the 

Earth’s crust is in 

motion. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about scientific 

inquiry 

Properties & 

changes in 

matter

(magnetism)

Motions and 

Forces

Structure of 

the Earth 

system 

Energy in the 

Earth system 

Origin and 

evolution of 

the Earth 

system

Understanding 

about science 

and 

technology 

Natural hazards Nature of 

scientific 

knowledge 

Evidence, 

models, and 

explanation 

2.3 Earthquake 

in Geologic 

Time 

Students explore 

long time 

intervals and 

use models to 

study 

earthquakes in 

the past.. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about scientific 

inquiry 

Motions and 

forces 

Earth’s 

history 

Origin and 

evolution of 

the Earth 

system

Natural hazards Historical 

perspectives 

Evidence,

models, and 

explanation, 

maps

2.4 Earthquake 

Hazards 

Students use 

models, 

research, and 

mathematics to 

study 

earthquake 

hazards. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about scientific 

inquiry

Forces and 

motion 

(gravity, 

waves, and 

energy) 

Interactions 

of energy and 

matter

Energy in the 

Earth system 

Natural hazards Historical 

perspectives 

Evidence, 

models, and 

explanation 

Change, 

constancy, 

and 

measurement

2.5 Quake-Smart 

Siting 

Students 

interpret soil and 

earthquake 

related maps. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about scientific 

inquiry

Structure of 

the Earth 

system 

Abilities of 

technological 

design 

Natural hazards Evidence, 

models, and 

explanation, 

maps 

AGU / FEMA x S EISMIC S LEUTHS
SEISMIC SLEUTHS MATRICES 

FOR THE NATIONAL SCIENCE EDUCATION STANDARDS 

UNIT 3: How Do People Learn About Earthquakes? Students explore the science and history of seismology. 

SEISMIC 

SLEUTHS 

SECTIONS 

SCIENCE 

AS INQUIRY 

PHYSICAL 

SCIENCE 

EARTH AND 

SPACE 

SCIENCE 

SCIENCE AND 

TECHNOLOGY 

SCIENCE IN 

PERSONAL AND 

SOCIAL 

PERSPECTIVES 

HISTORY AND 

NATURE OF 

SCIENCE 

UNIFYING 

CONCEPTS 

AND 

PROCESSES 

3.1 The Waves 

of Quakes 

Students explore 

waves and 

discover how 

waves transfer 

energy. During 

this exploration, 

students 

connect this 

understanding to 

primary and 

secondary 

waves. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about 

scientific 

inquiry

Motions and 

forces 

Interactions 

of energy and 

matter

Structure of 

the Earth 

system 

Natural and humaninduced hazards Change, 

constancy, 

and 

measurement 

3.2 Pioneering 

Ideas 

Students explore 

the early work of 

three scientists. 

Understanding 

about 

scientific 

inquiry 

Forces and 

motions 

Interactions of 

energy and 

matter

Energy in the 

Earth system 

Origin and 

evolution of 

the Earth 

system

Understanding 

about science 

and 

technology 

Science as a 

human 

endeavor 

Nature of 

scientific 

knowledge 

Historical 

perspectives

Evidence, 

models, and 

explanation 

3.3 Sizing Up 

Earthquakes: 

The Mercalli 

Scale, Calling 

Station KWAT 

In this simulation 

of a radio talk 

show after an 

earthquake, 

students learn 

how 

seismologists 

establish 

earthquake 

intensity based 

upon damage 

people observe 

and report. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about 

scientific 

inquiry

Motions and 

forces 

Interactions of 

energy and 

matter 

Energy in the 

Earth system 

Abilities of 

technological 

design 

Natural and 

human-induced 

hazards 

Science as a 

human 

endeavor 

Nature of 

scientific 

knowledge

Change, 

constancy, 

and 

measurement 

3.4 Distribution 

of Earthquakes 

Three activities 

on plotting the 

locations of 

earthquakes on 

map and 

making a 3-D 

model. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about scientific 

inquiry

Structure of 

the Earth 

system 

Energy in the 

Earth system

Natural hazards 

Risks and benefits 

Historical 

perspectives 

Evidence,

models, and 

explanation 

AGU / FEMA xi S EISMIC S LEUTHS
SEISMIC SLEUTHS MATRICES 

FOR THE NATIONAL SCIENCE EDUCATION STANDARDS 

UNIT 4: Can Buildings Be Made Safer? Students construct an understanding of how ground shaking during an 

earthquake can damage buildings and how buildings can be made better able to withstand this shaking. 

SEISMIC 

SLEUTHS 

SECTIONS 

SCIENCE 

AS INQUIRY 

PHYSICAL 

SCIENCE 

EARTH AND 

SPACE 

SCIENCE 

SCIENCE AND 

TECHNOLOGY 

SCIENCE IN 

PERSONAL AND 

SOCIAL 

PERSPECTIVES 

HISTORY AND 

NATURE OF 

SCIENCE 

UNIFYING 

CONCEPTS 

AND 

PROCESSES 

4.1 Building Fun 

Students investigate 

the physical properties 

of building materials 

and design while 

considering how these 

might affect the way a 

structure withstands 

forces. 

Abilities 

related to 

scientific 

inquiry 

Properties & 

changes in 

matter 

(physical) 

Motions and 

Forces 

Abilities of 

technological 

design 

Natural and 

human-induced 

hazards 

Evidence, 

models, and 

exploration 

4.2 Structural 

Reinforcement: The 

Better Building 

Students learn how 

additional structural 

elements strengthen a 

structure to carry forces 

resulting from 

earthquake shaking. 

Understanding 

about 

scientific 

inquiry 

Forces and 

motions 

Abilities of 

technological 

design 

Understanding 

about science 

and 

technology

Natural and 

human-induced 

hazards 

Nature of 

scientific 

knowledge 

Evidence, 

models, and 

explanation 

4.3 The BOSS Model: 

Building Oscillation 

Seismic Simulation 

Students investigate 

how energy enters a 

structure and discover 

the phenomenon of 

resonance. They 

measure the natural 

frequencies of the 

different height rod 

assemblies of the 

BOSS Models and 

correlate these motions 

to those of buildings 

and earthquakes. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about 

scientific 

inquiry

Forces and 

motions 

Interactions 

of energy 

and matter

Understanding 

about science 

and 

technology 

Natural and 

human-induced 

hazards 

Nature of 

scientific 

knowledge 

Evidence, 

models, and 

explanation 

4.4 Earthquake in a 

Box 

In cooperative groups, 

students construct an 

inexpensive shake 

table for testing 

structures they have 

built. 

Understanding 

about 

scientific 

inquiry 

Forces and 

motions 

Interactions 

of energy 

and matter

Abilities of 

technological 

design 

Understanding 

about science 

and 

technology

Natural and humaninduced hazards Nature of 

science 

Evidence, 

models, and 

explanations 

4.5 The Building 

Challenge 

Students design and 

construct a structure 

then test it for the ability 

to withstand forces that 

could be encountered 

in an earthquake. This 

can be used s a 

performance 

assessment of the 

entire unit. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about 

scientific 

inquiry 

Properties & 

changes in 

matter 

(physical) 

Forces and 

motions 

Interactions 

of energy 

and matter

Abilities of 

technological 

design 

Understanding 

about science 

and 

technology

Natural and 

human-induced 

hazards 

Science as a 

human 

endeavor 

Evidence, 

models, and 

explanations 

AGU / FEMA xii S EISMIC S LEUTHS
SEISMIC SLEUTHS MATRICES 

FOR THE NATIONAL SCIENCE EDUCATION STANDARDS 

UNIT 5: What Should People Do Before, During, and After An Earthquake? 

SEISMIC 

SLEUTHS 

SECTIONS 

SCIENCE 

AS INQUIRY 

PHYSICAL 

SCIENCE 

EARTH AND 

SPACE 

SCIENCE 

SCIENCE AND 

TECHNOLOGY 

SCIENCE IN 

PERSONAL AND 

SOCIAL 

PERSPECTIVES 

HISTORY AND 

NATURE OF 

SCIENCE 

UNIFYING 

CONCEPTS 

AND 

PROCESSES 

5.1 Predicting 

Earthquakes 

Students explore 

the tantalizing 

possibilities of 

earthquake 

prediction. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about scientific 

inquiry 

Understanding 

about science 

and technology 

Personal and 

community health 

Natural hazards 

Nature of 

science 

Historical 

perspectives 

Evidence, 

models, and 

exploration 

5.2 Starting 

Here, Starting 

Now 

Students learn 

how to react in 

the event of an 

earthquake. 

Motions and 

Forces 

Understanding 

about science 

and technology 

Natural hazards 

5.3 Find and Fix 

the Hazards 

Students study 

home 

construction and 

retrofitting 

techniques. 

Motions and 

Forces 

Understanding 

about science 

and technology 

Natural hazards 

5.4 Rapid Visual 

Screening in 

the Community 

Students 

evaluate the 

potential 

earthquake 

damage to 

various 

structures in their 

community. 

Motions and 

Forces 

Understanding 

about science 

and technology 

Personal and 

community health 

Natural hazards

5.5 Are the 

Lifelines 

Open? 

Students assess 

their 

community’s 

vulnerability to 

earthquake 

damage. 

Motions and 

Forces 

Understanding 

about science 

and technology 

Personal and 

community health 

Natural hazards

AGU / FEMA xiii S EISMIC S LEUTHS
SEISMIC SLEUTHS MATRICES 

FOR THE NATIONAL SCIENCE EDUCATION STANDARDS 

UNIT 6: Now You Know It, Can You Show It? A variety of summing-up and assessment activities that showcase 

students’ knowledge. 

SEISMIC 

SLEUTHS 

SECTIONS 

SCIENCE 

AS INQUIRY 

PHYSICAL 

SCIENCE 

EARTH AND 

SPACE 

SCIENCE 

SCIENCE AND 

TECHNOLOGY 

SCIENCE IN 

PERSONAL AND 

SOCIAL 

PERSPECTIVES 

HISTORY AND 

NATURE OF 

SCIENCE 

UNIFYING 

CONCEPTS 

AND 

PROCESSES 

6.1 Preparing 

for the Worst 

Students 

assume the 

roles of 

emergency 

planning officials 

in a hypothetical 

community. 

Forces and 

motions 

Abilities of 

technological 

design 

Understanding 

about science 

and technology

Personal and 

community health 

Natural and humaninduced hazards

Order and 

organization 

Evidence, 

models, and 

explanation 

6.2 Earthquakes 

Simulation: 

Putting Plans 

into Action 

An emergency 

simulation 

exercise. 

Motions and 

forces 

Understanding 

about science 

and technology 

Personal and 

community health 

Natural and 

human-induced 

hazards 

Science and 

technology in local, 

national, and global 

challenges

6.3 What’s Your 

E.Q., I.Q.? 

A quiz show 

format for 

assessment. 

Nature of 

scientific 

knowledge 

Evidence, 

models, and 

explanation 

6.4 Hey, Look at 

Me Now! 

An assessment 

activity that 

repeats the 

writing exercise 

in 1.1. 

Abilities 

related to 

scientific 

inquiry 

Understanding 

about scientific 

inquiry 

Motions and 

forces 

Structure of 

the Earth 

system 

Energy in the 

Earth system 

Origin and 

evolution of 

the Earth 

system 

Understanding 

about science 

and technology 

Personal and 

community health 

Natural and 

human-induced 

hazards 

Science and 

technology in a 

local, national, 

and global 

challenges

Evidence, 

models, and 

explanation 

AGU / FEMA xiv S EISMIC S LEUTHS
TABLE OF CONTENTS 

SEISMIC SLEUTHS CURRICULUM PACKAGE 

Unit 1. What’s It All About? .............................................................2 

1. What Do You Know about Earthquakes?.........................................3 

2. It Could Happen Here.....................................................................11 

3. Investigating Community Preparedness .........................................17 

Unit Resources ...................................................................................25 

Unit 2. What Happens When the Earth Quakes? .........................38 

1. Stick-Slip Movement......................................................................39 

2. Shifting Plates and Wandering Poles..............................................45 

3. Earthquakes in Geologic Time .......................................................67 

4. Earthquake Hazards........................................................................89 

5. Quake-Smart Siting ......................................................................127 

Unit Resources .................................................................................137 

Unit 3. How Do People Learn about Earthquakes? ....................142 

1. The Waves of Quakes...................................................................143 

2. Pioneering Ideas ...........................................................................151 

3. Sizing Up Earthquakes .................................................................161 

4. Distribution of Earthquakes..........................................................193 

Unit Resources .................................................................................221 

Unit 4. Can Buildings Be Made Safer?.........................................226 

1. Building Fun.................................................................................227 

2. Structural Reinforcement: The Better Building............................232 

3. The BOSS Model: Building Oscillation Seismic Simulation.......247 

4. Earthquake in a Box .....................................................................257 

5. The Building Challenge................................................................263 

Unit Resources .................................................................................270 

Unit 5. What Should People Do Before, During, 

and After an Earthquake?.............................................................272 

1. Predicting Earthquakes.................................................................273 

2. Starting Here, Starting Now .........................................................289 

3. Find and Fix the Hazards (Wood Frame Homes).........................299 

4. Rapid Visual Screening (RVS) in the Community.......................311 

5. Are the Lifelines Open? Critical Emergency 

Facilities and Lifeline Utility Systems .........................................319 

Unit Resources .................................................................................327 

Unit 6. Now You Know It, Can You Show It? .............................330 

1. Preparing for the Worst: A Simulation.........................................331 

2. Earthquake Simulation: Putting Plans into Action .......................341 

3. What’s Your E.Q. I.Q.? ................................................................345 

4. Hey, Look at Me Now!.................................................................353 

Unit Resources .................................................................................355 

Appendix: Earthquake Drill..........................................................356 

Earthquake Glossary .....................................................................360 

AGU / FEMA xv S EISMIC S LEUTHS
AGU / FEMA xvi S EISMIC S LEUTHS
UNIT ONE 
INTRODUCTION

What’s It All About? 

AGU / FEMA 2 S EISMIC S LEUTHS

1 

Every teacher, no matter how busy, should take time 

to cover some of the material in this three-part 

introductory unit. Through brainstorming and new 

contacts within the community, students move from 

planning for their own safety to learning firsthand 

about critical facilities and lifeline systems that serve 

large numbers of people. 

Please read through all the lessons well in advance, 

especially noting the Teacher Preparation section at 

the beginning of each Procedure. In this unit you will 

build a foundation for the units and lessons ahead by 

enlisting the cooperation of your school’s 

administrators, your fellow teachers, and emergency 

personnel throughout the community and even 

beyond. Take time to scan the rest of the units too. 

You may want to let parents know now that you will 

be asking for their help in the Unit Five field trips and 

home safety activities. If you plan to involve the 

school community and outside experts in the 

culmination of Unit Four, also include this information 

in the initial contacts you make during this unit. 

Lesson one, which students may complete either 

individually or in small groups, provides an 

assessment of what students already know about 

earthquakes plus experience with both scientific and 

popular ways of describing them. The worksheets 

provided will make this activity easier for students 

who aren’t thoroughly comfortable with writing. In 

lesson two, students distinguish between luxuries and 

necessities, describe their own experience with natural 

hazards and how they and their families obtained the 

necessities, and come to see how preparedness can 

help individuals and families cope effectively in the 

event of an earthquake or other natural disaster. In the 

following units, students will learn some strategies for 

risk reduction. 

Lesson three, which requires the cooperation of a 

number of emergency personnel in the community at 

large, calls for some extra effort on the part of your 

students. Teachers who have tried it report that the 

outcome is worth the effort. The contacts you and your 

students make now will be vital through the units that 

follow and even after this curriculum is completed. 

Your students, their families, and your entire 

community will be empowered to prepare wisely for 

the possibility of an earthquake or other destructive 

natural phenomenon. 
1.1 

TEACHING CLUES AND CUES

At the end of this activity, collect the assignments and hold onto 

them until you have 

done the last lesson 

RATIONALE 

This preassessment activity is designed to focus your students on what 

they are about to learn, assess their current knowledge, and later 

provide them and you with a gauge of what they have learned from 

this earthquake curriculum. 

FOCUS QUESTIONS 

What do you know about earthquakes and earthquake preparedness? 

What would you like to learn from these lessons? 

you plan to teach from this 

curriculum before the postassessment activity. You will use them 

again in postassessment. 

OBJECTIVES 

Students will: 

1. Use various writing styles to describe a hypothetical earthquake. 

2. Anticipate what they will learn in this study of earthquakes.

MATERIALS

 Writing paper and pens 

 Student copies of Master 1.1a, Writing Outlines (three pages) 

 Classroom computers (optional) 

 Pictures or slides of earthquake damage (optional: See Unit Resources.)

PROCEDURE

A. Introduction 

Show a selection of images to familiarize students with the kind of 

damage earthquakes can cause. Tell students that they are going to 

draw on the knowledge they already have about earthquakes to invent 

a specific quake and imagine themselves in it. Distribute copies of the 

writing outlines, Master 1.1a, and ask each student to note the date and 

time of their quake, its location, how much damage it caused, and 

other basic information at the top of page 1. 

AGU / FEMA 3 S EISMIC S LEUTHS
TEACHING CLUES AND CUES

The newspaper 

accounts on Master 5.1a 

are examples of how 

news articles are written.

This activity is purely 

diagnostic. Explain to 

students that you do not 

expect professional 

B. Lesson Development 

Now tell students that each of them is going to write about his or her 

hypothetical earthquake from three different points of view: that of a 

news reporter, a scientist, and an individual directly affected by the 

quake. Each of the three accounts will describe the same earthquake, 

but the styles of the three will vary. 

News Reporter—a short, concise article describing the who, what, 

where, and when of the earthquake and providing information the 

public needs. 

Scientist—a scientific account stating what is objectively known about 

the earthquake: its causes, its effects, its magnitude and/or intensity, 

and the likelihood of its recurrence, if known. 

Eyewitness—a personal letter to a friend telling about being in an 

earthquake. This will describe what happened to the student, to the 

building in which the student was, to family members and pets, and to 

the family home during the earthquake. Have students describe what 

they had done before the earthquake to be prepared, how effective 

their preparations were, what life was like in the two weeks following 

the earthquake, and what they would do differently in preparation for 

the next earthquake. 

Tell students to feel free to make up information, quotations, etc., but 

to keep the basic facts consistent from one essay to another. Since, in 

real life, compositions of the second and third type are likely to be 

written later than news accounts, however, some discrepancies in 

details are to be expected.

scientific writing—only their best try 

on the basis of what they already 

know.

C. Conclusion 

Ask students to talk about the experience of writing the accounts. Ask: 

 Did you feel you had enough information to do the job in each 

case? 

 Did some of you wish you knew more? Is there anything specific 

you’d like to find out? 

 Was one point of view more comfortable than the others? Were 

some accounts easier to write? 

Discuss the validity of the different points of view. Emphasize that 

each kind of account is valuable in its own right. 

ADAPTATIONS AND EXTENSIONS 

1. If time is short, form groups of three students each. Have each 

student develop one point of view and share it with the group. 

2. If this assessment reveals that students have very little basic 

information about earthquakes, you may want to spend class time with 

some of the books or videos in the Unit 2 resource list before 

proceeding. 

3. Invite students to write about an earthquake from a premodern point 

of view, such as that of a Native American in North America before 

Columbus. Alternatively, students may write from the viewpoint of a 

traditional culture with which they are familiar. 

AGU / FEMA 4 S EISMIC S LEUTHS
4. Invite students to bring in samples of writing about earthquakes and TEACHING CLUES AND CUES

classify them as journalistic, scientific, or informal. This could make a 

long-term bulletin board display. S

If you have access to 

enough computers, 

encourage students to 

compose their accounts 

on a classroom computer and save 

the files. This will make it easy to 

rewrite them later as a postassessment activity. 

AGU / FEMA 5 S EISMIC S LEUTHS
AGU / FEMA 6 S EISMIC S LEUTHS
1.1a MASTER PAGE Writing

Name Date 

Just the facts: 

Date and time of the hypothetical earthquake_____________________________________ 

Location (city, state, country)__________________________________________ 

Estimated strength and impact 

Richter magnitude______________ Deaths____________ 

Injuries_______________________ Property damage $___________ 

Maximum Mercalli intensity if known (I-XII)______________ 

Date of last earthquake in this region____________________________ 

Use these same facts in each of the three variations that follow.

1. Newspaper account: intended for the general public, who need practical information. May appear immediately 

after the quake, while aftershocks are still occurring and emergency conditions are still in effect. 

Dateline (place and time of filing story)____________________ 

Lead sentence—must be catchy, attention-grabbing. May be a particularly startling fact or a quotation (make it 

up) from a person in authority, an expert, or an eyewitness. 

Rest of lead paragraph—must answer what, where, when, who was affected, and how. (May use quotations.) 

One or more body paragraphs—provide background. Add more details on effects, quotations from more people, 

possible explanation, analysis. (Think of what people need to know—what to do, where to go, what to watch for.) 

Final sentence—the clincher; ends story with a punch. (Possibly a warning about aftershocks?) 

AGU / FEMA 7 S EISMIC S LEUTHS
MASTER PAGE 

2. Scientific account: intended for specialists; will probably appear well after the dust has settled. 

AGU / FEMA 8 S EISMIC S LEUTHS

Lead paragraph—must answer what, where, when, who was affected, and how. Likely to be heavy with data 

instead of quotations. (Make them up too, but keep them consistent with the basic data at the top of page 1.) 

One or more body paragraphs—provide background and analysis, more details on effects, maybe quotations from 

experts, scientific explanations, and hypotheses. (Will probably compare original and revised estimates of severity 

and effects, compare earthquake to other quakes.) 

Final paragraph—summarizes what scientific knowledge has been gained or what plans are underway to gather 

information as a result of the earthquake. 
MASTER PAGE 

3. Informal account: intended for a friend, usually also written after the worst is over; may include humor or 

exaggeration. 

[inside address] 

Name

Street no., Apt. no. 

City/State/Zip 

Date 

Dear [name], 

Your friend, 

__________________________________ 

AGU / FEMA 9 S EISMIC S LEUTHS
AGU / FEMA 10 S EISMIC S LEUTHS
1.2 

VOCABULARY

Earthquake: a sudden 

shaking of the ground 

caused by the passage 

of seismic waves. These 

waves are caused by the release of 

energy stored in the Earth’s crust. 

Natural hazard: any of the range of 

natural Earth processes that can 

cause injury or loss of life to human 

beings and damage or destroy 

human-made structures.

RATIONALE 

Students will consider the range of their needs and the state of their 

personal preparedness for an emergency. 

FOCUS QUESTIONS 

What do people need to survive? 

What kinds of natural events can prevent people from meeting their 

basic needs? 

How does society cope with these events? 

OBJECTIVES 

Students will: 

1. Distinguish between luxuries and necessities. 

2. Describe their own experience with severe weather or natural 

disasters, and how they and their families fared. 

3. Explain why preparedness can help individuals and families cope 

effectively in the event of an earthquake or other natural disaster.

MATERIALS

 Chart paper 

 Felt markers 

 Student copies of Master 1.2a, Three-Day Survival Pack 

 Transparency made from Master 5.5b, A Chain of Disasters (optional)

 Overhead projector (optional)

 Materials for assembling the Three-Day Survival Pack (optional)

PROCEDURE

A. Introduction 

Ask students to consider which of all the things they use and consume 

every day are really essential to their survival. Discuss, and develop a 

class listing on chart paper. (Answers may include variations on water, 

food, clothing, and shelter.) 

AGU / FEMA 11 S EISMIC S LEUTHS
AGU / FEMA 12 S EISMIC S LEUTHS

TEACHING CLUES AND CUES

Please save the lists 

students develop in this 

lesson. You will use 

them again later in this

Ask: How do you meet these needs? (Answers will include faucets, 

restaurants, grocery stores or parents’ refrigerators, school cafeterias, 

clothing stores, parents’ homes.) Now ask students to name some 

natural occurrences that could cut them off from these sources, and 

describe their own experiences with snowstorms, hurricanes, floods, or 

earthquakes. Beyond their own experience, what events of this type 

have they heard or read about in the last two years? Develop a list of 

events. 

lesson and in Unit 5, lesson 5.

To help students understand why electricity, 

natural gas, and other 

services would be

disrupted by an earthquake, you may 

want to project a transparency made 

from Master 5.5b, A Chain of 

Disasters.

Many scientists prefer 

the term natural hazard

to natural disaster

because proper 

B. Lesson Development 

1. Elicit a definition of natural hazards from the class. Emphasize that 

earthquakes, volcanoes, floods, hurricanes, tsunami, and similar events 

are the result of natural processes in the life of our dynamic Earth. 

These processes have shaped our Earth and created the beauty of 

mountains, valleys, lakes, and rivers. Be sure students understand the 

difference between natural events and those caused by human activity. 

2. Ask: If an earthquake occurs in an uninhabited region, and has no 

impact on human beings or human property, is it a disaster? (Not for 

human beings, though it may be for other life forms.) Are we able to 

control natural events, or accurately predict when they will occur? (No, 

but students may be aware of instances in which human activity has 

influenced natural events, as in the relationship between dams and 

floods, and of our relative success in predicting some meteorological 

events.) Lead students to the conclusion that because our ability to 

control natural events, or even predict when they will occur, is still 

very limited, people have a responsibility to plan how they would cope 

if an earthquake or other destructive event struck their community. 

preparation can avert disaster, 

preventing or minimizing injury and 

damage. This curriculum encourages 

students to take a proactive role in 

preparing themselves and their 

community to survive destructive 

natural events.

3. Ask students how they and their families coped with any destructive 

events they have experienced. Were their homes equipped with 

everything they needed? Did they have to leave their homes? Were the 

roads open? Were the stores open? Who provided help? (If personal 

experiences are lacking, discuss recent news accounts of earthquakes, 

floods, and storms.) 

4. Look again at the list of vital necessities and widen the discussion to 

include the needs of communities as well as individuals. Ask: If a 

major earthquake occurred in or near your community, what 

necessities would have to be added to the first list? (Answers may 

include medical care, electrical power and other utilities, and essential 

transportation—for hospital workers, police, firefighters, and people 

who supply food, water, and other necessities.) 

Emphasize that a damaging earthquake would disrupt all or most of the 

community’s lifelines—its supplies of water and power and its 

transportation and communications systems. Emergency services, such 

as police, fire departments, and emergency medical technicians, would 

be severely taxed and unable to answer all calls for assistance. For this 

reason, individuals, families, and neighborhoods must be prepared to 

be self-sufficient for at least 72 hours. 
AGU / FEMA 13 S EISMIC S LEUTHS

TEACHING CLUES AND CUES

In assembling the survival pack, group can 

openers and other utensils in one container so 

they’ll be easy to find. 

Suggest that families 

assemble a smaller version of the pack to keep 

in the trunk of the car. 

C. Conclusion 

Distribute student copies of Master 1.2a, Three-Day Survival Pack. 

Explain its purpose. The Federal Emergency Management Agency 

(FEMA) and law enforcement authorities recommend that every family 

assemble a pack like this and keep it handy in their home for 

emergencies, checking it periodically to keep it up to date. (Batteries 

may need replacing, family needs may have changed.) Compare this list 

with the lists students have developed. If your school is in a high-risk 

zone, you may want to prepare a variation of the survival pack to keep in 

your classroom. 

Ask students to take the sheet home and encourage the members of their 

household to cooperate in filling a clean trash can or other suitable 

container with these supplies. Make sure that everyone knows its 

location. 

Tell students that in the following lessons they will learn more about one 

type of natural hazard, earthquakes. They will also research their own 

community’s potential to survive destructive natural events, especially 

earthquakes. 

ADAPTATIONS AND EXTENSIONS 

1. In section A., Introduction, instead of a class discussion, you might 

ask individuals or small groups to develop lists of essentials they would 

need to survive 72 hours without access to power, running water, roads, 

stores, and so on. Then challenge each student or group to justify the 

items on their list, and develop a class list from the items that most 

students agree are essential. Compare this list with Master 1.2a when it is 

distributed. 

2. Make a list of the daily activities that involve electricity, water, natural 

gas, telephone, and transportation. Then enlist the cooperation of parents 

in an at-home recovery simulation. For a period of 24 hours 

(representing 72 hours), ask students to do without things that would not 

be available after an earthquake—telephone or other communication, 

nonessential transportation, electricity, gas, and running water. 

Alternatively, consider involving the administration and the other 

teachers in an in-school simulation. With preplanning, heat or cooling 

could be turned down, lessons in every subject could be earthquakerelated, and lunch could feature emergency rations. S
AGU / FEMA 14 S EISMIC S LEUTHS
1.2a MASTER PAGE Three-Day Survival Pack

TOP OF THE BARREL 

Flashlight and radio with batteries 

First aid kit, including: 

Medicines Dressings 

Antibiotic ointment Adhesive tape, 2” wide roll 

Aspirin, acetaminophen, or 

ibuprofen 

Sterile bandage, 2” and 4” 

rolls 

Ipecac (to induce vomiting) Large triangular bandages 

Kaopectate Band-aids

Prescription medications 

(insulin, heart tablets) 

Cotton-tipped swabs 

Sterile absorbent cotton 

Ace bandage 

Butterfly bandages 

Gauze pads, 4” x 4” 

Latex gloves 

Other Supplies

Scissors 

Tweezers 

Thermometer 

Petroleum jelly 

Rubbing alcohol 

Tissues & toilet paper 

Pocketknife 

First-aid handbook

Emergency instructions 

Waterproof page with phone 

numbers, when & how to 

turn off utilities, meeting 

places, etc.

MIDDLE OF THE BARRELL 

Water (4 liters [about 1 gal] per person) 

Three-day supply of food

 Choose food that does not require refrigeration. 

 Date all food items. 

 Write out a menu for each day. 

Suggested foods (1/2 lb. per person): 

Canned tuna Graham crackers 

Canned beans Dried apricots 

Nonfat dry milk Peanut butter 

Powdered juice mixes Pet food if necessary 

Canned juices 

BOTTOM OF THE BARREL 

Bedding

Sleeping bags or blankets 

Plastic sheet or tarp

Infant supplies, 

if necessary

Other 

Water purification 

tablets

Personal supplies Fuel and light

Toiletries

Towel 

Books 

Paper and pencil 

Cash

Matches 

Candle 

Signal flare 

Canned heat (Sterno) 

Extra batteries

Equipment 

Can opener

Dishpan 

Disposable dishes

Disposable utensils 

Ax 

Shovel 

Bucket and plastic bag 

liners

Chlorine bleach 

Eye dropper 

Clothing

One change per person 

 Place pack in convenient place known to all family members. Keep a smaller version in the trunk of your car.

 Keep items in airtight bags.

 Change stored water every three months. Check and rotate food every six months. Mark dates on your calendar. 

 Rethink kit once a year. Update supplies and replace batteries, outgrown clothing, and perishables. 

AGU / FEMA 15 S EISMIC S LEUTHS
AGU / FEMA 16 S EISMIC S LEUTHS
AGU / FEMA 17 S EISMIC S LEUTHS

1.3 

Investigating Community 

Preparedness 

TEACHING CLUES AND CUES

The other early lessons 

in Unit 1 will be revisited 

in Unit 6. This one will 

culminate in a major 

RATIONALE 

Now that students have thought seriously about individual survival in 

the event of a natural disaster, it is time for them to learn about their 

community’s survival plans. 

FOCUS QUESTIONS 

How would your community cope in the event of an earthquake or 

other natural disaster? 

Who are the people responsible for your community’s survival and 

recovery? 

simulation in Unit 6, but it will also be 

woven throughout Units 2 to 5. The 

classroom map will play a major role 

in this continuing development, so it 

is worth the time you spend on it 

now.

OBJECTIVES 

Students will: 

1. Adopt and begin to research individual roles in community 

earthquake planning, management, and follow-up. 

2. Set up a classroom map for further elaboration. 

3. Begin a process of learning through and with the community that 

continues throughout this entire curriculum.

MATERIALS

 Master 1.3a, Preparedness People 

 Local map 

 Transparency made from Master 1.3b, U.S. Earthquake Hazard 

Map 

 Extra transparency sheets 

 Overhead projector 

 A square of sturdy paper, 1 m x 1 m or larger 

 Paper, pens, envelopes, and stamps for writing letters 

 Markers in a variety of colors
TEACHING CLUES AND CUES

If you and your class 

determine that the seismic risk for your area is 

very low, you may want 

to expand your focus to include 

hazards of greater local concern, 

such as tornadoes or other storms or 

flooding. Keep earthquakes in focus 

as well, however. Remind students 

that most of them will move several 

times in the course of their lives and 

that earthquakes can happen 

anywhere. 

Outside of class, write or 

call the “preparedness 

people” in your community to let them know

PROCEDURE

Teacher Preparation 

1. Look at Master 1.3a, Preparedness People, and add or subtract items 

as necessary to fit your community and the number of students in each 

class. Make a transparency from your list. 

2. Find a map, or a portion of a map, that includes your students’ 

homes and one or more local governments. Copy the map onto a 

transparency sheet. 

3. Decide whether to assign roles, allow students to choose them, or 

hold elections, at least for the major roles. If the class is very large, 

you may want to assign more than one student for some roles. 

4. Find out who is responsible for emergency response in your school 

building. Notify this person of your plans to teach about earthquakes. 

Notify the administration and fellow teachers as well, and enlist their 

cooperation for the long term. 

A. Introduction 

Ask students if they have ever heard the emergency broadcast system 

go into effect on radio or TV. Do they know who is responsible for 

emergency response in their school? If they don’t know, tell them, and 

briefly describe the procedures that would be followed during an 

earthquake. (In most schools, students would drop, cover, and hold 

until the shaking stopped, following their classroom teacher’s 

directions. Then the principal would direct an evacuation similar to 

that during a fire drill. See Unit 5, Lesson 2 for more details.) 

Remind students that an earthquake or other natural disaster in their 

own area would impact large numbers of people. Tell them that in 

Unit 6 each of them will play the role of someone with responsibility 

for the community’s emergency planning and survival. In this unit 

they will adopt that role and begin to learn about it. 

that students will be contacting them 

and why and to enlist their 

cooperation.

This map is drawn along 

state lines for ease of 

use. A map drawn along 

geological boundaries 

B. Lesson Development 

1. Project the U.S. Earthquake Hazard Map, Master 1.3b, and determine how great a seismic hazard is shown for your state or region. 

2. Project the Preparedness People master, and go over the list of roles 

students could assume throughout this curriculum. Incorporate student 

suggestions in developing the final list, then distribute the roles. 

3. Assign students to contact their mentors and set up interviews. Each 

student will interview one individual to learn what the person does 

and what role he or she plays in the community’s earthquake 

preparedness plan. Students may tailor their questions to the person, 

but every interview should include these questions: 

would look quite different and might 

put parts of some states in another 

hazard category.

 What are the current emergency plans for this area? 

 Have they ever been implemented? 

 What is your role during an emergency? 

 How many people answer to you? 

AGU / FEMA 18 S EISMIC S LEUTHS
 What are the lines of communication during an emergency? TEACHING CLUES AND CUES

 What is the budget of this department or organization? 

 How much of this is dedicated for emergency preparedness and 

actual emergencies? 

If more than one class is 

doing this activity, consider sending a group for 

each interview (for 

 May I call you again if I have additional questions? 

 Would you be willing to speak to my class? 

example, one “mayor” from each 

class to interview the mayor 

together). 

Encourage students to take notes, to review their notes after the 

interview, and to make follow-up calls if they find they are missing any 

information. 

4. Assign students to write letters thanking their mentors for the 

interviews. Review the format of a business letter, if necessary. Tell 

students that each letter must include details from the notes taken 

during the interview, so that both the recipient and you, the teacher, 

will know the time was well spent. Collect the letters and mail them 

from the school. 

5. Fasten the large, sturdy sheet of paper to the wall and project the 

map transparency onto the paper. Move the projector away from the 

paper until the image reaches the desired size, then trace the image on 

the paper. 

6. With the class, work out a way to represent all of the following on 

the large area map you have prepared: 

 Hospitals and nursing homes 

 Fire and police stations 

 Power, sewage, and water plants 

 Gas, water, electric, and sewage trunk lines 

 Railroads and other mass transit systems 

 Major roads and highways 

 Telephone systems and other communications systems 

 Schools 

All of these are considered critical facilities or lifeline utility systems. 

Schools are important both because they may house large populations 

to be evacuated and because they frequently serve as centers for 

emergency shelter and the distribution of supplies. 

C. Conclusion 

Display the local map prominently in the front of the classroom. 

Students will add to this map, and to their role knowledge, as they gain 

information throughout these lessons. 

AGU / FEMA 19 S EISMIC S LEUTHS
ADAPTATIONS AND EXTENSIONS 

AGU / FEMA 20 S EISMIC S LEUTHS

1. If your city or metropolitan area is a large one, divide it into regions 

and assign one to each of several classes. If it is small, extend your 

investigation into the surrounding communities. 

2. Assign students to learn as much as they can about disasters that 

have impacted their town or area in the past. They can begin by 

interviewing long-time residents and searching the newspaper archives. 

3. If you do not plan to teach all the units in order, you may want to 

introduce Unit 5, Lesson 5 at this time. S
1.3a MASTER PAGE Preparedness People

All these people and more may play a role in your 

community’s disaster preparedness planning and 

response. 

 Mayor or City Administrator 

 City Manager 

 Public Information Officer 

 Chief of Police 

 Fire Chief 

 Emergency Services Coordinator 

 Superintendent of Schools 

 School District Risk Manager 

 City Building Code Inspector 

 City Council Members 

 City Geologist 

 City Planner 

 Coordinator of Roads and Transportation 

 Director of Public Health 

 Director of Public Works 

 Superintendent of the Sewage Plant 

 Superintendent of the Water Department 

 Electric Company Emergency Officer 

 Gas Company Emergency Officer 

 Telephone Company Emergency Coordinator 

 Hospital Safety and Security Manager 

AGU / FEMA 21 S EISMIC S LEUTHS
AGU / FEMA 22 S EISMIC S LEUTHS
1.3b MASTER PAGE 

AGU / FEMA 23 S EISMIC S LEUTHS
AGU / FEMA 24 S EISMIC S LEUTHS
1 UNIT RESOURCES

BIBLIOGRAPHIES 

National Center for Earthquake Engineering Research 

(NCEER) Information Service. (1995). “Teachers 

Packets, 9-12.” Buffalo, NY: State University of New 

York at Buffalo. 

Seismology Resources for Teachers. Seismological 

Society of America, 21 Plaza Professional Building, 

El Cerrito, CA 94530; 415-525-5474. Includes 

software, databases, and video listings. 

World Amateur Seismological Society. “Reference 

List for Amateur Seismologists.” A list of references 

intended to serve as an introduction to the literature of 

seismology. 

BOOKS 

American Red Cross, Los Angeles Chapter. (1985). 

The Emergency Survival Handbook. In English and 

Spanish. A simple, practical, and easy-to-use guide. 

Federal Emergency Management Agency/National 

Science Teachers Association. Earthquakes—A 

Teacher’s Package for K-6 (Tremor Troop). (FEMA 

159, 1992). Washington, DC: FEMA/NSTA. (FEMA 

Publications, 500 C St. SW, Washington, DC 20472.) 

The Homeowners Guide to Earthquake Safety.

Sacramento, CA: California Seismic Safety 

Commission (1900 K Street, Sacramento, CA 95814). 

Kimball, Virginia. (1992). Earthquake Ready: The 

Complete Preparedness Guide. Malibu, CA: 

Roundtable Publishing, Inc., A practical, nontechnical 

guide to preparation and survival. 

Movers and Shakers. An educational program for 

grades K-12 that includes a video and a two-sided 

classroom poster. Available free to educators by 

writing to Movers and Shakers (E-8), State Farm 

Insurance Companies, One State Farm Plaza, 

Bloomington, IL 61710-0001. 

Plafker, George, and Galloway, John P., eds. (1989). 

Lessons Learned from the Loma Prieta Earthquake of 

October 17, 1989. Denver, CO: U.S. Geological 

Survey, Circular # 1045. Excellent photographs, maps, 

and illustrations. 

Yanev, P. (1991). Peace of Mind in Earthquake 

Country. How to Save Your Home and Your Life.

San Francisco, CA: Chronicle. 

PAMPHLETS AND PERIODICALS 

American Red Cross, Los Angeles Chapter. 27 Things 

to Help You Survive an Earthquake. Los Angeles, CA: 

American Red Cross. (2700 Wilshire Blvd., 

Los Angeles, CA 90057; 213-739-5200.) Poster in 

English and Spanish lists 4 things to do during an 

earthquake, 6 to do afterwards, 14 survival items to 

keep on hand, and 3 essential things to know. 

Earthquakes and Volcanoes. An attractive, 

nontechnical magazine published bimonthly by the 

U.S. Geological Survey to provide current 

seismological information. Washington, DC: U.S. 

Government Printing Office; 202-783-3238; $8/yr. 

Federal Emergency Management Agency pamphlets. 

“Family Earthquake Drill and Home Hazard Hunt,” 

FEMA 113; “Earthquake Safety Checklist,” 

FEMA 46. 

AGU / FEMA 25 S EISMIC S LEUTHS
UNIT RESOURCES 

Harris, J.W. (1980). “Building a Firm Foundation—

Educating about Geologic Disasters.” The Science 

Teacher 47, 9: 22-25. 

“May 18th, 1980: Eyewitness Accounts by 

Cobblestone Readers.” Cobblestone (May 1981): 

pp. 20-23. By and for readers 8-14. This issue has 

several good features on earthquakes. 

“Scientists Predict: Big Quake Will Strike Eastern 

U.S.” Current Science (Jan. 6, 1989): p. 7. For readers 

10-16. 

Teacher’s Packet of Geologic Materials. A collection 

of leaflets, booklets, and reference lists provided free 

by the U.S. Geological Survey, Geologic Inquiries 

Group, 907 National Center, Reston, VA 22092. Send 

request on school letterhead, indicating the subject and 

grade level you teach. 

Westrup, H. “Giant Quake: When Will It Strike?” 

Current Science (Sept. 7, 1990): pp. 4–5. For readers 

10–16. 

NON-PRINT MEDIA 

Earthquake Slides. Photographs of earthquake effects, 

copies of seismograms, and seismicity maps can be 

obtained from the National Geophysical and Solar 

Terrestrial Data Center, Code D62, NOAA/EDS, 

Boulder, CO 80302. 

Earthquake Sound Cassette Tape. Emergency 

Preparedness Committee, Utah State PTA, 1037 East 

South Temple, Salt Lake City, UT 84102; 801/359-

3875. A one-minute tape available for $2, including 

postage. 

EERI Videotapes and Slide Sets. Oakland, CA: 

Earthquake Engineering Research Institute. For 

information, phone 510-451-0905, or fax 510-451-

5411. 

National Earthquake Information Center Seismicity 

Maps. Full-color maps available from USGS/NEIC, 

PO Box 25046, Federal Center, MS 967, Denver, CO 

80225-0046; 303-273-8477. $5–$15 plus $2 shipping. 

Nur, Amos, and MacAskill, Chris. (1991). The Walls 

Came Tumbling Down: Earthquakes in the Holy Land.

Stanford, CA: ESI Productions. Video provides a tour 

along an active fault from the north of Israel to 

Jerusalem. 

Steinbrugge Collection. Richmond, CA: Earthquake 

Engineering Research Center. Over 10,000 

photographs and 5,000 slides of earthquake damage. 

The library will provide copies to teachers and 

researchers. Call 510-231-9401 for information. 

USGS posters plus seismicity maps for most of the 

states. USGS Map and Book Distribution, PO Box 

25286, Federal Center, Building 10, Denver, CO 

80225; 303-236-7477. 

World Seismicity Map. Large 48" x 36" wall map 

shows epicenters, depths of foci, and dates and 

magnitudes of large quakes. Ward’s Natural Science 

Establishment, Inc., 5100 W. Henrietta Road, PO Box 

92912, Rochester, NY 14692-9012; 800-962-2660. 

Note: Inclusion of materials in these resource listings 

does not constitute an endorsement by AGU or FEMA.

AGU / FEMA 26 S EISMIC S LEUTHS
UNIT RESOURCES 

Earthquake Information 

Resource List 

AGU / FEMA 27 S EISMIC S LEUTHS

State Geological 

Survey Offices 

Geological Survey of Alabama 

420 Hackenberry Lane 

P.O. Box O 

Tuscaloosa, AL 35486-9780 

205-349-2852 

Alaska State Geological Survey 

794 University Avenue 

Suite 200 

Fairbanks, AK 99709-3645 

907-474-7147 

FAX: 907-479-4779 

Arizona Geological Survey 

845 North Park Avenue 

Suite 100 

Tucson, AZ 85719 

602-882-4795 

Arkansas Geological Commission 

Vardelle Parham Geology Center 

3815 West Roosevelt Road 

Little Rock, AR 72204 

501-324-9165 

California Division of Mines & Geology 

801 K Street 

Mail Stop 14-33 

Sacramento, CA 95814-3532 

916-323-5336 

Colorado Geological Survey 

1313 Sherman Street 

Room 715 

Denver, CO 80203 

303-866-2611 

FAX: 303-866-2115 

Geological Survey of Connecticut 

Dept. of Environmental Protection 

Natural Resources Center 

165 Capitol Avenue 

Room 553 

Hartford, CT 06106 

203-566-3540 

Delaware Geological Survey 

University of Delaware 

Delaware Geological Survey Building 

Newark, DE 19716 

302-831-2833 

FAX: 302-831-3579 

Geologist of Washington, DC 

Univ. of the District of Columbia 

Dept. of Environmental Science 

4200 Connecticut Avenue, NW 

Washington, DC 20008-1154 

202-282-7380 

FAX: 202-282-3675 

Florida Bureau of Geology 

Florida Dept. of Natural Resources 

903 West Tennessee Street 

Tallahassee, FL 32304 

904-488-9380 

Georgia Geologic Survey 

Georgia Dept. of Natural Resources 

Environmental Protection Div. 

19 M.L. King Jr. Drive, Room 400 

Atlanta, GA 30334 

404-656-3214 

Hawaii Geological Survey 

Div. of Water/Land Development 

Dept. of Land & Natural Resources 

P.O. Box 373 

Honolulu, HI 96809 

808-587-0230 

FAX: 808-587-0219

Idaho Geological Survey 

University of Idaho 

Morrill Hall, Room 332 

Moscow, ID 83843 

208-885-7991 

FAX: 208-885-5826 

Illinois State Geological Survey 

Natural Resources Building 

615 East Peabody Drive 

Champaign, IL 61820 

217-333-5111 

FAX: 217-244-7004 

Indiana Geological Survey 

Dept. of Natural Resources 

611 North Walnut Grove 

Bloomington, IN 47405 

812-855-9350 

FAX: 812-855-2862 

Iowa Dept. of Natural Resources 

Geological Survey Bureau 

123 North Capitol Street 

Iowa City, IA 52242 

319-335-1575 

FAX: 319-335-2754 

Kansas Geological Survey 

University of Kansas 

1930 Constant Avenue 

Campus West 

Lawrence, KS 66047 

913-864-3965 

FAX: 913-864-5317 

Kentucky Geological Survey 

University of Kentucky 

228 Mining & Minerals Resources Bldg. 

Lexington, KY 40506-0107 

606-257-5500 

FAX: 606-257-1147
UNIT RESOURCES 

Louisiana Geological Survey 

Louisiana State University 

P.O. Box G 

Baton Rouge, LA 70893 

504-388-5320 

FAX: 504-388-5328 

Maine Geological Survey 

Dept. of Conservation 

State House Station #22 

Augusta, ME 04333 

207-287-2801 

FAX: 207-287-2353 

Maryland Geological Survey 

Maryland Dept. of Natural Resources 

2300 St. Paul Street 

Baltimore, MD 21218 

410-554-5504 

Massachusetts Office of the State 

 Geologist 

Commonwealth of Massachusetts 

100 Cambridge Street, 20th Floor 

Boston, MA 02202 

617-727-9800 

FAX: 617-727-2754 

Michigan Dept. of Natural Resources 

Geological Survey Div. 

Box 30028 

Lansing, MI 48909 

517-334-6923 

FAX: 517-334-6038 

Minnesota Geological Survey 

University of Minnesota, Twin Cities 

2642 University Avenue 

St. Paul, MN 55114-1057 

612-627-4780 

FAX: 612-627-4778 

Mississippi Office of Geology 

Mississippi Dept. of Environmental 

 Quality 

P.O. Box 20307 

2380 Highway 80 West 

Jackson, MS 39289-1307 

601-961-5500 

FAX: 601-961-5521 

Missouri Dept. of Natural Resources 

Division of Geology & Land Survey 

P.O. Box 250 

Buehler Bldg/111 Fairgrounds Road 

Rolla, MO 65401 

314-368-2100 

FAX: 314-368-2111 

Montana Bureau of Mines & Geology 

Montana Coll. of Min. Sci. & Tech. 

West Park Street 

Main Hall 

Butte, MT 59701 

406-496-4180 

Nebraska Geological Survey 

University of Nebraska – Lincoln 

Conservation and Survey Division 

901 North 17th Street 

113 Nebraska Hall 

Lincoln, NE 68588-0517 

402-472-3471 

Nevada Bureau of Mines & Geology 

University of Nevada, Reno 

Mail Stop 178 

Reno, NV 89557-0088 

702-784-6691 

FAX: 702-784-1709 

New Hampshire Geological Survey 

University of New Hampshire 

Dept. of Earth Science 

117 James Hall 

Durham, NH 03824 

603-862-3160 

FAX: 603-862-2030 

New Jersey Geological Survey 

New Jersey Division of Science & 

 Research 

CN 029 

Trenton, NJ 08626 

609-633-6587 

FAX: 609-633-1004 

New Mexico Bureau of Mines & 

 Mineral Resources 

N.M. Inst. of Mining & Technology 

Campus Station 

Socorro, NM 87801 

505-835-5420 

FAX: 505-835-6333 

New York State Geological Survey 

3136 Cultural Education Center 

Albany, NY 12230 

518-474-5816 

FAX: 518-473-8496 

North Carolina Geological Survey 

Dept. of Environment, Health & Natural 

 Resources 

Box 27687 

Raleigh, NC 27611 

903-733-3833 

North Dakota Geological Survey 

600 East Boulevard 

Bismarck, ND 58505-0840 

701-224-4109 

FAX: 701-224-3682 

Ohio Dept. of Natural Resources 

Division of Geological Survey 

4383 Fountain Square Drive Building 

Columbus, OH 43224-1362 

614-265-6576 

FAX: 614-447-1918 

Oklahoma Geological Survey 

University of Oklahoma 

100 East Boyd 

Energy Center, Room N-131 

Norman, OK 73019-0628 

405-325-3031 

FAX: 405-326-3180 

Oregon Dept. of Geology & Mineral 

 Industries 

800 NE Oregon Street, #28 

Suite 965 

Portland, OR 97232 

503-731-4100 

FAX: 503-731-4066 

Pennsylvania Geological Survey 

Box 2357, 9th Floor 

Harrisburg, PA 17105 

717-787-2169 

FAX: 717-783-7267 

Geological Survey of Puerto Rico 

Dept. de Recursos Naturales 

Munoz Rivera Ave., Stop 3 

San Juan, PR 00906 

809-724-8774 

Geological Survey of Rhode Island 

University of Rhode Island 

Geology Dept. 

315 Green Hall 

Kingston, RI 02881 

401-792-2265 

South Carolina Geological Survey 

South Carolina Mapping Services 

5 Geology Road 

Columbia, SC 29210-9998 

803-737-9440 

South Dakota Geological Survey 

University of South Dakota 

Dept. of Water & Natural Resources 

Science Center 

Vermillion, SD 57069-2390 

605-677-5227 

FAX: 605-677-5895 

AGU / FEMA 28 S EISMIC S LEUTHS
UNIT RESOURCES 

Tennessee Division of Geology 

Dept. of Environment & Conservation 

Dept. of Geology 

701 Broadway, Suite B-30 

Nashville, TN 37243 

615-742-6689 

FAX: 615-742-6594 

Texas Bureau of Economic Geology 

University of Texas, Austin 

University Station, Box X 

Austin, TX 78713-7508 

512-471-1534 

FAX: 512-471-0140 

Utah Geological Survey 

Utah Dept. of Natural Resources 

2363 South Foothill Drive 

Salt Lake City, UT 84109-1491 

801-467-7970 

FAX: 801-467-4070 

Vermont Geological Survey 

Agency of Natural Resources 

103 South Main Street 

Center Building 

Waterbury, VT 05671-0301 

803-244-5164 

FAX: 802-244-4528 

Virginia Division of Mineral Resources 

Dept. of Mines, Minerals & Energy 

Alderman & McCormick Roads 

Charlottesville, VA 22903 

804-293-5121 

FAX: 804-293-2239 

Washington Dept. of Natural Resources 

Geology/Earth Resources 

Mail Stop PY-12 

Olympia, WA 98504 

206-459-6372 

FAX: 206-459-6380 

West Virginia Geological & Economic 

 Survey 

P.O. Box 879 

Morgantown, WV 26507-0879 

304-594-2331 

Wisconsin Geological & Natural History 

 Survey 

University of Wisconsin - Extension 

3817 Mineral Point Road 

Madison, WI 53705 

608-262-1705 

FAX: 608-262-8086

Geological Survey of Wyoming 

State of Wyoming 

P.O. Box 3008, University Station 

Laramie, WY 82071 

307-766-2286 

FAX: 307-766-2605 

Selected Regional & Other USGS 

Offices 

Albuquerque 

Earth Data Analysis Center 

University of New Mexico 

Albuquerque, NM 87131-6031 

505-227-3622 

Anchorage 

Room 101 

4230 University Drive 

Anchorage, AK 99508-4664 

907-786-7011 

Fairbanks 

Box 12, Federal Building 

101 12th Avenue 

Fairbanks, AK 99701 

907-456-0244 

Lakewood 

MS 504, Room 1813 

Building 25, Federal Center 

Denver, CO 80225-0046 

303-236-5829 

Menlo Park 

MS 532, Room 3128 

Building 3 

345 Middlefield Road 

Menlo Park, CA 94025-3591 

415-329-4309 

Reston 

US Geological Survey 

507 National Center 

Reston, VA 22092 

703-648-6045 

Rolla 

MS 231 

1400 Independence Road 

Rolla, MO 65401-2602 

314-341-0851 

Salt Lake City 

USGS-ESIC 

2222 W. 2300 South 

Salt Lake City, UT 84138-1177 

801-524-5652 

Sioux Falls 

EROS Data Center 

Sioux Falls, SD 57198-0001 

605-594-6151 

Spokane 

Room 135 

US Post Office Building 

W. 904 Riverside Avenue 

Spokane, WA 99201-1088 

Stennis Space Center 

Building 3101 

Stennis Space Center, MS 39529 

601-688-3541 

US Department of the Interior 

Room 2650 

1849 C Street NW 

Washington, DC 20240 

202-208-4047 

Eastern Region 

Assistant Chief Geologist 

US Geological Survey 

953 National Center 

Reston, VA 22092 

703-648-6660 

Northeastern Regional Hydrologist 

Water Resources Division 

433 National Center 

Reston, VA 22092 

703-648-5813 

Southeastern Regional Hydrologist 

Water Resources Division 

Suite 160 

3850 Holcomb Bridge Road 

Spalding Woods Office Park 

Norcross, GA 30092 

404-409-7700 

Mapping Applications Center 

12201 Sunrise Valley Drive 

Reston, VA 22092 

703-648-6002 

Central Region 

Director’s Representative & Assistant Chief 

 Geologist 

Box 25046 

911 Denver Federal Center 

Denver, CO 80225 

303-236-5438 

Central Region Hydrologist 

Water Resources Division 

Box 25046 

406 Denver Federal Center 

Denver, CO 80225 

303-236-5920 

AGU / FEMA 29 S EISMIC S LEUTHS
UNIT RESOURCES 

Mid-Continent Mapping Center 

1400 Independence Road 

Rolla, MO 65401 

314-341-0880 

Rocky Mountain Mapping Center 

Box 25046 

Denver Federal Center 

Denver, CO 80225 

303-236-5825 

EROS Data Center 

Sioux Falls, SD 57198-0001 

705-594-6123 

(For map and book orders) 

Branch of Distribution 

Box 25286 

Building 810 

Denver Federal Center 

Denver, CO 80225 

303-236-7477 

ESIC Open-File Report Sales 

Box 25286, Building 810 

Denver Federal Center 

Denver, CO 80225 

303-236-7476 

(For report orders) 

Western Region 

Director’s Representative 

MS 144 

US Geological Survey 

345 Middlefield Road 

Menlo Park, CA 94025 

415-329-4002 

Western Region Hydrologist 

Water Resources Division 

MS 470 

US Geological Survey 

345 Middlefield Road 

Menlo Park, CA 94025 

415-329-4414 

Western Mapping Center 

US Geological Survey 

345 Middlefield Read 

Menlo Park, CA 94025-3591 

415-329-4524 

Special Assistant to the Director for Alaska 

4230 University 

Anchorage, AK 99508-4664 

907-786-7001

Alaska Volcano Observatory 

4200 University Drive 

Anchorage, AK 99508 

907-786-7497 

Branch of Atlantic Marine Geology 

Gosnold Building 

Quissett Campus 

Woods Hole, MA 02543 

508-548-8700 

Cascades Volcano Observatory 

David A. Johnston Building 

5400 MacArthur Blvd. 

Vancouver, WA 98661 

206-696-7693 

Center for Coastal and Regional Marine 

 Studies 

600 Fourth St. S. 

St. Petersburg, FL 33701 

813-893-3100 

Flagstaff Field Center 

2255 N. Gemini Drive 

Flagstaff, AZ 86001 

602-556-7151 

Hawaiian Volcano Observatory 

Volcanoes National Park 

Hilo, HI 96718 

808-967-7328 

Hydrologic Information Unit 

US Geological Survey 

419 National Center 

Reston, VA 22092 

703-648-6817 

Geologic Inquiries Group 

US Geological Survey 

907 National Center 

Reston, VA 22092 

703-648-4383

USGS Library 

US Geological Survey 

950 National Center 

Reston, VA 22092 

703-648-4302 

Minerals Information Office 

Corbett Building, Room 340 

North Sixth Avenue 

Tucson, AZ 85705-8325 

602-670-5544

Minerals Information Office 

Room 133 

W. 904 Riverside Avenue 

Spokane, WA 99201 

509-353-2649 

Minerals Information Office 

Mackay School of Mines 

University of Nevada 

Reno, NV 89557-0047 

702-784-5552 

Minerals Information Office 

Room 2647 

Main Interior Building 

1849 C St. NW 

Washington, DC 20240 

202-208-5512 

(a joint USGS/US Bureau of Mines office) 

National Earthquake Information Center 

MS 967 

Denver Federal Center 

Box 25046 

Denver, CO 80225 

303-273-8500

National Landslide Information Center 

MS 966 

Denver Federal Center 

Box 25046 

Denver, CO 80225 

303-273-8587 

National Water Data Exchange 

US Geological Survey 

421 National Center 

Reston, VA 22092 

703-648-5016 

Office of Water Data Coordination 

US Geological Survey 

417 National Center 

Reston, VA 22092 

703-648-5016

Source: American Geological Institute 

U.S. Department of Agriculture 

Soil Conservation Service 

State Offices 

State Conservationist 

USDA Soil Conservation Service 

665 Opelika Road 

Auburn, AL 36830 

205-821-8080, x535

AGU / FEMA 30 S EISMIC S LEUTHS
UNIT RESOURCES 

State Conservationist 

USDA Soil Conservation Service 

949 E. 36th Avenue - Suite 400 

Anchorage, AK 99508-4302 

907-271-2424 

State Conservationist 

USDA Soil Conservation Service 

201 E. Indianola Avenue - Suite 200 

Phoenix, AZ 85012 

602-640-2247 

State Conservationist 

USDA Soil Conservation Service 

5404 Federal Building 

700 W. Capitol Street 

Little Rock, AR 72201 

501-324-5964 

State Conservationist 

USDA Soil Conservation Service 

21221-C Second Street - Suite 102 

Davis, CA 95616-5475 

FTS-757-8200 

916-757-8200 

State Conservationist 

USDA Soil and Conservation 

655 Parfet Street - E200C 

Lakewood, CO 80215-5517 

303-236-0295 

State Conservationist 

USDA Soil Conservation Service 

16 Professional Park Road 

Stoffs, CT 06268-1299 

203-487-4013 

State Conservationist 

USDA Soil Conservation Service 

1203 College Park Drive - Suite A 

Dover, DE 19901-8713 

302-678-4160 

District Conservationist 

Cooperative Extension Service 

901 Newton Street, NE 

Washington, DC 20017 

202-576-6951 

State Conservationist 

USDA Soil Conservation Service 

401 SE lst Avenue - Suite 248 

Gainesville, FL 32601 

904-377-0946 

State Conservationist 

USDA Soil Conservation Service 

Federal Building, Box 13 

355 E. Hancock Avenue 

Athens, GA 30601 

FTS-250-2272 

404-546-2272 

Director, Pacific Basin 

USDA Soil Conservation Service 

602 GCIC Building 

414 W. Soledad Avenue 

Agana, Guam 96910 

671-472-7490 

State Conservationist 

USDA Soil Conservation Service 

300 Ala Moana Blvd - Suite 4316 

Honolulu, HI 96850 

808-541-2601 

State Conservationist 

USDA Soil Conservation Service 

3244 Elder Street - Suite 124 

Boise, ID 83705 

208-334-1601 

State Conservationist 

USDA Soil Conservation Service 

1902 Fox Drive 

Champaign, IL 61820 

217-398-5267 

State Conservationist 

USDA Soil Conservation Service 

6013 Lakeside Blvd 

Indianapolis, IN 46278 

317-290-3200 

State Conservationist 

USDA Soil Conservation Service 

693 Federal Building 

210 Walnut Street 

Des Moines, IA 50309 

515-284-4261 

State Conservationist 

USDA Soil Conservation Service 

760 South Broadway 

Salina, KS 67401 

913-823-4570 

State Conservationist 

USDA Soil Conservation Service 

771 Corporate Drive - Suite 110 

Lexington, KY 40503-5479 

606-233-2749 

State Conservationist 

USDA Soil Conservation Service 

3737 Government Street 

Alexandria, LA 71302 

318-473-7751 

State Conservationist 

USDA Soil Conservation Service 

5 Godfrey Drive 

Orono, ME 04473 

207-581-3446 

State Conservationist 

USDA Soil Conservation Service 

301 John Hanson Business Center 

339 Busch’s Frontage Road 

Annapolis, MD 21401 

410-757-0861 

State Conservationist 

USDA Soil Conservation Service 

451 West Street 

Amherst, MA 01002 

413-256-0441 

State Conservationist 

USDA Soil Conservation Service 

1405 S. Harrison Road - Suite 101 

East Lansing, MI 48823-5202 

517-337-6702 

State Conservationist 

USDA Soil Conservation Service 

600 Farm Credit Building 

375 Jackson Street 

St. Paul, MN 55101-1854 

612-290-3675 

State Conservationist 

USDA Soil Conservation Service 

1321 Federal Building 

100 W. Capitol Street 

Jackson, MS 39269 

601-965-5205 

State Conservationist 

USDA Soil Conservation Service 

Parkade Center - Suite 250 

601 Business Loop, 70 West 

Columbia, MO 65203 

314-876-0903 

State Conservationist 

USDA Soil Conservation Service 

443 Federal Building 

10 E. Babcock Street 

Bozeman, MT 59715-4704 

406-587-6813 

AGU / FEMA 31 S EISMIC S LEUTHS
UNIT RESOURCES 

State Conservationist 

USDA Soil Conservation Service 

345 Federal Building 

100 Centennial Mall North 

Lincoln, NE 68508-3866 

402-587-6813 

State Conservationist 

USDA Soil Conservation Service 

Bldg. F - Suite 201 

5301 Longley Lane 

Reno, NV 89511 

702-784-5863 

State Conservationist 

USDA Soil Conservation Service 

Federal Building 

Durham, NH 03824 

603-868-7581 

State Conservationist 

USDA Soil Conservation Service 

1370 Hamilton Street 

Somerset, NJ 08873 

908-246-1662 

State Conservationist 

USDA Soil Conservation Service 

517 Gold Avenue, NW - Suite 3301 

Albuquerque, NM 87102-3157 

505-766-2173 

State Conservationist 

USDA Soil Conservation Service 

771 Hanley Federal Building 

100 S. Clinton Street 

Syracuse, NY 13260-7248 

315-423-5521 

State Conservationist 

USDA Soil Conservation Service 

4405 Bland Road - Suite 205 

Raleigh, NC 27609 

919-790-2888 

State Conservationist 

USDA Soil Conservation Service 

278 Federal Building 

220 E. Rosser Avenue 

Bismarck, ND 58502-1458 

701-250-4421 

State Conservationist 

USDA Soil Conservation Service 

200 N. High Street - Suite 522 

Columbus, OH 43215-2478 

614-469-6962 

State Conservationist 

USDA Soil Conservation Service 

Agriculture Center Building 

Farm Road & Brumley Street 

Stillwater, OK 74074 

405-624-4360 

State Conservationist 

USDA Soil Conservation Service 

1640 Federal Building 

1220 SW 3rd Avenue 

Portland, OR 97204 

503-326-2751 

State Conservationist 

USDA Soil Conservation Service 

1 Credit Union Place - Suite 340 

Wildwood Center 

Harrisburg, PA 17110-2993 

717-782-2202 

Director, Caribbean Area 

USDA Soil Conservation Service 

P.O. Box 364868 

San Juan, PR 00936-4868 

809-766-5206 

State Conservationist 

USDA Soil Conservation Service 

46 Quaker Lane 

West Warwick, RI 02893 

401-828-1300 

State Conservationist 

USDA Soil Conservation Service 

950 Thurmond Federal Building 

1835 Assembly Street 

Columbia, SC 29201 

803-765-5681 

State Conservationist 

USDA Soil Conservation Service 

Federal Building 

200 Fourth Street, SW 

Huron, SD 57350-2475 

605-353-1783 

State Conservationist 

USDA Soil Conservation Service 

675 Kefauver Federal Building 

801 Broadway Street 

Nashville, TN 37203 

615-736-5471 

State Conservationist 

USDA Soil Conservation Service 

Poage Federal Building 

101 S. Main Street 

Temple, TX 76501-7682 

817-774-1214 

State Conservationist 

USDA Soil Conservation Service 

4402 Bennett Federal Building 

125 S. State Street 

Salt Lake City, UT 84138 

801-524-5050 

State Conservationist 

USDA Soil Conservation Service 

69 Union Street 

Winooski, VT 05404 

802-951-6785 

State Conservationist 

USDA Soil Conservation Service 

9201 Federal Building 

400 N. 8th Street 

Richmond, VA 23240 

804-771-2455 

State Conservationist 

USDA Soil Conservation Service 

Rock Pointe Tower II 

W. 316 Boone Avenue - Suite 450 

Spokane, WA 99201-2348 

509-353-2337 

State Conservationist 

USDA Soil Conservation Service 

75 High Street - Suite 301 

Morgantown, WV 26505 

304-291-4151 

State Conservationist 

USDA Soil Conservation Service 

6515 Watts Road - Suite 200 

Madison, WI 53719-2726 

608-264-5577 

State Conservationist 

USDA Soil Conservation Service 

3124 Federal Building 

100 East B Street 

Casper, WY 82601 

307-261-5201 

Source: U.S. Department of Agriculture 

FEMA Regional Earthquake Program 

Managers 

Earthquake Program Manager 

FEMA Region 1 - NT 

442 J.W. McCormack POCH 

Boston, MA 02109-4595 

Earthquake Program Manager 

FEMA Region 2 - NT 

26 Federal Plaza 

New York, NY 10278-0002 

AGU / FEMA 32 S EISMIC S LEUTHS
UNIT RESOURCES 

Earthquake Program Manager 

FEMA Caribbean Office 

P.O. Box 70105 

San Juan, PR 00936 

Earthquake Program Manager 

FEMA - Region 3 

105 S. Seventh St. 

Philadelphia, PA 19106-3316 

Earthquake Program Manager 

FEMA - Region 4 - NT 

1371 Peachtree Street, NE 

Atlanta, GA 30309-3108 

Earthquake Program Manager 

FEMA Region 5 - NT 

175 West Jackson 

Chicago, IL 60604-2698 

Earthquake Program Manager 

FEMA Region 6 - NT 

800 North Loop 288 

Denton, TX 76201-3698 

Earthquake Program Manager 

FEMA Region 7 - NT 

911 Walnut Street 

Kansas City, MO 64106-2085 

Earthquake Program Manager 

FEMA Region 8 - NT 

Denver Federal Center 

Denver, CO 80225-0267 

Earthquake Program Manager 

FEMA Region 9 - NT 

Presidio of SF, Bldg 105 

San Francisco, CA 94129-1250 

Earthquake Program Manager 

FEMA Region 10, NT 

130 - 228th St., S.W. 

Bothell, WA 98021-9796

State Emergency Management 

Directors and State Earthquake 

Program Managers

Alaska

Director 

Alaska Division of Emergency Services 

New Anchorage Armory 

Building 49000, Suite B-210 

P.O. Box 5750 

Fort Richardson, AK 99505-5750 

907-428-7000 

(FAX) 907-428-7009 

Earthquake Program Manager 

907-428-7022 

(FAX) 907-428-7009 

Arizona

Director 

Arizona Division of Emergency Services 

5636 E. McDowell Road 

Phoenix, AZ 85008 

602-231-6245 

(FAX) 602-231-6231 

Earthquake Program Manager 

602-231-6238 

(FAX) 602-231-6231 

Arkansas

Director 

Arkansas Office of Emergency Services 

P.O. Box 758 

Conway, AR 72032 

501-329-5601 

(FAX) 501-327-8047 

Earthquake Preparedness Program 

 Supervisor 

Earthquake Preparedness Program 

501-329-5601 

(FAX) 501-327-8047 

California

Director 

Governor’s Office of Emergency Services 

State of California 

2800 Meadowview Road 

Sacramento, CA 25832-1499 

916-427-4990 

(FAX) 916-427-4215 

Deputy Director 

Governor’s Office of Emergency Services 

1110 E. Green Street, Suite 300 

Pasadena, CA 91106 

818-304-8388 

(FAX) 818-795-2030 

Northern/Bay Area/Coastal

Earthquake Program Manager 

101 8th Street, Suite 152 

Oakland, CA 94607 

510-540-2713 

Southern California

Earthquake Program Manager 

1110 East Green Street 

Suite 300 

Pasadena, CA 91106 

818-304-8383 

Colorado

Director 

Office of Emergency Management 

Camp George West 

Golden, CO 80401-3997 

303-273-1622 

(FAX) 303-273-1795 

Connecticut

State Director 

Office of Emergency Management 

360 Broad Street 

Hartford, CT 06105 

203-566-3180/4338 

(FAX) 203-247-0664 

Georgia

Executive Director 

Georgia Emergency Management Agency 

P.O. Box 18055 

Atlanta GA 30316-0055 

404-624-7000 

(FAX) 404-624-7205 

Earthquake Program Manager 

404-624-7000 

(FAX) 404-624-7205 

Guam

Director of Civil Defense 

Guam Emergency Services Office 

Territory of Guam 

P.O. Box 2877 

Agana, Guam 96910 

671-477-9841 

(FAX) 671-477-3727 

Earthquake Program Manager 

Civil Defense 

671-477-9841/9842 

(FAX) 671-477-3727 

AGU / FEMA 33 S EISMIC S LEUTHS
UNIT RESOURCES 

Hawaii

Vice Director of Civil Defense 

Department of Defense 

3949 Diamond Head Road 

Honolulu, HI 96816 

808-734-2161 

(FAX) 808-737-4150 

Earthquake Program Manager 

Hawaii State Civil Defense 

808-734-2161 

(FAX) 808-737-4150 

Idaho

State Earthquake Program Coordinator 

Idaho Bureau of Disaster Services 

650 West State Street 

Boise, ID 83720 

208-334-3460 

(FAX) 208-334-2322 

Earthquake Program Manager 

208-334-3460 

(FAX) 208-334-2322 

Illinois

Acting Director 

Illinois Emergency Management Agency 

110 East Adams Street 

Springfield, IL 62706 

217-782-2700 

(FAX) 217-782-2589 

Chief, Division of Planning 

217-782-4448 

(FAX) 217-782-2589 

Indiana

Director 

Indiana State Emergency Management 

 Agency 

Indiana Government Center 

Center South, Suite E-208 

302 West Washington Street 

Indianapolis, IN 46204 

317-232-3830 

(FAX) 317-232-3895 

Iowa

Administrator 

Iowa Emergency Management Division 

Hoover State Office Building 

Level A, Room 29 

Des Moines, IA 50319 

515-281-3231 

(FAX) 515-281-7539 

Kansas

Deputy Director 

Division of Emergency Preparedness 

P.O. Box C-300 

Topeka, KS 66601 

913-266-1400 

(FAX) 913-266-1129 

Kentucky

Executive Director 

Kentucky Disaster and Emergency 

 Services 

EOC Building, Boone Center 

Frankfort, KY 40601-6168 

502-564-8680 

(FAX) 502-564-8614 

Earthquake Program Manager 

502-564-8628 

(FAX) 502-564-8614 

Maine

Director 

Maine Emergency Management Agency 

State House Station 72 

Augusta, ME 04233 

207-289-4080 

(FAX) 207-289-4079 

Earthquake Program Manager 

207-2870-4029 

Massachusetts

Director 

Massachusetts Emergency Management 

 Agency 

400 Worcester Road 

P.O. Box 1496 

Framingham, MA 01701 

508-820-2003 

(FAX) 508-820-2030 

Earthquake Program Manager 

Massachusetts Earthquake Hazards 

 Reduction Program 

508-820-2000 

(FAX) 508-820-2030 

Mississippi

Director 

Mississippi Emergency Management 

 Agency 

P.O. Box 4501, Fondren Station 

Jackson, MS 39296-4501 

601-352-9100 

(FAX) 601-352-8314 

Earthquake Program Manager 

601-960-9978 

(FAX) 601-352-8314 

Missouri

Director 

State Emergency Management Agency 

P.O. Box 116 

Jefferson City, MO 65102 

314-751-9779 

(FAX) 314-634-7966 

Earthquake Program Manager 

314-751-9574 

(FAX) 314-634-7966 

Montana

Administrator 

Montana Disaster and Emergency Services 

 Division 

P.O. Box 4789 

Helena, MT 59604-4789 

406-444-6911 

(FAX) 406-444-6965 

Earthquake Program Manager 

406-444-6911 

Nebraska

Assistant Director 

Nebraska Civil Defense Agency 

1300 Military Road 

Lincoln, NE 68508-1090 

402-473-1410 

(FAX) 402-473-1433 

Earthquake Program Manager 

402-473-2101 

(FAX) 402-473-1433 

Nevada

Director 

Nevada Division of Emergency Management 

2525 South Carson Street/Capitol Complex 

Carson City, NV 89710 

702-887-7302 

(FAX) 702-887-7246 

Earthquake Program Manager 

702-687-4240 

(FAX) 702-887-6788 

New Hampshire

Director 

New Hampshire Office of Emergency 

 Management 

State Office Park South 

107 Pleasant Street 

Concord, NH 03301 

603-271-2231 

(FAX) 603-225-7341 

AGU / FEMA 34 S EISMIC S LEUTHS
UNIT RESOURCES 

Natural Hazards Program Specialist 

603-271-2231 

(FAX) 603-225-7341 

New Jersey

Deputy State Director 

Office of Emergency Management 

New Jersey State Police 

P.O. Box 7068 

West Trenton, NJ 08628 

609-538-6050 

(FAX) 609-538-0345 

New Jersey Office of Emergency Services 

609-538-6012 

New Mexico

Bureau Chief 

New Mexico Emergency Management 

 Bureau 

Department of Public Safety 

4491 Cerrillos Road 

P.O. Box 1628 

Santa Fe, NM 87504 

505-827-3456 

Earthquake Program Manager 

505-827-9254 

(FAX) 505-827-3381 

New York

Director 

New York State Emergency Management 

 Office 

Public Security Building 

State Campus 

Albany, NY 12226-5000 

518-457-2222 

(FAX) 518-457-9930 

Earthquake Project Coordinators 

518-457-9959 

North Carolina

Director 

North Carolina Division of Emergency 

 Management 

116 West Jones Street 

Raleigh, NC 27603-1335 

919-733-3867 

(FAX) 919-733-7554 

Lead Planner, Natural Hazards 

919-733-3627 

(FAX) 919-733-7554 

Oklahoma

Director 

Oklahoma Department of Civil 

Emergency Management 

P.O. Box 53365 

Oklahoma City, OK 73152 

405-521-2481 

(FAX) 405-521-4053 

Oklahoma Earthquake Program Officer 

405-521-2481 

(FAX) 405-521-4053 

Oregon

Administrator 

Oregon Emergency Management Division 

Executive Department 

595 Cottage Street, N.E. 

Salem, OR 97310 

503-378-4124 

(FAX) 503-588-1378 

Earthquake Program Coordinator 

503-378-2911 ext. 237 

Pennsylvania

Director 

Pennsylvania Emergency Management 

 Agency 

P.O. Box 3321 

Harrisburg, PA 17105-3321 

717-783-8016 

(FAX) 717-783-7393 

PMD Chief/Earthquake Program Manager 

Pennsylvania Emergency Management 

Transportation and Safety 

Building B-151 

Harrisburg, PA 17120 

717-783-1048 

(FAX) 717-783-9223 

Puerto Rico

Director 

State Civil Defense Agency 

Commonwealth of Puerto Rico 

P.O. Box 5217 

San Juan, PR 00906 

Deputy Executive Director 

Earthquake Safety Commission 

Commonwealth of Puerto Rico 

P.O. Box 5887 

Puerta de Tierra Station 

San Juan, PR 00906 

809-722-8784 

Rhode Island

Director 

Rhode Island Emergency Management 

 Agency 

State House, Room 27 

Providence, RI 02903 

401-421-7333 

(FAX) 401-751-0827 

Earthquake Program Manager 

Rhode Island Earthquake Project 

401-421-7333 

(FAX) 401-751-0827 

South Carolina

Director 

South Carolina Emergency Preparedness 

 Division 

1429 Senate Street

Columbia, SC 29201-3782 

803-734-8020 

(FAX) 803-734-8062 

Earthquake Program Manager 

803-734-8020 

(FAX) 903-734-8062 

Tennessee

Director 

Tennessee Emergency Management Agency

3041 Sidco Drive 

Nashville, TN 37204 

615-741-0001 

(FAX) 615-242-9635 

Earthquake Program Manager 

615-741-4299 

(FAX) 615-741-0498 

Utah

Director 

Utah Division of Comprehensive Emergency 

 Management 

State Office Building, Room 1110 

Salt Lake City, UT 84114 

801-538-3400 

(FAX) 801-538-3770 

Epicenter Manager 

801-538-3786 

AGU / FEMA 35 S EISMIC S LEUTHS
UNIT RESOURCES 

Vermont

Director 

Vermont Emergency Management Agency 

103 Main Street 

Waterbury, VT 05676 

802-244-8721 

(FAX) 802-244-8655 

Earthquake Program Manager 

Vermont Earthquake Program 

802-244-8721 

(FAX) 802-244-8655 

Virgin Islands

Director 

Virgin Islands Emergency Management 

 Agency 

VITEMA 

131 Gallows Bay 

Christiansted, VI 00820 

809-733-2244 

(FAX) 809-778-8980 

Chief of Planning 

VITEMA 

2C Este Conte 

A & Q Buildings 

Charlotte Amalie 

St. Thomas, VI 00802 

809-774-2244 

Virginia

State Coordinator 

Office of Emergency Services 

310 Turner Road 

Richmond, VA 23225-6491 

804-674-2497 

(FAX) 804-674-2490 

Earthquake Program Manager 

804-674-2442 

(FAX) 804-674-2431 

Washington

Assistant Director 

Washington State Department of 

 Community Development 

Emergency Management Division 

4220 East Martin Way, PT-11 

Olympia, WA 98504 

206-923-4901 

(FAX) 206-438-7395 

State Earthquake Program Coordinator 

206-923-4976 

(FAX) 206-923-4991 

West Virginia

Director 

West Virginia Office of Emergency Services

State Capitol Building, EB-80 

Charleston, WV 25305 

304-558-5380 

(FAX) 304-344-4538 

Wyoming

Coordinator 

Wyoming Emergency Management Agency 

P.O. Box 1709 

Cheyenne, WY 82003 

307-777-7566 

(FAX) 307-635-6017 

Source: Federal Emergency Management 

Agency

AGU / FEMA 36 S EISMIC S LEUTHS
UNIT TWO 
2 INTRODUCTION 

In this unit students will move beyond their own 

personal survival and that of their community, the 

focus of Unit 1, to the big picture of earthquakes in 

space and time. Since the Seismic Sleuths curriculum 

is intended to supplement, and not to replace, your 

school’s own syllabus, it sketches this big picture 

without filling in all the basic earth science 

background. Your preparation to teach these lessons 

must begin with an assessment of your students’ 

readiness. If they have no familiarity with rocks and 

minerals or with faulting and other processes that form 

landscapes, you may need to provide a brief 

introduction from the first few chapters of a high 

school geology or earth science textbook. 

Unit 2 begins with a hands-on activity that models 

what happens when the stresses accumulated at a fault 

are released in an earthquake. Using a box, a board, 

sandpaper, and other simple materials, students apply 

scientific method and basic math skills to measure 

movement, calculate averages, and plot their 

information on a graph. 

The second lesson includes three activities and an 

overview of what is now known about Earth’s evershifting surface and its layered inner structure. In the 

first activity, students will reproduce the magnetic 

evidence for the migration of Earth’s poles in the 

course of tectonic movement. In the second, they see 

how this record is written in the rocks at mid-ocean 

ridges. In the third, they create a map showing the 

arrangement of the continents 120 million years ago, 

and compare it with the map of the world today. As 

students consider several alternative explanations for 

tectonic plate movement, remind them that earth 

science, like the Earth it studies, is constantly in 

motion. Scientific knowledge moves forward through 

questioning and the development of hypotheses into 

theories; its goal is never to provide dogmatic answers. 

The third lesson begins with an exercise in which 

students contrast the small scope of historic time with 

the vastness of geologic time. In the second activity, 

Paleoseismology, they simulate the techniques 

seismologists use to read the record of relatively recent 

earthquakes. 

The amount of damage an earthquake causes depends 

on the strength and duration of the earthquake, on 

population density, on methods of construction (to be 

dealt with in Unit 4), and on the geophysical/ 

geological characteristics of the impacted area. 

Lesson 4 progresses to three of the most potentially 

destructive earthquake effects: liquefaction, landslides, 

and tsunami. Each occurs when a seismic shock 

impacts an area with certain physical characteristics. 

Lesson 5 underlines the importance of site, as students 

interpret maps highlighting different features of the 

landscape. They will draw on their new knowledge to 

make additions to the local map they began in Unit 1. 

AGU / FEMA 38 S EISMIC S LEUTHS
2.1 

RATIONALE 

Students will operate a model to observe the type of motion that 

occurs at a fault during an earthquake and explore the effects of 

several variables. 

FOCUS QUESTIONS 

How much energy will a fault store before it fails? 

Is this quantity constant for all faults? 

OBJECTIVES 

Students will: 

1. Model the frictional forces involved in the movements of a fault. 

2. Measure movement, calculate averages, and plot this information on 

a graph. 

3. Explore the variables of fault strength vs. energy stored. 

MATERIALS 

for each small group

Q1 copy of Master 2.1a, Stick-Slip Data Sheet 

Q4 sandpaper sheets, 23 cm x 28 cm (9 in. x 11 in.), in 60, 120, and 

400 grit (12 sheets) 

QScissors 

QStrapping tape 

Q1-1b box of sugar cubes 

Q8 thumbtacks 

QA box of rubber bands 

Q2 large paper clips 

QYardstick or meter stick 

QAt least 2 m of string 

QLarge dowel or empty tube from a roll of paper towels 

AGU / FEMA 39 S EISMIC S LEUTHS
VOCABULARY 

Fault: a break or fracture in Earth’s crust 

along which movement 

has taken place. 

Friction: mechanical resistance to 

the motion of objects or bodies that 

touch. 

Stick-slip movement: a jerky, 

sliding movement along a surface. It 

occurs when friction between the two 

sides of a fault keeps them from 

sliding smoothly, so that stress is 

built up over time and then suddenly 

released. 

Variable: in a scientific experiment, 

the one element that is altered to test 

the effect on the rest of the system. 

Q Marking pen 

Q Scales 

Q Pine board, approx. 2.5 cm x 30 cm x 1.8 m (1 in. x 12 in. x 6 ft.) 

Q Several books to support one end of the board 

Q Protractor for measuring angles 

Q 1 brick (optional) 

PROCEDURE 

Teacher Preparation 

To assure success, construct the model ahead of time and rehearse the 

activity. Then arrange materials for student models in a convenient 

place. 

A. Introduction 

Elicit a definition of fault from the class, supplementing students’ 

information as necessary until the essential elements have been 

covered. 

Explain to students that when an earthquake occurs and movement 

begins on a fault plane, the movement will not proceed smoothly away 

from the focus. Any change in the amount of friction along the fault 

will cause the fault movement to be irregular. This includes changes 

along the length of the fault and with depth, changes in rock type and 

strength along the fault, and natural barriers to movement, such as 

changes in the direction of the fault or roughness over the surface of 

the fault plane. 

Rupture along a fault typically occurs by fits and starts, in a type of 

sporadic motion that geologists call stick-slip. As energy builds up, the 

rock on either side of the fault will store the energy until its force 

exceeds the strength of the fault. When the residual strength of the 

fault is exceeded, an earthquake will occur. Movement on the fault 

will continue until the failure reaches an area where the strength of the 

rock is great enough to prevent further rupture. In this manner, some 

of the energy stored in the rock, but not all of it, will be released by 

frictional heating on the fault, the crushing of rock, and the 

propagation of earthquake waves. 

B. Lesson Development 

1. Divide the class into working groups of at least four students each. 

Distribute one copy of Master 2.1a, Stick-Slip Data Sheet, to each 

group. Tell students that they are going to model a process, record data 

for each trial, and then vary the process, changing only one variable at 

a time. 

2. Allow groups to assemble their materials, then give these directions: 

a. Fold each piece of 120-grit sandpaper in half lengthwise and cut, to 

produce eight strips of sandpaper, each 11.5 cm x 28 cm (4.5 in. x 

11 in.) in size. 

b. Wrap one of the strips around the box and secure it around the sides 

(not the top and bottom) with two rubber bands. (See diagram.) Weigh 

and record box mass. 

AGU / FEMA 40 S EISMIC S LEUTHS
c. Tape the seven remaining strips of 120-grit sandpaper into one long 

strip. (Be sure to use tape only on the back of the sandpaper.) Now 

attach the sandpaper lengthwise down the center of the pine board, 

using two thumbtacks at each end and being sure the sandpaper is 

drawn tight. 

d. Attach one paper clip to one of the rubber 

bands around the box. 

e. Tie one end of the string onto another paper 

clip and place a mark on the string about 1 cm 

from the clip. Use one rubber band to join the 

paper clip on the box with the paper clip on the 

string. Tie the free end of the string around the 

dowel or paper towel roll. 

f. Tape the meter stick onto the sandpaper strip on 

the board. 

TEACHING CLUES AND CUES 

This part of the activity 

requires a very steady 

hand. 

Controlling the tension 

on the string works best 

if the string is rolled onto 

the dowel until the dowel 

g. Position the box at one end of the board so it is centered on the 

sandpaper. Use books to raise the other end of the board 

approximately 10 cm (4 in.). Measure and record the height. 

h. Gently roll the string onto the dowel until the string lifts off the 

paper and becomes taut. Note the location of the mark on the string 

relative to the meter stick. Take care to keep the dowel in the same 

position during rolling and measurement. 

i. Continue to roll the string onto the dowel until the box moves. The 

box should move with a quick, jumping motion. Record the new 

location of the mark on the string (the distance the box moved) on the 

data table. Continue rolling up the string and recording jump distance 

until the box hits the meter stick. The meter stick can be pulled 

upwards to allow the box to continue to be pulled. 

j. Subtract the beginning measurement from the ending measurement 

or add up the jump measurements to find out how far the box moved. 

Divide by the number of jumps to calculate an average jump distance. 

3. Instruct other students in the same group to change one variable, 

repeat the procedure, and average the distance of the jumps. Students 

may vary the model by adding one or more rubber bands, adding more 

books to change the angle of the board, substituting the brick for the 

box, or using sandpaper of a different grit. If time allows, give every 

student a chance to operate the model with each of the variations. 

4. Ask students to complete their data sheets. 

C. Conclusion 

Ask the class: 

rests on the books and is against the 

edge of the board. 

Q What might the different variables represent in terms of earthquakes 

and landscape conditions? (Number of rubber bands—different 

amounts of energy released; angle of the board—steepness of the 

fault; sandpaper grit size—differences in the amount of force 

AGU / FEMA 41 S EISMIC S LEUTHS
AGU / FEMA 42 S EISMIC S LEUTHS

required for a fault to move—the amount of friction.) Emphasize 

that different faults can store different amounts of energy before 

they fail. Some faults have the potential for generating larger 

earthquakes than others.

QDo the rubber band and string go totally slack after each movement? 

(No.) What does this tell you about the release of stored energy on a 

fault when an earthquake occurs? (No earthquake ever releases all 

the energy stored in the Earth at a particular point. It is because 

some stored energy always remains that one quake may have 

numerous foreshocks and aftershocks, and earthquakes recur 

frequently in some active areas.) V
AGU / FEMA 43 S EISMIC S LEUTHS
2.1 MASTER PAGE Stick-Slip Data Sheet 

Name 

____________________________________________________________ 

Date 

___________________________ 

Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 

Box 

Weight 

Board 

Height 

Sandpaper 

Grit 

Beginning 

Distance 

Jump 1 

Jump 2 

Jump 3 

Jump 4 

Jump 5 

Jump 6 

Jump 7 

Jump 8 

Jump 9 

Jump 10 

Jump 11 

Jump 12 

Jump 13 

Jump 14 

Jump 15 

Total 

Distance 

Average 

Distance 

AGU / FEMA 44 S EISMIC S LEUTHS
AGU / FEMA 45 S EISMIC S LEUTHS
AGU / FEMA 46 S EISMIC S LEUTHS

2.2 

VOCABULARY

Paleomagnetism: the 

natural magnetic traces 

that reveal the intensity 

and direction of Earth’s 

RATIONALE 

To understand earthquakes students need to understand the structure 

of the Earth. The theory of plate tectonics has contributed to an 

understanding of how the Earth’s plates move and how that movement 

can cause earthquakes. 

FOCUS QUESTIONS 

How does the shape of the continents indicate that they were once 

joined? 

What are some of the ways to tell the continents are moving? 

OBJECTIVES 

Students will: 

1. Model magnetic reversal patterns. 

2. Use paleomagnetic data to demonstrate plate motion. 

MATERIALS

Q Master 2.2a, Tectonics Background 

Q Transparency of Master 2.2b, Earth Cross Section 

Q Overhead projector 

Q Master 2.2c, Reading the Patterns 

Q Master 2.2d, Continental Pieces, two copies for each small group 

Q Master 2.2e, World Map Grid 

Q Master 2.2f, World Map Grid, 120 MYA 

Q Classroom world map 

for each small group 

Q Bar or cow magnet 

Q Large nail 

Q Paper clips or staples 

Q Clamp with a handle 

magnetic field in the geologic past.
Q Bunsen burner, cigarette lighter, or other direct heat source 

Q One 3 x 5 file card and sheets of blank paper 

Q Twenty 9 can (3-4 in.) lengths of audiocassette tape (Use an old tape.) 

Q A roll of clear tape 

Q Scissors and a ruler 

Q Pens or pencils 

Q Maps of South America and Africa (optional, but desirable) 

Q Map of the Pacific Ocean floor (optional, but desirable) 

PROCEDURE 

Teacher Preparation 

Practice the magnetizing demonstration before class. Prepare the nail 

by stroking it with a magnet until it will pick up paper clips or staples 

on one end. Place the nail in a clamp and heat it in the middle until the 

clips drop off. 

Read Master 2.2a, Tectonics Background, and decide how much time 

you will need to spend presenting this information to your students. If 

they are already familiar with its outlines, you may just want to 

connect the illustrations with the stick-slip movement students saw in 

the previous activity. 

TEACHING CLUES AND CUES

You may want to take 

students through a quick 

review of magnetic 

properties and the rule 

of 

PART ONE 

POLES AT PLAY

A. Introduction 

Pass out copies of Master 2.2a, Tectonics Background. Project Master 

2.2b, Earth Cross Section, and review the first two major sections of 

Master 2.2a with the students. Point out to students that on a world 

map continental land masses seem to have a jigsaw fit. Early 

mapmakers noted this long ago when drawing the first maps of the 

new world. attraction and repulsion of poles. 

TEACHING CLUES AND CUES

Be sure students understand that it is the magnetic poles that have 

changed, not the 

B. Procedure 

1. Ask the students how magnets work. Some may already know that 

alignment of atomic forces creates the magnetic “pull,” or force field. 

Tell students that when a magnet is heated it loses its magnetic force, 

and when it cools down it again picks up the faint trace of the Earth’s 

magnetic field. Demonstrate this with a nail by stroking it with a 

magnet and then heating it, as explained above. Ask students where 

rocks are heated (in volcanoes and deep within the Earth). Tell them 

that in the next two activities they are going to simulate the process of 

using paleomagnetism to study plate tectonics. 

2. Tell students that in 1963, two English geophysicists, Vine and 

Matthews, were using extremely sensitive magnetometers to make 

measurements of the seafloor across the Mid-Atlantic Ridge. Scientists 

already knew that over the 4.6 billion years of Earth’s history, its 

magnetic poles have changed directions more than once, so that the 

south pole and the north pole have actually switched 

physical ends of the Earth. 

AGU / FEMA 47 S EISMIC S LEUTHS
places. When a volcano erupts, the volcanic rocks record the direction 

of the poles at that time. The rocks are magnetized in somewhat the 

same way as the nail was by the magnet in your demonstration. What 

Vine and Matthews discovered was a pattern of polar reversal stripes 

on both sides of the ridge. The purpose of this activity is to simulate 

those patterns. 

3. For each group of two or three students, pass out 20 audiotape 

strips, one 3 by 5 card, glue or tape, and a magnet. 

4. Give these instructions: 

a. Tape 6 or 7 strips of audiotape to the card by one end, so they are 

parallel to each other and about 1 cm apart. One end will be loose, as 

shown on the illustration. 

b. Stroke one of the strips with one pole of the magnet. Then stroke 

the next strip with the other pole of the magnet. 

When the magnet is passed over the loose, ends of the tape, the strips 

will move. Their direction will depend on which end of the magnet 

they were stroked with. 

TEACHING CLUES AND CUES 

This activity works best if

the card is held upside 

down with the tape 

hanging down. 

c. Create patterns of magnetism by mixing up the order in which you 

stroke the strips of tape, then give the cards to other groups to 

interpret. 

C. Conclusion 

After they have had a chance to create patterns and share them with 

other groups, ask students if they were able to interpret the other 

groups’ patterns. How did the tape strips record the direction of the 

magnetism? (Magnetic particles are embedded in the tape.) 

This activity was adapted from a workshop on earth science activities 

presented at the Exploratorium in San Francisco, CA.

Be sure all strokes on 

the individual strips are 

in the some direction. Do 

not touch again when 

testing polarity. 

PART TWO 

RECORDS IN THE ROCK

A. Introduction 

Review the structure of the Earth’s interior with the class, drawing on 

Master 2.2a. Remind students that in the last activity they saw how 

patterns of magnetic polarity can be recorded. What Vine and 

Matthews saw, as they explored the Mid-Atlantic Ridge with their 

instruments, was a similar pattern recorded in volcanic rocks. Looking 

at these patterns on one side of the ridge, they noticed that the opposite 

side showed a mirror image of reversals. Their next step was to collect 

rock samples from the sea floor and determine the age of the rocks, to 

find out when the volcanoes that formed the rocks erupted. They 

discovered not only that the patterns of ages were mirrored on the two 

sides, but also that the rocks on both sides were progressively older as 

they moved away from the ridge. The next activity will help students 

understand the process Vine and Matthews followed. 

AGU / FEMA 48 S EISMIC S LEUTHS
B. Procedure 

l. Give each group a copy of Master 2.2c, Reading the Patterns, and a 

pair of scissors. Give these instructions: 

a. Cut the reversal pattern off the bottom of the sheet and trim away 

everything outside the dotted outline. 

b. Cut the reversal pattern along the dashed horizontal line in the 

center to form two strips. Place the two strips together with the 

patterned bands facing in, making sure that the arrows on both strips 

face the same way. Tape ends together. 

c. Insert the scissors at one of the black dots on the map and carefully 

cut a slit along the axis of the mid-ocean ridge, following the broken 

line between the two dots. Insert the open end of the folded reversal 

pattern into the slit from underneath, holding onto the stub, and 

carefully pull the first several centimeters of paper through (up to the 

first dark line). Crease the strip along the dark line so the first pattern 

is showing, bend it flush with the paper on one side of the ridge, and 

label it with a 1 in red ink. Do the same thing on the other side of the 

ridge. 

Tell students that this represents a volcanic eruption during which the 

rocks adopt the magnetic field of the Earth at that time. Then, 

announce that a reversal of the poles has occurred. 

TEACHING CLUES AND CUES d. Pull up the second pattern on the strip, bend it over, and label it 2. 

Repeat with the other side. Continue this process until all the patterns 

have been pulled up and labeled. 

2. When all the bands have been labeled, ask students: 

There should be nine 

bands on each side of 

the ridge. 

QWhat does each fold of paper represent as it is pulled up from 

below? (new rock being erupted from inside the Earth by volcanic 

action) 

QWhich pattern represents the oldest volcanic rock? (Number 1) 

QIs the pattern of the reversals and the ages mirrored on the two sides 

of the ridge? (Yes.) 

QWhy do the pattern bands vary in width? (Their width is determined by how much volcanic activity occurred before the reversal 

and how long the reversal of polarity lasted.) 

QCan you tell which way the poles were oriented during any given 

age on your model? (Yes.) 

C. Conclusion 

Conduct a quick drill to be sure students understand how the models 

show what direction the poles were oriented in. Call out a number and 

ask students to answer with a direction. Go on until students can 

respond rapidly. 

AGU / FEMA 49 S EISMIC S LEUTHS
AGU / FEMA 50 S EISMIC S LEUTHS

TEACHING CLUES AND CUES 

To demonstrate paleomagnetic alignment, 

make large blowups of 

the South American and 

PART THREE 

MAPPING PREHISTORY

A. Introduction 

Tell students that in the last activity they modeled the creation of new 

ocean floor at a spreading mid-ocean ridge. Project the transparency of

Master 2.2b and review the section of Master 2.2a entitled Three 

Kinds of Plate Movement, Four Kinds of Boundaries, and discuss. 

Then discuss the driving mechanism for plate tectonics, so students 

understand some of the complicated forces and that scientists are still 

exploring how these forces work. Tell the class that in this last activity 

they will look at one more line of evidence that the continents 

African continents, or draw their 

outlines on the overhead. Demonstrate the process of alignment and 

distance measurements. 

Be sure to pass out two 

copies of Master 2.2d to 

each group. 

have been moving. Review the process of magnetism and how rocks 

pick up the polar orientation during their formation. Explain that 

sensitive instruments called magnetometers can analyze samples of 

rock to discover where the north pole was located during their 

formation. In this next activity, students will use magnetic data 

collected from several different locations to establish plate motions. 

Make sure that the grid 

north line remains 

parallel to the longitude 

lines while you complete 

step 2.b. 

B. Procedure

1. To each small group, pass out scissors, tape, a ruler, two copies of 

Master 2.2d, Continental Pieces, and one each of Master 2.2e, World 

Map Grid, and Master 2.2f, World Map Grid, 120 MYA. Point out 

that there are two north arrows on each of the continental pieces. The 

N stands for north today and the PN stands for paleonorth, or the 

approximate location of the north pole 120 million years ago (MYA). 

The line that lies across the arrow, labeled G, represents grid north, 

and should always line up so it is parallel to longitude (see example on 

Master 2.2e, World Map Grid.) The numbers in the tables on the grid 

masters tell the distance to the north pole from the tip of the arrow 

point at the time that sample was collected. 

2. Give these instructions: 

a. Cut out the continents on one copy of Master 2.2d along the dotted 

continental outlines. 

b. To place the continents on Master 2.2e, World Map Grid, begin 

with any continent. Place the ruler alongside the present day north 

arrow line (N) on the continent to align it with the intersection of the 

Prime Meridian (O) and the north edge of the map. Next, align the 

grid north line (G) so it is parallel to the nearest longitude. When both 

arrows are aligned, measure the distance from the pole to the point 

where the two arrows cross. Tape the continent in place. 

c. Repeat the process until all the continents are in place. This creates 

a map of the world as it appears today. 

d. Now repeat the process with a new copy of Master 2.2d, 

Continental Pieces, and a copy of Master 2.2f, World Map Grid l20 

MYA, this time lining up the PN arrows. This creates a map of the 

world as it may have appeared 120 million years ago. 
TEACHING CLUES AND CUES 

You may want to project 

some of the students’ 

completed maps during 

this discussion. 

3. When they have completed both tasks, ask students if they could tell 

which continent moved the most. (India) Point out that the continents 

do not fit together perfectly and ask them for some possible reasons. 

(Students may suggest that the scale could be wrong, the drawings 

may not be quite accurate, or our measurements may be inaccurate.) 

Let students discuss the possibilities. If necessary, ask if they think the 

continents have always had the same outline as they do today. (No. 

The sliding, colliding, and converging movement of the plates has 

added new material in some places and worn the edges away in others. 

Point out western North America and the place where India collided 

with Asia to form the Himalayas.) 

If a wall chart or map of the oceans is available, point out the continental shelves. Explain that geologically each continent extends to the 

edge of its continental shelf. Does the jigsaw puzzle fit together better 

if the edges of the shelves are used as continental boundaries? (Yes.)

C. Conclusion TEACHING CLUES AND CUES 

Review the steps in using magnetism to find the ancient location of the

continents. Point out to students that this evidence was not available 

during Wegener’s time. In this series of activities they have 

experienced some of the ways scientists established the theory of plate 

tectonics. Ask: 

Students will learn more 

about Alfred Wegener in 

the next unit, in lesson 

3.2. 

Q If this information had been available, would it have helped 

Wegener’s case? (Yes.) 

Q How does the last map differ from a map of today? (Discuss.) 

Q At the rate of drift (5 to 15 cm, or 2-7 inches in a year), about how 

long would it take today’s continents to join into one 

supercontinent? (Answers will vary.) 

ADAPTATIONS AND EXTENSIONS 

1. Challenge students to find out how magnetometers work and how 

scientists use them, then report to the class. 

2. On a map of the Pacific Ocean floor, locate the Hawaiian Islands 

and the chain of islands that forms the Emperor Seamounts. Note the 

sharp bend in the line of seamounts. Ask students: 

Q What could have caused the bend? (a change in the direction of 

plate movement) 

Q What does this bend, and the long pattern of reversals illustrated in 

the earlier activities, indicate about the possibility of the Pacific 

Ocean closing? (With plates constantly changing directions, it may 

not close.) 

3. Scientific American published a series of articles on plate tectonics 

in the late 1960s which were published as a collection in 1970 (see 

Wilson, unit resources). Provide students with copies and ask them to 

prepare a report to the class on the evolution of the theory. 

AGU / FEMA 51 S EISMIC S LEUTHS
4. Ask volunteers to compare and contrast continental drift, plate 

tectonics, and sea floor spreading, or to show the relationships among 

plate boundaries, earthquakes, and volcanoes. 

AGU / FEMA 52 S EISMIC S LEUTHS

5. Invite students to build models to demonstrate the four types of 

plate boundaries. 

6. A group of students could create giant cardboard models of the 

continental pieces by enlarging them to scale. They or another group 

could perform a Drift Dance, moving in various patterns until the 

pieces lined up more or less as they are today. 

7. Ask the class: If earthquakes are only supposed to happen in the 

vicinity of plate boundaries, why did the 1811 and 1812 New Madrid, 

Missouri, earthquakes occur? (New Madrid is located on a failed rift 

zone that tried to split North America apart.) Was it an isolated occurrence, or could the same thing happen in other such areas? (There may 

be other such rift zones that have not yet been discovered.) V
AGU / FEMA 53 S EISMIC S LEUTHS
MASTER PAGE Tectonics Background 

AGU / FEMA 54 S EISMIC S LEUTHS

2.2a 

To understand why earthquakes happen, we need to understand two basic facts about the planet we live on: that it 

is made up of layers, and that its surface is broken into irregular pieces called plates. Much of what we know 

about the composition of Earth has been learned by studying how earthquake waves travel in and through it. 

Earth’s Layers 

Just for a moment, imagine the Earth as if it were a hard-boiled egg. It has a thin crust (the shell); a thick middle 

layer, or mantle (the white); and a core (the yolk). The crust and the uppermost portion of the mantle together 

form the lithosphere. The plates are called lithospheric plates because they belong to this region. Scientists divide 

the mantle into zones and the core into an inner and outer core. (See Master 2.2b.) 

Crust and Lithosphere 

Earth’s crust varies in thickness from about 30 km to between 70 and 80 km on the continents to only 6 km on the 

ocean floor. Even at its thickest point, the crust is not nearly as thick in relation to the whole bulk of the Earth as 

the shell of an egg is in relation to the egg. Remember that the crust is 70-80 km thick at its thickest point, and the 

radius of the Earth is about 6,371 km. 

The oldest rocks of the crust found so far have been dated by radioactive decay (isotopic dating) at about 4 billion 

years. Earth scientists assume that the Earth was much hotter billions of years ago than it is today, and that the 

lithosphere (crust plus upper mantle) broke into plates as it cooled and hardened. 

The lithosphere extends to an average depth of about 100 km. It is deepest under the continents and shallowest at 

the mid-ocean ridges. 

Mantle

The mantle contains several zones, or layers with different properties. Its upper portion is a region with a plastic, 

semisolid consistency, called the asthenosphere. The thickness of the asthenosphere is still a matter of debate. 

Estimates of the distance to the base of the asthenosphere range from about 200 km to 700 km. The mantle 

accounts for approximately 67% of Earth’s mass. Information from earthquake waves indicates that this region 

generally behaves as a plastic; that is, it will bend and flow in response to pressure. Temperature and pressure 

continue to increase as we move through the mesosphere to approach the core, at a depth of about 2,890 km. 

Core

Both layers of the care are thought to be composed primarily of iron, with lesser amounts of nickel and possibly 

silicon, sulfur, or oxygen. Scientists have measured the velocity of earthquake waves passing through the core, 

and reason that such movement would be possible through materials with the physical properties of these 

elements. The liquid outer core, which might be compared to the outer two-thirds of an egg’s yolk, reaches from a 

depth of about 2,890 km to 5,150 km. The solid inner core goes the rest of the way to the center of the Earth. 

Earth’s core is very hot. Its high temperatures are due to the tremendous pressure of the layers above it, heat 

generated by the impact of other bodies during the formation of the planet, and radioactive decay. Evidence 

collected from mines and deep wells shows that the average increase in temperature is about 1°C for every 40 

meters of depth. If this rate held constant to the center of the Earth, theoretically, the temperature of the core 

would be about 150,000°C. According to the evidence we have, however, the actual temperature is between 3,000 

and 4,000°C at the core-mantle boundary, and about 5,000°C at the boundary of the outer and inner cores—

roughly the same temperature as the surface of the Sun! 

Earth’s Plates 

Most earthquakes and volcanoes are associated with large-scale movements of Earth’s plates, and occur at the 

boundaries between plates. There are 12 major plates and a number of smaller ones. The plates are named after 

continents (the North American Plate), oceans (the Pacific Plate), and geographic areas (the Arabian Plate). 
MASTER PAGE 

The plates are in very slow but constant motion, so that seen from above by a patient observer, Earth’s surface 

might look like a slowly moving spherical jigsaw puzzle. The plates move at rates of 5 to 15 cm (2-7 inches) in a 

year—about as fast as our fingernails grow. On a human scale, this is a rate of movement that only the most 

sophisticated instruments can detect, but on the scale of geological time, it is a dizzying speed. The oldest rocks in 

the crust, formed 3.8 billion years ago, could have traveled around the Earth 14 times at this rate. 

Three Kinds of Plate Movement, Four Kinds of Boundaries 

Plate movement is generally one of three kinds: spreading, colliding, or sliding. Earthquakes can accompany all 

A. B. 

C. 

three kinds of movement, but 

the most forceful quakes 

generally result from colliding 

and sliding movements. 

When plates are spreading, or 

separating from each other, 

earth scientists call their movement divergent. The type of 

boundary that results (A) is a 

ridge, like the Mid-Atlantic 

ridge system. 

When plates are colliding, or 

pushing against each other, 

scientists call the movement 

convergent. If an oceanic plate 

converges with a continental 

plate or another oceanic plate, 

the oceanic plate is forced down 

into the mantle, creating an 

ocean trench (B). The Alaskan 

trench and the Aleutian Islands 

were formed in this way; so 

D. 

were the Andes Mountains. If two continental plates converge, neither will be forced into the mantle. Instead, 

their edges will crumple and a large mountain chain may result (C). The Himalayas arose when India collided 

with Asia. 

Movement in which plates slide past each other is called lateral (or transform) plate movement (D). This kind of 

movement is occurring along the San Andreas Fault in California. 

AGU / FEMA 55 S EISMIC S LEUTHS
MASTER PAGE 

Continental Drift: 1910 to 1960 

The theory of continental drift originated early in this century, but it did not gain general acceptance until the late 

1960s. Between 1910 and 1912, the German meteorologist, geophysicist, and explorer Alfred L. Wegener 

formulated the theory called continental drift. He collected evidence from the rocks, fossils, and climatic records 

of several continents to show that they had once been joined together. Wegener knew little about the oceanic 

crust, which had not yet been explored, and thought that the continents merely moved horizontally, plowing 

through the oceanic crust. 

Plate Tectonics: 1960 to the Present

In the early 1960s, British geophysicists Fred Vine and Drummond Matthews used magnetic data to show that the 

ocean floor is spreading apart at the mid-ocean ridges. As they shared the evidence for the process they called 

sea-floor spreading, scientists began to realize that the continents were also moving. By 1968, a new explanation 

for the dynamics of Earth’s surface had been created, combining Wegener’s hypothesis with evidence from the 

ocean floor. Scientists call it the theory of plate tectonics. 

AGU / FEMA 56 S EISMIC S LEUTHS
MASTER PAGE 

The Mechanism of Plate Tectonics

Although the theory of plate tectonics is generally accepted, no one completely understands how the process 

works. Wegener thought that centrifugal force, caused by the rotation of the Earth, and tidal forces caused 

continental drift. Modern scientists have rejected this theory and replaced it with several others. Three 

mechanisms called convection, ridge push, and slab pull may play a role. 

Convection Currents 

Convection currents are systems of heat exchange that operate in the mantle as it is heated by the core. The 

mantle’s plastic-like material moves upward as it is heated, and sinks when it cools. You can see this kind of 

movement if you boil water in a clear glass pot. Even though the heat on the stove is constant, the water on the 

bottom of the pot is the hottest. As it heats, it becomes less dense and rises, while relatively cooler water from the 

top of the pot takes its place on the bottom. This continuous exchange creates convection currents in the water. 

According to this theory, convective movement acts as a drag on the underside of the plates. As mantle material 

moves in large convection cells, the plates are rafted along the top of the cells, being pulled apart where the cell 

rises and colliding where it sinks. 

Ridge Push 

The ridge-push mechanism derives from the bulging of the undersea ridge crest as the oceanic lithosphere below 

it expands. The lithosphere expands because it is heated by mantle material pushing upward from below. As the 

lithosphere is pushed up at the ridge, a large portion of a plate may come to rest on an inclined plane. Gravity will 

cause this portion to slide down the inclined plane and push on the rest of the plate. 

Slab Pull 

Once this slab of oceanic lithosphere moves away from the ridge crest (and from the heat that is rising at the 

ridge), it will cool and contract, increasing in density. It will also thicken as underlying mantle material cools and 

attaches itself to the bottom of the slab. Eventually, the slab of lithosphere becomes denser than the underlying 

asthenosphere and sinks into the mantle. As it sinks, it pulls the rest of the plate along with it. At about 200 to 300 

km, the difference in density between the descending slab and the mantle is at its greatest, so the slab pull force is 

also at its greatest. Below this point, the mantle material becomes stronger and the resistance to sinking also 

becomes stronger. 

A Natural Cycle 

One result of all this slow, steady motion is the gradual opening and closing of ocean basins. As tectonic 

processes rearrange the surface of the planet, shifting lands and seas over millions of years, they also cause 

earthquakes. Now, and for the foreseeable future, human beings have no way to affect these mighty tectonic 

processes. By understanding them, however, we can learn to conduct our own lives in ways that minimize our risk 

from any disturbances they may cause.

AGU / FEMA 57 S EISMIC S LEUTHS
AGU / FEMA 58 S EISMIC S LEUTHS
MASTER PAGE Earth Cross Section 

AGU / FEMA 59 S EISMIC S LEUTHS

2.2b 
AGU / FEMA 60 S EISMIC S LEUTHS
2.2c MASTER PAGE Reading the Patterns 

AGU / FEMA 61 S EISMIC S LEUTHS
AGU / FEMA 62 S EISMIC S LEUTHS
2.2d MASTER PAGE Continental Pieces 

AGU / FEMA 63 S EISMIC S LEUTHS
AGU / FEMA 64 S EISMIC S LEUTHS
2.2e MASTER PAGE World Map Grid 

AGU / FEMA 65 S EISMIC S LEUTHS
2.2e MASTER PAGE World Map Grid (key) 

AGU / FEMA 66 S EISMIC S LEUTHS
2.2f MASTER PAGE World Map Grid, 120 MYA 

AGU / FEMA 67 S EISMIC S LEUTHS
2.2f MASTER PAGE World Map Grid, 120 MYA (key) 

AGU / FEMA 68 S EISMIC S LEUTHS
2.3 

 in Geologic 

Time 

VOCABULARY

Index fossil: a fossil 

that, because its approximate date is known, 

allows scientists to 

determine the age of 

ACTIVITY ONE 

TWENTY CENTURIES

RATIONALE 

Students have a difficult time comprehending how short the span of 

human history is in relation to Earth’s geological history. This lesson 

sets the stage for paleoseismology by providing a context in geological 

time. 

FOCUS QUESTIONS 

If no earthquakes have been recorded in my area since it was settled, 

does that mean earthquakes never happen here? 

OBJECTIVES 

Students will: 

Students will compare the time period of their own lives and that of 

human history to the age of the Earth and events in Earth’s history. 

MATERIALS

Q Student copies of Master 2.3a, Centuries Worksheet 

Q Twelve 500-sheet reams (one case) of standard copier paper 

Q Student copies of Master 2.3b, Selected Events in Human History 

Q Student copies of Master 2.3c, Earth History Events 

Q Scissors 

age of the rock in which it is 

imbedded.

Radiometric dating: the process of 

using natural radioactivity to 

determine the age of rocks. 

Strata (s. stratum): layers of rock or 

other materials formed at different 

periods in geologic time.

PROCEDURE 

Teacher Preparation 

1. Obtain 12 reams of standard-size paper and stack them on a desk 

where they will be visible to all students. Unwrap only the top ream. 

On each of the lower reams, cut a strip 7 to 10 cm wide from the side 

of each wrapper so the paper shows through. The results should be a 

column of exposed paper edges 11 reams high. Stack the unwrapped 

twelfth ream neatly on top, and place a copy of the Centuries 

Worksheet on top of the stack. 

AGU / FEMA 67 S EISMIC S LEUTHS
2. Make a copy of Master 2.3c, Earth History Events, and cut it into 

strips along the dashed lines. 

A. Introduction 

Ask the students to tell you what they mean when they say that 

something happened “a long time ago.” (Answers will range from a 

few months to centuries and beyond.) Ask students if it was “a long 

time ago” that dinosaurs became extinct, and our earliest human 

ancestors first appeared. Then ask them to guess the order in which 

these events occurred. Record their guesses without comment. 

Emphasize that scientists seek proof of how long ago different events 

occurred by studying things that record the passage of long periods of 

time, such as the layers in rocks (strata) and index fossils. Index fossils 

represent species that existed only during specific time periods, so their 

presence is an index to the age of the rocks. Radiometric dating 

techniques can also reveal how long ago rocks were formed. The 

dating of events that occurred a long time ago and the sequence in 

which they occurred are among the puzzles scientists must solve. We 

are constantly adding to our knowledge of Earth history. 

B. Lesson Development 

1. Distribute copies of the Centuries Worksheet (Master 2.3a). Holding 

up the copy you placed on top of the paper stack, tell the students that 

the stack is 12 reams high, and that every single page in it stands for 

the same length of time. Explain that every dot on the sheet stands for 

one year. The first dot on the top line represents this year. Each dot 

after that one is a previous year. The entire sheet contains 2,000 dots. 

Ask the students to circle the dot representing the year in which they 

were born. 

2. Distribute copies of Master 2.3b, Selected Events in Human History. 

With these sheets and their Centuries Worksheets in front of them, 

have students place the number of each event on Master 2.3b on or 

near the dot that represents its year. 

3. Tell the class that geologic time calls for a different scale than 

historical time. From now on, one dot equals one hundred years. Each 

sheet of paper in the 12-ream stack now represents 200,000 years. The 

farther down the stack a sheet is, the farther back in history the time it 

represents. Ask the students to determine how far down the stack a 

sheet representing one million years ago is located. (It will be five 

sheets down.) 

4. Ask students how many dots there would be in a ream of 500 sheets 

of paper if each sheet had 2,000 dots. (1,000,000 dots). If each dot 

represents 100 years, how many years would one ream of sheets 

represent? (100 years x 1,000,000 dots per ream = 100,000,000 years.) 

5. Distribute the strips of paper cut from Master 2.3c, having each 

student choose one. Give students these directions: 

a. Calculate how many years an inch of paper represents. Look at your 

paper strip and decide if the event it names will fit within the span of 

years represented by the reams of paper (1.2 billion years). 

AGU / FEMA 68 S EISMIC S LEUTHS
b. If it does, calculate how far down the paper stack to place your 

individual marker, then come forward to place it at the correct depth. 

c. If it does not, use the math we have already done to calculate how 

much more paper would be needed. Share your findings with the class. 

6. Elicit ideas from the class on the age of the Earth. (The answer, 

about 4.54 billion years, is on Master 2.3c.) Ask: How many reams of 

paper like the ones in the front of the classroom would it take to 

represent that many years? (46 reams) 

C. Conclusion 

Ask the class: Now that you have an idea of the age of the Earth, 

would you describe the human race as young or old? (relatively 

young) Which occurred more recently, the extinction of the dinosaurs 

or the appearance of human beings? (the appearance of humans) 

Compare these facts with the students’ earlier guesses. Emphasize that 

terms like young and old, long ago and recent can have very different 

meanings in different contexts. Because an event such as an 

earthquake has not taken place in historical time does not mean it is 

impossible, given the great sweep or geological time. 

TEACHING CLUES AND CUES 

The two parts of this 

activity use the same 

materials and take 

approximately the same 

ACTIVITY TWO 

PALEOSEISMOLOGY, OR READING THE CLUES

RATIONALE 

By using models, students will learn how geologists apply present 

knowledge to understand seismic history. 

FOCUS QUESTIONS 

How do we know about earthquakes that happened long ago? 

OBJECTIVES 

Students will: 

1. State and explain several basic geologic principles. 

2. Model the procedure geologists use to determine earthquake 

recurrence intervals. 

length of time. It may be convenient 

to do them in sequence. Alternatively, you may want to have half the 

class do the first activity and the rest 

do the second. 

MATERIALS 

Q Transparencies made from Master 2.3d, Sag Pond, 1830 to 1994 

Q Overhead projector 

Q Newspapers for covering desks 

Q Play clay or modeling clay, in red, blue, yellow, and white 

Q Student copies of Master 2.3e, Sag Pond Template 

Q 15-cm (6-in) lengths of dowel or other small cylinders for rolling 

play dough (optional) 

Q Knives for cutting the clay (Plastic picnic knives will do.) 

AGU / FEMA 69 S EISMIC S LEUTHS
VOCABULARY 

Paleoseismology: the 

study of ancient 

earthquakes. 

Q Transparencies made from Master 2.3f, Ditch Creek, 1830 to 1994 

Q Student copies of Master 2.3g, Ditch Creek Template 

PART ONE 

SAG POND

PROCEDURE 

A. Introduction 

Ask students: Have your parents or grandparents experienced an 

earthquake in their lifetime? Explain: Geologists assume that the 

earthquakes we observe today are similar to those that happened 50 

years ago, 100 years ago, and even before human beings recorded 

history. Their impact may be different because of differences in 

human population patterns, but geologic processes and the natural 

principles that govern them have operated in essentially the same way 

throughout geological time. This assumption is expressed in the 

principle of uniformitarianism. By studying the traces of recurring 

earthquakes, those that have happened numerous times in the same 

area, we can speculate about the history of very old earthquake events 

and even make general predictions about the future. Introduce the 

principle of superposition and the principle of cross-cutting 

relationships. The activity that follows uses a generalized model of a 

strike-slip fault to illustrate these principles. 

B. Lesson Development 

1. Project the first transparency made from Master 2.3d, Sag Pond, 

1830 to 1993. Tell students that the diagrams they see show the effect 

of faulting in successive earthquakes. Because faulting causes surface 

dislocations, certain types of faulting will form hills and valleys in the 

Earth’s surface. With strike-slip faulting, if movement occurs as 

shown by the arrows, the following topography can be created: 

Peat: a deposit of semicarbonized 

plant remains in a water-saturated 

environment. Peat is an early stage 

in the development of coal. 

Principle of crosscutting 

relationships: the principle stating 

that a rock is always younger than 

any other rock across which it cuts. 

Earthquake faulting illustrates this 

principle: Faults are always younger 

than the rocks they cut. 

Principle of superposition: the 

principle upon which all geologic 

chronology is based, stating that in 

any sequence of sedimentary layers 

that has not been overturned or 

faulted, each layer is younger than 

the one beneath, but older than the 

one above it. 

Principle of uniformitarianism: the 

fundamental principle stating that 

geologic processes have operated in 

essentially the same way throughout 

geological time. 

Recurrence interval: the actual or 

estimated length of time between 

two earthquakes in the some 

location. 

Sag pond: a small body of water 

occupying an enclosed depression 

formed by strike-slip fault movement. 

Strike-slip faulting: faulting in which 

movement is horizontal. 

TEACHING CLUES 

AND CUES 

If students have 

questions at this point, 

tell them that the activity 

that follows may answer 

them. Any questions that are not 

answered by the activity can be dealt Right Lateral Strike-Slip Fault with in the concluding discussion. 

X = area where ground 

is being pulled apart 

or extended, forming a sagpond.

Left Lateral Strike-Slip Fault 

Y = area where ground 

is being squeezed or compressed, forming a 

hill or ridge.

 

AGU / FEMA 70 S EISMIC S LEUTHS
2. As you point to each of the figures, 1 through 6, read the 

accompanying text aloud to the class. 

3. Divide the class into working groups of three to five students each. 

Distribute paper for covering desks, clay, knives, rollers (if available), 

and one copy of Master 2.3e, Sag Pond Template, to each group. Give 

these directions: 

a. Pat or roll two clay patties, one white and one red, to a thickness of 

about 1 cm (.3 in.). Using the template provided, trim the patties to fit 

within the confines of the circle marked on the grid, then remove them. 

b. Now make two sag pond peat deposits, one white and one blue, each 

0.5 cm thick and sized according to the small sag pond template at the 

upper left of the grid. 

c. Place the large white layer on the grid template between A-B and 

C-D as outlined. Place the blue clay sag pond deposit on top of this first 

layer, aligning the long axis of the sag pond layer with fault line E-F, 

and centering it between A-B and C-D. Out both layers along the fault 

line E-F. Lift the A-B side and raise it to the position marked Offset 

Line. 

d. Place the red layer of clay over the offset layers and center a second 

sag pond deposit (the white one), as in the stop above. Cut (or trench, 

as geologists say) all the clay patties along line A-D. Carefully separate 

the sides so you have a good cross-section view and draw a cross 

section of each side. Compare the layers on the two sides of the fault 

A-D. 

C. Conclusion 

Build a class discussion around these questions: 

Q How is the principle of superposition applied in this activity? 

Q How is the principle of crosscutting relationships applied in this 

activity? 

Q How is the principle of uniformitarianism applied in this activity? 

Q What does the difference in thickness and spacing of the peat layers on 

the two sides of the fault indicate? (that the terrain has been disturbed) 

Q In what year do we know an earthquake occurred on this fault? (1857) 

PART TWO 

DITCH CREEK

PROCEDURE 

A. Introduction 

Tell students: By using age-dating methods on peat deposits and very 

old stream channels, geologists can determine earthquake recurrence 

intervals dating back several thousands of years. The shorter its recurrence interval, the more likely an area is to experience an earthquake in 

your lifetime. This activity is another illustration of the principles you 

saw in the last one. Like the previous activity, it is based on a 

generalized model of a strike-slip fault. 

AGU / FEMA 71 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

Remind students that 

arrows placed on fault 

diagrams show the 

relative direction of the 

motion. 

You may want to cover 

the copy at the bottom of 

the master (Figure 2, 

p. 85) while you ask 

B. Lesson Development 

1. Project the first transparency made from Master 2.3f, Ditch Creek. 

Tell students that the diagrams they see show the effect of faulting in 

successive earthquakes. As you point to each of the figures, 1 through 

5, read the accompanying text aloud to the class. 

2. Divide the class into working groups of three to five students each. 

Distribute paper for covering desks, clay, knives, rollers (if available), 

and one copy of Master 2.3g, Ditch Creek Template, to each group. 

Give these directions: 

a. Make three layers of clay, one white, one yellow, and one red, 

patting or rolling the clay to a thickness of about 1 cm (1/3 in.) and 

trimming it to fit within the confines of Area 1 on the grid. Place the 

white layer on the Area 1 part of the grid and remove the others. Make 

a pencil-thick string of blue clay and lay it along the line marked on 

the grid as Stream Line, running the length of the first layer. With the 

knife, cut along the E-F fault line marked on the grid, which is 

perpendicular to the stream. Now offset the C-D section of the model, 

moving it to the position marked 1857 on the grid. This offset 

represents the movement along the fault of 1857. 

b. Now place the yellow layer on top of the white layer and the offset 

stream. Be sure to place this second layer within the grid marks. Make 

another pencil-thick stream out of blue clay and place it on the same 

stream line indicated on the grid. Cut the layers again along the same 

fault line as in the previous step. Offset the C-D section to the position 

marked 1906. 

c. Repeat this one more time with the red clay layer and one additional 

blue streamline. 

C. Conclusion 

Build a class discussion around these questions: 

students to describe what they think 

has happened to produce the new 

picture. 

QHow is the principle of superposition applied in this activity? 

QHow is the principle of crosscutting relationships applied in this 

activity? 

QHow is the principle of uniformitarianism applied in this activity? 

QWould you build your home in 1994 or later near this fault? 

ADAPTATIONS AND EXTENSIONS 

Provide a small-scale map of a seismic area and ask students to locate 

other streams along fault lines and identify offset stream channels. For 

example, on a map of the Grand Canyon, locate Bright Angel Canyon 

and point out the place where it meets the Colorado River. Ask: What 

caused the Bright Angel Creek to cut a canyon where it did? (The 

Bright Angel fault caused a weak place in the rock for the water to 

erode.) V

AGU / FEMA 72 S EISMIC S LEUTHS
2.3a MASTER PAGE Centuries Worksheet

Name ___________________________________________________________ Date _____________________ 

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

AGU / FEMA 73 S EISMIC S LEUTHS
AGU / FEMA 74 S EISMIC S LEUTHS
MASTER PAGE 

Selected Events in Human 

History

2.3b 

1. _____—My great grandmother is born. (Estimate.) 

2. 1776—U.S. Congress adopts the Declaration of Independence. 

3. 1936—Inge Lehmann demonstrates the presence of an inner core. 

4. 1492—Columbus reaches the Americas. 

5. 1909—Andrija Mohorovicic discovers discontinuity at 

crust/mantle boundary. 

6. 1989—Loma Prieta quake rocks World Series fans. 

7. 1811/1812—New Madrid quakes, greatest ever in continental 

U.S., estimated at over 8.0 on the Richter scale. 

8. 1755—Offshore earthquake near Lisbon, Portugal. Earthquake, 

40-foot tsunami, and fires kill 60,000 people. 

9. 132—Chinese scholar Chang Heng invents seismoscope to detect 

earthquakes. 

10. 1556—The most disastrous earthquake on record, at Shen-Shu, 

China, kills 830,000 people. 

11. 1889—First record of a distant earthquake was received at 

Potsdam, Germany. 

AGU / FEMA 75 S EISMIC S LEUTHS
AGU / FEMA 76 S EISMIC S LEUTHS
MASTER PAGE Earth History Events 2.3c 

1. Earth formed—approximately 4.54 billion years ago 

2. North and South America joined by the closing of the Isthmus of Panama—approximately 2,800,000 years ago 

3. Last trilobites died out—approximately 225 million years ago 

4. Earliest known humanoid (our early ancestor) fossils deposited—approximately 2 million years ago 

5. Earliest known animal fossils (jellyfish-like organisms) deposited—approximately 1.2 billion years ago 

6. New Madrid rift zone opened—approximately 500 million years ago 

7. Earliest known reptile fossils deposited—approximately 290 million years ago 

8. Earliest known bird fossils deposited—approximately 160 million years ago 

9. Earliest known mammal fossils deposited—approximately 200 million years ago 

10. Earliest known flowering plant fossils deposited—approximately 135 million years ago 

11. Earliest known trilobite fossils deposited—approximately 600 million years ago 

12. Present day Appalachian Mountains formed—approximately 250 million years ago 

13. Rocky Mountains formed—approximately 70 million years ago 

14. Mass extinction of dinosaurs and other forms of life occurred—approximately 65 million years ago 

15. Breakup of Pangaea began—approximately 180 million years ago 

16. Earliest known fossils of land animals deposited—approximately 390 million years ago 

17. Last lee Age ended—approximately 10,000 years ago 

18. Oldest known rock on Earth formed in southwest Greenland—approximately 3.2 billion years ago 

19. Himalayas begin forming as India joined Asian continent—approximately 30 million years ago 

20. Formation of iron, copper, and nickel ores—1 billion years ago 

21. Much of continental land masses underwater—330 million years ago 

22. Active volcanoes in New England—210 million years ago 

23. Earliest microfossils formed in South African chert—3.2 billion years ago 

24. Algal stromatolites formed in Rhodesian limestones—3 billion years ago 

AGU / FEMA 77 S EISMIC S LEUTHS
MASTER PAGE Earth History Events (key) 2.3c 

Reams (and/or) Pages Total Pages 

1. 46 — 23,000 

2. — 14 14 

3. 2 125 1,125 

4. — 10 10 

5. 12 — 6,000 

6. 5 — 2,500 

7. 2 450 1,450 

8. 1 300 800 

9. 2 — 1,000 

10. 1 175 675 

11. 6 — 3,000 

12. 2 250 1,250 

13. — 350 350 

14. — 325 325 

15. 1 400 900 

16. 3 450 1,950 

17. — 1 1 

18. 32 — 16,000 

19. — 150 150 

20. 10 — 5,000 

21. 3 150 1,650 

22. 2 50 1,050 

23. 32 — 16,000 

24. 30 — 15,000 

AGU / FEMA 78 S EISMIC S LEUTHS
MASTER PAGE Sag Pond, 1830 to 1994 2.3d 

Right Lateral Strike-Slip Fault Left Lateral Strike-Slip Fault 

Figure 1, Sag pond 

In the left-hand side of Figure 1 (X), there is a place where the ground has pulled apart. The depression caused by 

this “pull-apart” basin is called a sag pond. This is a very narrow, long or elongated pond or basin. Sag ponds are 

generally aligned with the long axis parallel to the faults. In the right-hand drawing, (Y), a ridge is being formed 

by squeezing, or compression. 

Figure 2, Sag pond 1830 

Fault slippage has formed a sag pond, which has filled with water containing reeds, cattails, and algae. These 

organic materials die and accumulate rapidly on the bottom of the sag pond in the form of peat. Peat can 

accumulate as much as several centimeters per year. 

AGU / FEMA 79 S EISMIC S LEUTHS
MASTER PAGE 

Figure 3, Sag pond 1857 

Fault moves, offsetting shorelines of sag pond and organic materials (peat) on bottom. 

Figure 4, Sag pond 1994 

Shortly after the faulting, a new sag pond forms with more reeds, cattails, and algae. Peat continues to 

accumulate. In 1994 the sag pond is pumped dry, and a shallow trench (A-B) is dug with excavation equipment 

perpendicular to the fault. A sketch of one side of the trench is reproduced below (see Figure 5). 

Figure 5, Trench Log 1, 1994

AGU / FEMA 80 S EISMIC S LEUTHS
MASTER PAGE 

Later that same year, a deeper trench is excavated across the same sag pond, and the following trench log is 

obtained: 

Figure 6, Trench Log 2, 1994 

What are your conclusions regarding the pre-1830 seismic history (the paleoseismology) of this fault? (The peat 

layer shows that faulting has taken place. The depth of the layers can be measured, and the distance between the 

layers can be measured.) 

AGU / FEMA 81 S EISMIC S LEUTHS
AGU / FEMA 82 S EISMIC S LEUTHS
MASTER PAGE Sag Pond Template 2.3e 

AGU / FEMA 83 S EISMIC S LEUTHS
AGU / FEMA 84 S EISMIC S LEUTHS
MASTER PAGE Ditch Creek, 1830 to 1994 2.3f 

Figure 1 1830 

A stream (a) flows across a strike-slip fault. 

Figure 2 1857 

An earthquake with movement along the fault in 1857 causes displacement of stream (a) as shown. The amount of

displacement probably represents the amount of offset the earthquake caused. As the years go by, soil and sand 

may bury and cover up parts of the original stream course (b). 

AGU / FEMA 85 S EISMIC S LEUTHS
Figure 3 1906 

Another earthquake with movement along the same fault in 1906 causes further offset of the course of the stream. 

Soil and sand will continue to bury and cover up parts of the 1857 (b), and the 1906 (c) offset. A shallow trench 

(line G-H) cut parallel to and south of the fault in 1994 might show the following relationship (Figure 4) on the 

southern side of the trench: 

SECTION VIEW 

Ground surface 

Figure 4 Trench Log 1, 1994 

The rate of movement and timing of earlier earthquakes can be determined from the age of the sand and gravel 

deposits in the stream channel. 

If a second longer and deeper trench is excavated in the area of trench G-H, the following log might be obtained 

(Figure 5): 

SECTION VIEW 

Figure 5 Trench Log 2, 1994 

AGU / FEMA 86 S EISMIC S LEUTHS
MASTER PAGE Ditch Creek Template 2.3g 

AGU / FEMA 87 S EISMIC S LEUTHS
AGU / FEMA 88 S EISMIC S LEUTHS
2.4 

 Hazards 

ACTIVITY ONE 

LIQUEFACTION: THAT SINKING FEELING

RATIONALE 

Like other earthquake-related phenomena, liquefaction may cause the 

loss of property and even injury or death. This model allows 

instructors and students to observe the effects of liquefaction and the 

phenomenon of sand boils on a small scale. 

FOCUS QUESTIONS 

What happens when a damaging earthquake strikes areas prone to 

liquefaction? 

OBJECTIVES 

Students will: 

1. Construct a model to demonstrate liquefaction. 

2. Distinguish between soil liquefaction and soil saturation. 

3. Assess potential damage to homes, lifelines, and schools. 

TEACHING CLUES AND CUES 

If possible, substitute a 

small, hollow, ceramic 

house, measuring 

approximately 

5 x 5 x 7 cm, for 

MATERIALS 

for the teacher

Q Master 2.4a, Teacher Background Reading: Liquefaction 

Q Master 2.4b, New Madrid Narrative 

for each small group 

Q 226 g (about 8 oz) of well-sorted fine sand [Sandbox sand works well.] 

Q One .25-1 (9 oz) clear plastic cup 

Q One pie plate, diameter 23 cm (9 in.) 

Q 225 ml (5 oz) of water in a pitcher 

Q Sinker or comparable small object weighing at least .06 kg (2 oz) 

Q One 250-ml beaker 

Q Newspapers to cover work surface 

the sinker. These are sold at hobby 

shops for Christmas scenes, and 

can be filled with BBs to add weight. 

AGU / FEMA 89 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

Students may be aware 

that the flooding of the 

Mississippi and Missouri 

Rivers in the summer of 

1993 caused mud boils in some 

places. Explain that these eruptions, 

somewhat similar to sand boils, were 

caused by extreme saturation of 

muddy soils in combination with the 

force of the torrential rains. Mud 

boils, like sand boils, can also be 

caused by earthquakes over 

magnitude 5.0. 

VOCABULARY 

Consolidated: tightly 

packed, composed of 

particles that are not 

easily separated. 

PROCEDURE 

Teacher Preparation 

Read Master 2.4a, Teacher Background Reading: Liquefaction, and 

Master 2.4b, New Madrid Narrative. Decide how you will share this 

information with your students. Students who like to read will find 

New Madrid Narrative delightful. 

Gather enough materials so you can have two students per station. 

Before class, cover work areas with newspapers, set up the stations, 

and practice each activity at least once to be sure everything works. 

A. Introduction 

Tell students that an earthquake with a magnitude of 5.0 or greater 

may cause saturated sand or clay soils to liquefy. During the winter 

of 1811 and 1812, a series of earthquakes affected the central por-tions 

of the United States that we now know as Missouri, Arkansas, 

Kentucky, Illinois, and Tennessee. As the soft sediments along the 

rivers were violently shaken, tremendous volumes of sand were liquefied and ejected onto the Mississippi River flood plain. These sand 

boils, as they are called, are still visible in the rural countryside today. 

Fortunately the area of the earthquakes was not heavily populated in 

1811-12, so loss of life, injuries, and loss of property were minimal. 

During the 1989 World Series in San Francisco, a 7.1 earthquake 

struck the Bay Area. Millions of people viewed firsthand the fires and 

severe damage to buildings in the Marina District. Some of this 

damage occurred because soil liquefaction caused lifelines to rupture 

and buildings to collapse. 

B. Lesson Development 

1. Write the word liquefaction on the board, and ask student to 

identify its root work (liquid). Emphasize that liquefaction does not 

cause an earthquake, but is the result of an earthquake. Liquefaction 

occurs only in highly saturated sand or clay soils. An earthquake with 

a magnitude of 5.0 or greater is usually needed to cause liquefaction. 

Earthquake vibrations cause soil particles to lose contact with each 

other, so the soil takes on the characteristics of a liquid. 

2. Assign a partner to each student and designate a work station for 

each team. Give these directions: 

a. Cut off about 5 mm from the bottom portion of the plastic cup. 

b. Invert the cup and place it in the middle of the pie pan. 

c. Holding the cup firmly, slowly pour the sand into the bottom of the 

cup to a level of 10-20 mm from the top. (One student may hold while 

another pours.) Level the sand with your fingers. Do not shake the cup 

to settle or level the sand.

d. Lightly place the sinker, model house, or other weight onto the 

leveled surface of the sand. 

Ground water: subsurface or 

underground water. 

Lifeline: a service that is vital to the 

life of a community. Major lifelines 

include transportation systems, 

communication systems, water 

supply lines, electric power lines, 

and petroleum or natural gas 

pipelines. 

Liquefaction: the process in which 

a solid (soil) takes on the 

characteristics of a liquid as a result 

of an increase in pore pressure and 

a reduction in stress. 

Sand boil: a forcible ejection of sand 

and water from saturated soil, 

caused by an earthquake or heavy 

flooding. 

Saturated: having absorbed water 

to the point that all the spaces 

between the particles are filled, and 

no more water can enter. 

Unconsolidated: loosely arranged, 

not cemented together, so particles 

separate easily. 

AGU / FEMA 90 S EISMIC S LEUTHS
e. Again holding the cup, slowly pour the entire 225 ml of water into 

the pie pan around the outside of the cup and sand. 

f. Observe what happens and record the time it takes for the soil to 

reach saturation. 

g. Once the soil is saturated, one student win hold the cup firmly in 

place while the other gives the side of the cup several sharp taps to 

simulate earthquake shaking. Observe what happens to the weight. 

C. Conclusion 

Help students to clean up and then initiate the discussion. Ask: If the 

weight in our experiment were an occupied building, and liquefaction 

occurred over a large inhabited area, as it did in the San Francisco Bay 

Area in 1989, what would be the effect on: 

Q People? 

Q Private homes? 

Q Schools? 

Q Buried lifelines (gas, water, electrical, oil, sewage)? 

Q Agricultural lands? 

Q Medical facilities, fire stations, police stations? 

Q Large urban areas (Memphis, San Francisco, Boston)? 

Q Industrial areas? 

Q Materials that had been discarded in old sand boils? (These could 

range from dead cows to old refrigerators to poisonous waste.) 

ADAPTATIONS AND EXTENSIONS 

1. Make sand of various particle sizes and objects of different masses 

available for student experiments. Investigate the degree of 

liquefaction each will exhibit and the effects on the structures that rest 

upon them. (A layer of diatomaceous earth under the sand will bubble 

up when the table is rapped. Try it!) 

2. Invite students to find ways to vary the amount of force they apply 

to the sand and water mix in the model. 

3. Provide an aquarium or plastic gallon jars so students can 

experiment with larger models. Use transparent containers of any 

size—even a plastic sandwich box—for an interesting side view. 

4. Bury objects in the sand and observe the results. 

5. Develop models of overhead power lines, pipelines, sewage lines, 

light posts, and highways, and observe how liquefaction affects them. 

6. Challenge students with this question: If a building has already been 

constructed on soil that has a potential to liquefy, what can be done to 

reduce the likelihood of damage? Invite them to design and test model 

structures that would reduce structural damage during liquefaction. 

AGU / FEMA 91 S EISMIC S LEUTHS
ACTIVITY TWO 

LANDSLIDES: SLIP-SLIDING AWAY

RATIONALE 

Earthquakes dramatically increase the potential for landslides in areas 

where landslides are common, such as those where sedimentary rocks 

lie just under the soil. Structures on cliffs and ridges need to be 

designed to the highest earthquake standards, and should be fully 

insured. 

FOCUS QUESTIONS 

How can an earthquake trigger a landslide? 

What factors affect the probability of an earthquake-related landslide? 

OBJECTIVES 

Students will: 

1. Construct a model to simulate an earthquake-related landslide. 

2. Investigate the variables that affect an earthquake-related landslide, 

such as the strength of the slope materials, the steepness of the slope, 

and the intensity of ground shaking. 

3. Explain why the steepness of a slope determines how the force of 

gravity acts on an area of ground and how it is related to frictional 

forces. 

MATERIALS

for the teacher

Q Slides or photos of landslide damage (in your geographic area, if 

available) 

Q Slide projector and screen or blank wall space (optional) 

Q Pasteboard or cardboard arrows in three colors, cut to the correct 

lengths to illustrate the 30° angle (optional) 

for each small group TEACHING CLUES AND CUES

Q A pine board, approx. 2.5 cm x 25 cm x 1.0 m (1 in. x 10 in. x 3 ft.) 

Q A meter stick 

Q Two plastic dishes, approx. 19 cm in radius, with sides 3.5 cm high 

The width of the board 

can vary, but it must be 

1 m long. 

Q Enough dry sand to fill the two dishes 

Q 500 ml of water in a beaker or other suitable container 

Q Newspapers to cover work surfaces 

Q A sensitive bathroom scale that can register weights as low as 1 

The inexpensive clear 

plastic dishes sold to put 

under potted plants will 

be ideal. The dish must

Newton (less than 2 lbs) 

Q Paper towels for cleaning the board between trials 

be a little smaller than the board.

Q Master 2.4c, Landslide Data Table 

Q Master 2.4d, Landslide Activity Sheet 

AGU / FEMA 92 S EISMIC S LEUTHS
Q Pencils or pens 

AGU / FEMA 93 S EISMIC S LEUTHS
Q Transparency made from Master 2.4e, Components of the Force of VOCABULARY 

Gravity 

Q Overhead projector 

Q Soil, gravel, or other materials for the extension (optional) 

Friction: mechanical 

resistance to the motion 

of objects or bodies that 

touch. 

Gravity: the force of attraction 

between any two objects with mass. 

Gravity is especially noticeable when 

an object of great mass, such as 

Earth, attracts an object of lesser 

mass. 

Landslide: an abrupt movement of 

soil and bedrock downhill in 

response to gravity. Landslides can 

be triggered by earthquakes or other 

natural causes. 

Loess: an unstratified, windblown 

mixture of clay, sand, and organic 

matter usually crumbly and buff or 

yellow-brown in color. 

Mass movement: the movement of 

surface material caused by gravity. 

Variable: in a scientific experiment, 

the one element that is altered to test 

the effect on the rest of the system. 

TEACHING CLUES AND CUES 

If you do not have 

enough scales you may 

do this section as a 

demonstration. You may 

also choose to simply describe the 

forces and use the factors in the data 

table below to describe how the 

measured weight of the material 

changes as the angle of the ramp 

changes. Whether you do the 

weighing or the students do, be sure 

to convert pounds into the metric unit 

Newtons (2.2 pounds = 9.8 

Newtons). 

PROCEDURE 

Teacher Preparation 

Assemble slides and/or photos. Assemble the other materials ahead of 

time and experiment with them to get a feeling for how various angles 

will affect their movement. Cover work surfaces with newspapers. 

A. Introduction 

Ask the students: Can an earthquake cause a landslide? Promote a 

discussion of their experiences and ideas. Show any images you have 

gathered of earthquake-related landslides, especially those that have 

affected your local environment. 

Explain to the students that not all landslides are earthquake related; 

many are caused by other natural factors. Landsliding, or mass movement, occurs when the forces that hold materials in place are exceeded 

by the force of gravity in the direction of motion. The forces that hold 

sand, soil, rocks, and buildings in place are related to the strength of the 

materials. The balance of these forces may be affected by the intensity 

of ground shaking during an earthquake. The steepness of the slope on 

which the materials rest determines how much the force of gravity acts 

in the direction of motion. 

B. Lesson Development 

1. Divide the class into cooperative groups of three or more students. 

Distribute one copy of Master 2.4c, Landslide Data Table, to each 

group. Ask one member from each group to collect a dish of sand and 

the other materials. 

2. Tell the students they will be conducting this investigation in a 

scientific manner. That is, they are to control the variables, manipulate 

only one, and measure or observe the response. When students have 

completed the experiment, it is very important that they use only their 

results to develop an explanation and that their explanation relates only 

to this particular model. Point out that the questions toward the end of 

the Landslide Activity Sheet relate to the scientific process they are 

employing. 

3. Instruct students to set up a ramp, as illustrated on Master 2.4c, and 

begin to explore the effect of the ramp’s angle on the weight the scale 

reads. Explain that the less weight the scale records, the greater the 

force of gravity parallel to the ramp and the weaker the force of friction 

that holds the material in place. Give these instructions: 

a. Place the scale at the bottom end of the ramp and place a dish of sand 

right side up on top of it. 

b. Raise one end of the ramp to the height corresponding to the first 

angle indicated on the Landslide Data Table. As you move from one 

angle to another, record the scale readings in the Landslide Data Table. 

AGU / FEMA 94 S EISMIC S LEUTHS
TEACHING CLUES AND CUES

If you made the arrows 

listed in the materials 

section, use them now to 

help students visualize 

these angles. Explain that the 

science of trigonometry deals with 

the mathematics of right triangles. 

Here you will simply measure and 

calculate the forces.

From 0-20 degrees not 

much will happen, but 

above 20 degrees, the 

students should begin to 

4. Stop the groups when they have completed the scale measurements 

and explain that the ramp breaks the force of gravity up into two 

components. Project the transparency of Master 2.4e, Components of 

the Force of Gravity, to illustrate. One of the components operates in a 

direction perpendicular to the ramp; that is the force they just 

measured. The other force operates along the ramp. That is the force 

of gravity, which will cause the landslide. These two components of 

gravity form two sides of a right triangle. Depending on the angle of 

the ramp, the force of friction may or may not cancel the force of 

gravity. 

5. To investigate the effect of slope on material with and without a 

simulated earthquake, ask the students to remove the scale. Show them 

how to place the dish of sand upside down at one end of the board 

without spilling the sand. First, place the board on top of the dish. 

Then, while holding the board down over the dish, carefully flip the 

board over. The dish should be upside down on the board with all the 

sand still in the dish. 

6. When all the groups have accomplished this, ask students to vary 

the angle of the ramp as they did before, this time by slowly raising 

the end of the board with the dish of sand. Instruct students to record 

the height at which the sand starts to slide, then lower the ramp by 

about 5 cm and tap on the ramp to simulate an earthquake. 

7. Give these instructions to test the effect of water on the sand: 

see some distinct motion. 

a. Again cover the dish with the board, flip the dish right side up, and 

add 225 ml of water to the sand. 

b. Flip the dish of wet sand back onto the ramp and repeat step 6 to see 

the effect each new angle of the ramp has on the wet sand. 

c. Continue to record your data and observations in the Landslide Data 

Table. Use the transparency of Master 2.4e, Components of the Force 

of Gravity, and Master 2.4d, Landslide Activity Sheet to answer the 

questions about force. 

C. Conclusion 

Allow time for students to respond to the last questions on the 

Landslide Activity Sheet, which ask them to develop an explanation 

for what they have observed. When they have finished, ask the groups 

to share their explanations, being certain to justify their explanations 

by citing their data. 

Ask the class if they think the work they have just done is similar to 

what scientists do. Ask them what the scientific community would do 

with a variety of explanations and varying data for the same 

procedure. Impress upon students that their investigation is one aspect 

of science and their reporting is another. Explain that it would take a 

great deal of time and many replications for any of their explanations 

to be accepted as a landslide theory. If they try the extension activities 

and want to carry their investigation of landslides still further, they 

will have to connect this model to real landslide data. 

AGU / FEMA 95 S EISMIC S LEUTHS
Finally, review and summarize the forces involved in landslides, 

referring to the illustrations on the handouts. Show the photos or slides 

again, and ask students to explain what they observe in terms of 

physical forces. 

ADAPTATIONS AND EXTENSIONS 

Invite students to test the effect of the material by repeating steps 6 

and 7 above with dishes of potting soil, gravel, and other materials. 

ACTIVITY THREE 

TSUNAMI: WAVES THAT PACK A WALLOP

VOCABULARY 

Amplitude: a measurement of the energy of a 

wave. Amplitude is the 

displacement of the 

RATIONALE 

Underwater earthquakes can cause very powerful seismic sea waves 

commonly called tsunami or (incorrectly) tidal waves. These waves 

can devastate a coastal community because of the tremendous amount 

of energy they carry. 

FOCUS QUESTIONS 

How do earthquakes cause seismic sea waves? 

What kinds of energy transfers are involved? 

What precautions can people take to limit tsunami damage? 

OBJECTIVES 

Students will: 

1. Prepare and present a class report that reflects their own research on 

seismic sea waves. 

2. Describe the characteristics of an average seismic sea wave in terms 

of speed, wavelength, and period, and predict its effects on a coastal 

community. 

3. Calculate the energy of the disturbance (sea floor motion) that 

causes an average seismic sea wave. 

MATERIALS 

Q Master 2.4f, Teacher Background Material 

Q Student copies of Master 2.4g, Tsunami Event Reports 

Q Student copies of Master 2.4h, Seismic Sea Waves Activity Sheet 

Q Transparency of Master 2.4i, Wave Characteristics and Energy 

Q Overhead projector 

Q Student copies of Master 2.4j, Seismic Sea Waves Energy Analysis 

medium from zero or the height of a 

wave crest or trough from a zero 

point. 

Period: the time between two 

successive wave crests. 

Run-up elevation or height: the 

highest attitude above the tide line, 

in meters, that the water reaches as 

it is forced up on land by a tsunami. 

Seismic sea wave: a tsunami 

generated by an undersea 

earthquake. 

Tsunami: a potential destructive 

ocean wave created by an 

earthquake or other large-scale 

disturbance of the ocean floor. This 

Japanese word has the some form in 

both the singular and the plural. 

Wave crest: the highest point a 

wave reaches. The lowest point is 

called its trough. 

Wave height: the vertical distance in 

meters from a wave’s crest to its 

trough. (This measurement will be 

twice the amplitude measured for the 

some wave.) 

Wavelength: the horizontal distance 

between two successive crests, 

often measured in meters.

Q Copies of Master 2.4k, Seismic Sea Waves Research and Report 

Form, one for every two students 

Q A large coil, telephone cord, or hose for demonstrating wave action 

Q Numerous student copies of Master 2.41, Grading Matrix 

AGU / FEMA 96 S EISMIC S LEUTHS
Q Poster board or chart paper, markers, and audiovisual equipment as 

available 

Q Video camera (optional) 

PROCEDURE 

Teacher Preparation 

Read the teacher background information on tsunami. Locate some 

before and after photos of tsunami, and either make transparencies or 

have them available to pass around the room. TEACHING CLUES & CUES 

Check your school and community libraries for the periodicals listed at 

the end of this lesson and in the Unit Resources. Also look for beginning 

oceanography textbooks and back issues of Scientific American. 

You may want to review 

scientific notation before 

handling the large 

numbers in this activity. 

A. Introduction 

If you have photos, share them with the class. Then pass out copies of 

Master 2.4g, Tsunami Event Reports. Have students take turn reading 

the accounts aloud. Ask students what they think causes tsunami. 

B. Lesson Development 

1. To provide the students with some common language, pass out 

Master 2.4h, the Seismic Sea Wave Activity Sheet, and help the class 

work through it. Project the upper half of Master 2.4i, Wave 

Characteristics and Energy. Ask students to tell you what belongs in 

each blank, and label the wave form accordingly. Point out that waves 

never stand still, so we have to be very clever to measure their 

characteristics. 

2. Pose this question: How can a fault movement of only one meter in 

the depths of the ocean cause a huge wave to strike land? Promote 

student discussion until someone mentions the energy involved. At 

that point, project the lower half of Master 2.4i, and show students 

how the uplift of one meter actually involves lifting a column of water 

the same size as the area of seafloor uplifted. 

3. Pass out copies of Master 2.4j, Seismic Sea Waves Energy 

Analysis. Work through the activity as a class or have students 

complete the worksheets in pairs, depending on their previous 

preparation. 

AGU / FEMA 97 S EISMIC S LEUTHS
TEACHING CLUES & CUES 

You may want to videotape the presentations 

by setting the camera up 

on a tripod very close to 

4. Challenge students to explain how a wave that is only one meter 

high in the ocean can grow so high as to overwhelm the land. Again 

direct their attention to the lower half of 2.4i, and point out the energy 

involved. (As the wave nears shore, in shallow water, the energy is 

forced upward, or refracted. See Master 2.4f for more detail.) 

5. Invite students to do some research on actual tsunami drawn from 

the table of Notable Tsunami (below) or from other sources. Hand out 

one Seismic Sea Waves Research and Report Form (Master 2.4k) to 

every two students, explaining that each team is to research a specific 

topic and report what they learn to the class. Two students will report 

on tsunami warning systems; the others will report on a particular 

tsunami drawn from the list below. Set a due date and establish how 

you are going to evaluate the report. If you will use the matrix 

provided, explain it now. 

the presenters. If you film your first 

class, you can use the footage to 

show other classes what you are 

looking for. 

Notable Tsunami by Place Reported 

November 1, 1755 Lisbon, Portugal 

April 2, 1868 Hilo, Hawaii 

June 15, 1896 Sanriku, Japan 

August 13, 1868 Arica, Peru 

August 27, 1883 Java, eruption of Krakatau 

(also spelled Krakatoa) 

March 2, 1933 Sanriku, Japan 

April 1, 1946 Hilo, Hawaii 

March 9, 1957 Hilo, Hawaii 

May 23, 1960 Southern California 

March 28, 1964 Crescent City, California 

November 29, 1975 Hilo, Hawaii 

May 26, 1983 Minehama, Honshu, Japan 

July 12, 1993 Aonae, Japan 

6. Invite discussion of preventive measures that can be taken to 

minimize seismic sea wave damage. As students progress in their 

research, they may be able to suggest guidelines. The presentations on 

early warning systems will address this topic directly. 

7. When the due date for presentations is near, review how you will 

evaluate the presentations and specify the time limit for each. Provide 

poster board or chart paper and markers, overhead transparencies and 

pens, and slide or video apparatus if available. 

C. Conclusion 

Have the students present their reports. Before each presentation, 

distribute copies of the grading matrix. Ask students to use one matrix 

sheet for each presentation, taking notes in the space allotted and 

evaluating their peers’ presentations on the same criteria by which 

theirs will be graded. A respectful classroom atmosphere will ensure 

the success of these presentations. 

AGU / FEMA 98 S EISMIC S LEUTHS
ADAPTATIONS AND EXTENSIONS 

Challenge one pair of students to research and describe the compressional waves that have been associated with underwater earthquakes in 

terms of the wave’s characteristics and its effect on ships. V

AGU / FEMA 99 S EISMIC S LEUTHS
MASTER PAGE Teacher Background Reading 

Liquefaction 

2.4a 

How Liquefaction Occurs during Quakes 

Liquefaction happens during an earthquake when vibrations cause the pressures to build up in the ground water 

that occupies the pore spaces between the grains of sand, silt, or loess. The longer the duration of the earthquake, 

the more likely that liquefaction will be induced. The only solid strength of such a deposit is provided by the 

friction between grains touching each other. When the pressure in the water that fills the pore space between the 

grains is sufficient to spread them apart, the solid nature of the sand, silt, or loess deposit is changed into that of a 

viscous liquid: “quicksand” or “quickclay.” 

Because it takes time for the pressures that produce liquefaction to build up underground, and because quicksand 

is a heavy, thick fluid that moves slowly, conditions of liquefaction, sand boiling, and associated phenomena may 

not he apparent during the shaking. In fact, they often do not manifest until after the shaking has already passed, 

sometimes not until 10-20 minutes later. The quick conditions or boiling of the sand can persist for hours or even 

days after the quake, sometimes as much as a week. 

How Big Does It Take & How Near to the Quake? 

A natural question regarding seismically induced liquefaction is how big an earthquake is required to induce 

quick conditions and how close it has to be for such effects to be possible. With regard to size, several technical 

publications suggest that liquefaction does not occur for earthquakes less than Richter magnitudes of 5.2. 

However, minor liquefaction effects in areas underlaid by particularly ideal predisposing conditions (loose sand 

deposits saturated with a near-surface water table) have been observed for earthquakes as small as 4.7 on the 

Richter scale in the New Madrid Seismic Zone. Minor damage to vulnerable structures has occurred in such areas. 

With regard to distance, an earthquake in June of 1987 of magnitude 5.2 in southeastern Illinois caused 

liquefaction phenomena near Bell City, Missouri, 150 miles (240 km) from the epicenter. A swimming pool, two 

large grain bins, a carport, and three houses were damaged (one severely). There was also fissuring and lateral 

spreading. At the same time, points nearer the epicenter of that quake did not experience such ground failures. 

Three years later in 1990 this same area experienced no liquefaction phenomena when a 4.7 earthquake struck 

only 20 miles (32 km) away. 

Nearness to the epicenter implies greater amplitudes of ground motion, but distance implies a longer duration of 

shaking, since the wave train consists of many waves traveling at a variety of speeds. The epicenter of the 

magnitude 8.1 earthquake that struck Mexico City in 1985 was 240 miles (384 km) away and induced 

liquefaction that severely damaged some buildings. Although lasting less than a minute at its distant source, that 

quake lasted several minutes in Mexico City. Ground shaking amplitudes within the city, were never large, yet 

400 buildings collapsed, resonating with the long-lasting wave train (or sequence of waves) amplified by 

underlying clays. 

The New Madrid earthquakes of 1811-12 induced extreme examples of liquefaction, manifesting as sand boils 

and explosion cratering in the area of St. Louis, Missouri, and across the river in the flood plain of Illinois. 

Liquefaction also occurred from those quakes as far as Cincinnati, Ohio, more than 300 miles (480 km) away. 

Three Ways to Induce Liquefaction 

Liquefaction in soils can be stimulated three ways: seismically, mechanically, and hydrologically. Seismicallyinduced liquefaction is caused by seismic waves. Mechanically-induced liquefaction is caused by vibrations that 

come from railroad trains, motor vehicles, tractors, and other mechanical sources of vibratory ground motion. 

Hydrologically-induced liquefaction occurs when ground-water pressures increase due to rising stream levels 

AGU / FEMA 100 S EISMIC S LEUTHS
MASTER PAGE 

during flooding conditions. This type of liquefaction most commonly occurs on properties protected by levees, 

where rivers can rise to levels above the land surface without actually flooding the land. Most of the New Madrid 

Seismic Zone falls into this category, being surrounded by levees that flank the rivers and drainage ditches 

throughout the area. Because of this, seismically-induced sand boils became hydrologically active during river 

flood stages, and can turn into quicksand and boil again, just as they did during the earthquakes that formed them. 

Similarly, tractors, trains, and trucks crossing over sand fissures during times of high water table can 

mechanically induce liquefaction, causing highways to sag, railroad tracks to get out of parallel, and farm 

equipment to sink into the ground. 

Note: Adapted from Stewart, David, and Knox, Ray, The Earthquake That Never Went Away: The Shaking Stopped in 1812, 

but the Impact Goes On, Marble Hill, MO: Gatlinburg-Richter Publications, 1993. 

AGU / FEMA 101 S EISMIC S LEUTHS
MASTER PAGE New Madrid Narrative

(A 1912 Account of the 1811-1812 Earthquakes)

2.4b 

The First Day 

At 2:30 on the morning of December 16, 1811, a tremendous earthquake occurred whose epicentral region is thought to have 

been just west of the location of present day Blytheville, Arkansas, a city that did not exist at the time. Had it been there, it 

would have been devastated totally, as evidenced by the numerous earthquake boils and fissures that visibly surround the 

city today. The Richter surface wave magnitude is thought to have been 8.6. President James Madison, 800 miles (1280 km) 

away in the White House in Washington, DC, was shaken out of bed by the quake. 

Many aftershocks immediately followed, some probably magnitude 6.0 or greater. At least two more of the December 16 

shocks are thought to have equaled 8.0 on the Richter scale. 

Then, some time around 11:00 a.m., another great shock occurred in the vicinity of present-day Caruthersville, which to the 

residents there at the time seemed worse than the first. This one is thought to have been another magnitude 8.0. However, 

present-day Caruthersville wasn’t there at the time. It was not founded until 1857. In 1811 another village occupied that site.

It was called Little Prairie, Missouri. 

The River Rampages, and Towns Disappear 

The Mississippi River was churned into a virtual maelstrom, with miles of banks caving in, boats being swamped and sunk, 

and even entire islands disappearing along with their human occupants. 

Two towns disappeared at this time. One settlement to disappear on December 16, 1811, was Big Prairie, Arkansas. At the 

confluence of the Mississippi and St. Francis Rivers, the town site liquefied and sank, but slowly enough for all residents to 

safely escape. There were about 100 people there at the time. The Mississippi River now occupies that site. 

Another community destroyed that day was Little Prairie, Missouri, near present-day Caruthersville. Eyewitness accounts of 

the horror tell us of people being violently thrown from their beds in the middle of the night. It had been a bright full moon,

but shortly after the shock everything became pitch black because of the dust. People were injured and bleeding, and some 

were even knocked temporarily unconscious. 

The earth continued to jerk and rumble through the darkness until daylight, when, around 8:00 a.m. the second hard shock 

hit the area. Throughout the morning more shocks continued, with the ground heaving and cracking, sometimes opening and 

then suddenly slamming shut, spewing ground water over the tops of tall trees. In some places the ground literally exploded, 

blasting debris high into the air, raining sand and carbonized wood particles down upon the heads of those nearby, while 

leaving a deep crater in the ground where smooth land had been before. Sometimes the earth formed spreading crevasses 

beneath the bases of large trees, splitting their trunks from their roots upwards beyond the levels of their limbs. At one point 

during the morning a great fissure began to form within the town. The townspeople stood around that pit and watched, 

horrified, as dark, viscous fluids gurgled from beneath the earth while gaseous fumes and the smell of sulfur and brimstone 

filled the air. 

Many were thinking that the end of the world was at hand and that the very gates of hell itself were opening up to take their 

village. Amidst the terror, after the third great shock around 11:00 a.m., the soils of their settlement began to turn into 

quicksand, with dark waters oozing from the pores of the earth. As their whole town began to sink their streets and cabins 

were flooded, not from the river, but from the ground itself. 

Escape from Little Prairie 

Hastily, the residents of Little Prairie gathered what meager possessions they could hold, lifted small children to their 

shoulders, and waded westward. Looking ahead of themselves, they could see the rising waters far off on the horizon. For 

eight miles (12.8 km) they waded through waist-deep waters, never knowing from one step to the next if they were going to 

plunge headlong into an unseen crevasse or trip over a buried stump, all the while surrounded by snakes, coyotes, and other 

wild creatures swimming for their lives in that turgid flood. During their escape, they did not know if they would live 

through the day or not, but all did survive. 

The First Day Was Over, but the Worst Was Yet to Come 

What has been described, thus far, was only the first day of the Great New Madrid Earthquake series. More and bigger 

tremors were yet to come. At about 9:00 a.m. on January 23, 1812, another of the really big ones hit. This was probably 

centered north of Little Prairie and south of Point Pleasant, a small settlement there at the time. It is thought to have been an 

8.4 magnitude earthquake.

AGU / FEMA 102 S EISMIC S LEUTHS
MASTER PAGE 

The Mississippi River bank, on which the village of Point Pleasant was situated, collapsed during the January 23 event. 

Fortunately, the residents had all evacuated the site prior to that catastrophe so that none were injured. The town, however, 

was lost forever. 

The January 23 event also caused several huge sand boils in Tennessee that created a dam across Reelfoot Creek. This 

created “Reelfoot Lake.” 

On February 7, 1812, came the largest quake of all. At about 3:15 in the morning the region was rocked by an 8.8 magnitude 

shock. Outside of Alaska, that is the largest earthquake in American history and one of the largest in the world. 

This is the quake that caused the Mississippi River to run backwards. It caused such towering waves of water to be thrown 

over the banks that thousands of acres of trees were shattered into splinters and stumps. It threw boats up on dry land along 

St. John’s Bayou at New Madrid. And it created two temporary waterfalls. These falls had a vertical drop of about six feet 

(2 m) followed by a mile (2 km) or so of shallow rapids. 

During the largest of the New Madrid earthquakes, the river is said to have boiled, whirled, and heaved with massive waves 

bashing from one bank to the other, sweeping boats and debris into oblivion. Some eyewitnesses from the banks said they 

actually saw the river open up in yawning chasms, into which the swirling waters disappeared, drawing hapless flat boats 

and their passengers into the maelstrom, never to be seen again. Others said water spouts would shoot upwards from the 

waters surface, like tall fountains. 

The earthquakes had literally destroyed the landscape with sand deposits, crevasses, and permanent flooding. Most residents 

of the region abandoned their properties and moved away. The boot-heel portion of Missouri was nicknamed “Swampeast 

Missouri” sometime after the quakes. 

Two More Towns Gone Forever 

The February 7 quake destroyed two other towns, wiping them forever from the face of the earth. One was Fort Jefferson, 

Kentucky, swept away by landslides. These slumps are still visible today along Highway 51 leading into Wickliffe. The 

other lost town was New Madrid itself. What was left of the settlement slumped downward 15-20 feet (5-10 m) into the 

water’s edge and was washed away by the spring floods of 1812. 

The throbs and throes of terra firma wrought by the Great New Madrid Earthquakes of 1811-12 trouble us no more. Though 

the motions of these gargantuan ground vibrations ceased in 1812, their impact goes on. Permanent traces of their violence 

lie scattered over a 5,000 square mile (12,000 sq km) area spanning five states. 

Note: This account was adapted with only minor changes from Fuller, Myron L., The New Madrid Earthquakes of 1811-

1812, A Scientific Factual Field Account, USGS Bulletin 494, Washington, DC: Government Printing Office, 1912; 

reprinted by Southwestern Missouri University Center for Earthquake Studies, 1990. Please keep in mind that the numerical 

Richter magnitudes quoted in this book were not determined by instrumental measurements as they are today, because these 

events predated the invention of reliable seismographs.

AGU / FEMA 103 S EISMIC S LEUTHS
2.4c MASTER PAGE Landslide Data Table

Name _________________________________________________________________ Date _____________________ 

Ramp and Force Measurements 

Angle Height Force 

10°

20°

30°

40°

50°

60°

Effect of Height on Materials 

Material Angle Height Effect of simulated earthquake (1 tap) 

Dry 

Sand 

Wet 

Sand 

Dry 

Soil 

Wet 

Soil 

Other 

Other 

AGU / FEMA 104 S EISMIC S LEUTHS
2.4c MASTER PAGE Landslide Data Table (key)

Ramp and Force Measurements 

(Note: answers will vary) 

Angle Height Force 

10° 17 cm 

20° 34 cm 

30° 50 cm 

40° 64 cm 

50° 77 cm 

60° 87 cm 

Effect of Height on Materials 

(Note: answers will vary) 

Material Angle Height Effect of simulated earthquake (1 tap) 

Dry 

Sand 

30° 40-50 cm Sand moved about 1 cm per knock 

Wet 

Sand 

30°-40° 55-65 cm Sand moved about 2 cm per knock 

Dry 

Soil 

30°-40° 50-60 cm Sand moved about 1 cm per knock 

Wet 

Soil 

30°-40° 50-60 cm Sand moved about 2 cm per knock 

Other 

Other 

AGU / FEMA 105 S EISMIC S LEUTHS
2.4d MASTER PAGE Landslide Activity Sheet

Name ___________________________________________________________ Date _____________________ 

Group Names/Roles 

_____________________________ _____________________________ 

_____________________________ _____________________________ 

1. Why do you think the scales measure less weight as one end of the ramp is raised? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

2. At what height or what angle does the dry sand slide? 

___________________________________________________________________________________________ 

Why do you think it slides then, in terms of forces? 

___________________________________________________________________________________________

___________________________________________________________________________________________ 

3. What effect does the simulated earthquake (knocking on the ramp) have on the dry sand? 

___________________________________________________________________________________________ 

Why do you think the simulated earthquake has that effect? 

___________________________________________________________________________________________

___________________________________________________________________________________________ 

4. Before testing wet sand, what effect do you think wetting the sand will have on the slide angle? Why? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

5. What effect did wetting the sand have on its slide angle? Why? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

AGU / FEMA 106 S EISMIC S LEUTHS
2.4d MASTER PAGE Landslide Activity Sheet

6. What effect does the simulated earthquake (knocking on the ramp) have on the wet sand? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

AGU / FEMA 107 S EISMIC S LEUTHS
MASTER PAGE 

7. How did you control the following variables? 

a. height or angle 

___________________________________________________________________________________________ 

b. quantity of material 

___________________________________________________________________________________________ 

c. amount of moisture 

___________________________________________________________________________________________ 

d. surface condition 

___________________________________________________________________________________________ 

e. other 

___________________________________________________________________________________________ 

8. How did you insure that only one variable was changed at a time? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

9. From your data, try to explain how earthquakes affect landslides in as much detail as possible. 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

10. How could you test your explanation? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

11. What was interesting or unexpected in the investigation? Why? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

AGU / FEMA 108 S EISMIC S LEUTHS
2.4d MASTER PAGE Landslide Activity Sheet (key)

Date: 

1. Why do you think the scales measure less weight as one end of the ramp is raised? 

Some of the weight is acting along the ramp. The scale doesn’t record that weight. 

2. At what height or what angle does the dry sand slide? 

40-50 cm, or about 30 degrees. 

 Why do you think it slides then, in terms of forces? 

The force of gravity along the ramp is greater than the frictional forces. 

3. What effect does the simulated earthquake (knocking on the ramp) have on the dry sand? 

The sand slides a bit with each knock. 

 Why do you think the simulated earthquake has that effect? 

It must reduce the frictional forces because gravity remains constant. 

4. Before testing wet sand, what effect do you think wetting the sand will have on the slide angle? Why? 

It will probably slide more easily because the water reduces the friction. 

5. What effect did wetting the sand have on its slide angle? Why? 

The sand seemed to stick to the ramp, so it required a sharper angle to make it slide. 

Surface tension causes the sand to adhere to the ramp. 

6. What effect does the simulated earthquake (knocking on the ramp) have on the wet sand? 

It slid further with each knock. 

AGU / FEMA 109 S EISMIC S LEUTHS
MASTER PAGE 

7. How did you control the following variables? 

 a. height or angle 

Used a meter stick according to the table. 

 b. quantity of material 

Filled the dish full each time. 

 c. amount of moisture 

Measured 225 ml. 

 d. surface condition 

Used only one type of sand. 

 e. other 

 

8. How did you insure that only one variable was changed at a time? 

We carefully observed and recorded after each change. 

9. From your data, try to explain how earthquakes affect landslides in as much detail as possible. 

An earthquake will cause a “slidable” piece of material to move a certain amount for each jolt. 

10. How could you test your explanation? 

Repeat the investigation. Compare our explanation to others. Look into real landslide data. 

11. What was interesting or unexpected in the investigation? Why? 

The addition of water did not lower the angle required for the sand to slide. 

AGU / FEMA 110 S EISMIC S LEUTHS
MASTER PAGE Components of the 

Force of Gravity

2.4e 

AGU / FEMA 111 S EISMIC S LEUTHS
 

AGU / FEMA 112 S EISMIC S LEUTHS
MASTER PAGE Teacher Background Reading 

Seismic Sea Wave 2.4f 

A seismic sea wave is created when a fault in the ocean floor moves vertically. The energy of the lifted or lowered 

water radiates outward as very long shallow water waves commonly (and erroneously) called “tidal waves.” 

Because these waves have nothing to do with the attraction of the Moon or the Sun, scientists prefer the Japanese 

word tsunami, which means “wave in the harbor,” or the English term seismic sea wave. 

Most seismic sea waves, like most earthquakes, occur around the Pacific Ocean, but there have been great seismic 

sea waves in most regions of the Earth. 

The great destructive power of these waves comes from the huge energy imparted to the water by fault 

movement. To equate this energy to mechanical work, we can imagine the work needed to lift an average volume 

of ocean water a distance (d) of 1 meter. The average depth of the ocean (h) is 3.8 km. The average surface area 

(A) of the ocean floor moved up or down by such an event, according to seismic sea wave research, is 20,000 

square kilometers—a 200 km x 100 km piece of seafloor about the size of New Jersey. The volume (V) of 

seawater lifted would then be 76,000 cubic kilometers. If we take 1.03 kg/m3

 as the density (D) of seawater, the 

mass (m) of that seawater would be about 78 billion metric tons. To lift this much water by 1 m would take 7.6 x 

1014 Joules, the energy of 183 kilotons of TNT. See Master 2.4j for a complete quantitative analysis. 

This energy radiates outward from the epicenter as a wave train of low waves, not as a single large wave. Each of 

these seismic sea waves has an average amplitude of 1 meter, wavelengths over 100 km, and periods of 7-15 

minutes (for short-period tsunami) or over 40 minutes (for long-period tsunami). These waves travel at speeds 

between 550 and 800 kilometers per hour before encountering land. 

Speed=550 to 800 km per hour 

Period=7-15 min or > 40 min 

Seismic Sea Wave Characteristics 

Seismic sea waves are very different from wind-generated sea waves. Normal wind waves rarely have 

wavelengths over 300 meters, and generally travel under 100 km/hr. A medium-sized tsunami can have 

wavelengths of 150 km and travel at 550–800 km an hour. Tsunami are like tides in that a low tide is followed by 

a high tide, but in the case of a tsunami dramatic high and low tides can be only tens of minutes apart. This may 

be the origin of the expression tidal wave. 

As seismic sea waves encounter land, they cause rapid tide-like motion. The trough of the waves causes very low 

tides, while the wave crests may cause a run as high as 32 meters. Sometimes seismic sea waves can cause 

enormous breaking waves. The mechanism for these waves is very similar to that of wind waves; the friction of 

the ocean bottom slows the troughs and the crests move over them and break. Thus the characteristics of seismic 

sea waves when they hit land, like those of wind waves, are very much related to the characteristics of the nearshore ocean bottom and the shoreline. 

AGU / FEMA 113 S EISMIC S LEUTHS
MASTER PAGE 

The depth of the ocean water also controls the speed of seismic sea waves. As the depth changes, the wave’s 

speed and direction change, resulting in the phenomenon we call refraction—the change in direction of a wave as 

it moves from one medium to another. 

Extensive international cooperation has developed a tsunami early warning system for the Pacific Islands. A 

system for the U.S. Pacific Coast is being developed. The older system is centered at the Pacific Tsunami 

Warning Center in Honolulu, where data are collected from seismic observatories across the globe. The Center 

evaluates the potential of a tsunami and institutes special observations at various tsunami watch stations. All these 

data are verified and emergency preparation procedures are put into effect when necessary. 

Causes Other Than Earthquakes 

Not all destructive sea waves are caused by earthquakes. Some are caused by landslides and volcanic eruptions 

and some are artificially created by events like underwater nuclear explosions. In 1883, the Krakatoa Island 

volcano erupted, blowing the island away down to a depth of about 43 m below sea level. This event caused giant 

waves that killed some 36,000 people in Java and Sumatra. 

AGU / FEMA 114 S EISMIC S LEUTHS
2.4g MASTER PAGE Tsunami Event Reports

1. On July 12, 1993, the Hokkaido-Nansei-Oki earthquake of magnitude 7.8 produced one of the largest seismic 

sea waves in Japan’s history. The tsunami hit the Okushiri coast within five minutes after the main shock, causing 

waves at the shoreline between 15 and 30 m high. The town of Aonae on the island of Okushiri suffered extensive 

damage. At least 185 people were killed, with property damage estimated at $600 million. 

2. The Prince William Sound, or Anchorage, Alaska, earthquake of March 27, 1964, caused seismic sea waves 

generated by an underwater landslide. At Valdez, the earthquake triggered a landslide that deepened the harbor by 

as much as 100 m in one place and caused a tremendous tsunami. In addition, the earthquake uplifted the sea floor 

by as much as 4 meters. The tsunami killed 119 people in Alaska, Hawaii, and California and caused over $282 

million in damage. 

3. On April 1, 1946, at 53.5o north and 163o west, 130 km southeast of Unimak Island, Alaska, a large earthquake 

occurred 4,000 m below the ocean surface in the Aleutian Trench, causing an undersea landslide. Four and one 

half hours later, a tsunami reached Oahu, Hawaii, after traveling 3,600 km at 800 km/hr. Water rose 12 m above 

the high tide line on Oahu and 18 m on Hawaii (the “Big Island”). This seismic sea wave demolished 488 homes 

and damaged 936 others, with property loss estimated at $25 million and 173 people killed. 

4. An earthquake on the ocean floor may also cause a compressional wave that can severely damage ships close to 

the epicenter of the event. Even though we consider fluids as non-compressional in systems like automobile 

brakes, compressional waves can travel in seawater under the tremendous pressures and accelerations of the water 

in underwater seismic events. Ships struck by these waves report an experience similar to running aground or 

striking another vessel. 

In 1969, a magnitude 8.0 earthquake west of Gibraltar caused compressional waves that struck the 32,500-ton 

tanker Ida Knudsen, sailing in 4,900 m of water. The tanker was 35 km from the epicenter of the seaquake and 

suffered so much damage that at first it was declared a total loss. The ship was later extensively rebuilt. 

AGU / FEMA 115 S EISMIC S LEUTHS
AGU / FEMA 116 S EISMIC S LEUTHS
MASTER PAGE 

Seismic Sea Waves 

Activity Sheet

2.4h 

Name _________________________________________________________________ Date _____________________ 

Characteristics of a Seismic Sea Wave 

Label the following characteristics and state the average values. 

A Possible Tsunami Scenario 

Imagine that a magnitude 6.8 earthquake occurs 1,625 km from a coastal town on a strike-slip fault in the ocean 

floor, where the water is 3.8 km deep. A wave train is generated with a speed of 650 km/hr and wavelengths of 

150 km. The National Tsunami Warning Center alerts the townspeople. 

1. How long will it take the tsunami to hit the coastal town? 

___________________________________________________________________________________________ 

2. The first wave hits at 2:00 p.m. Does Jen have time to rescue the boom box left on the beach before the next 

wave hits? Calculate the period of the waves. (Period is wavelength divided by speed.) 

___________________________________________________________________________________________

___________________________________________________________________________________________ 

3. Describe what might happen when this seismic wave encounters the coastal town. 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

4. What could be done to prepare for this tsunami? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

AGU / FEMA 117 S EISMIC S LEUTHS
MASTER PAGE 

Seismic Sea Waves 

Activity Sheet (key)

2.4h 

Characteristics of a Seismic Sea Wave 

Label the following characteristics and state the average values. 

A Possible Tsunami Scenario 

Imagine that a magnitude 6.8 earthquake occurs 1,625 km from a coastal town on a strike-slip fault in the ocean 

floor, where the water is 3.8 km deep. A wave train is generated with a speed of 650 km/hr and wavelengths of 

150 km. The National Tsunami Warning Center alerts the townspeople. 

1. How long will it take the tsunami to hit the coastal town? 

Time = Distance / Speed = 1,625 km = 2.5 hours 

650 km / hr 

2. The first wave hits at 2:00 p.m. Does Jen have time to rescue the boom box left on the beach before the next 

wave hits? Calculate the period of the waves. (Period is wavelength divided by speed.) 

Period = Wavelength / Speed = 150 km = .23 x 60 = 13.8 min 

650 km / hr 

3. Describe what might happen when this seismic wave encounters the coastal town. 

There would be very high and very low water with only minutes in between. 

4. What could be done to prepare for this tsunami? 

People could be warned to move to high ground. 

AGU / FEMA 118 S EISMIC S LEUTHS
2.4i MASTER PAGE Wave Characteristics and Energy

AGU / FEMA 119 S EISMIC S LEUTHS
AGU / FEMA 120 S EISMIC S LEUTHS
MASTER PAGE 

Seismic Sea Waves 

Energy Analysis 2.4j 

Name _________________________________________________________________ Date _____________________ 

To calculate the minimum energy needed to cause an average seismic sea wave, we can calculate the work 

needed to give a particular volume of ocean water some gravitational potential energy. In essence, this means 

calculating the product of the force needed to lift a particular volume of water and the height to which it is lifted. 

Using the average values from tsunami research to carry out the following steps, calculate the energy released by 

an earthquake on the sea floor that starts a seismic sea wave. 

1. What is the average sea floor area that moves in an earthquake that results in a seismic sea wave? 

2. Knowing that the average ocean depth (h) is 3.8 km, what volume (V) of water is moved in the disturbance that 

causes a seismic sea wave? (Use the formula V = Ah.) 

3. This volume of ocean water has a certain mass. Knowing the density (D) of ocean water to be 1.03 kg/m3

, 

calculate the mass (m) of the water moved by the quake. (Use the formula m = DV.) 

(note: 1 km3

 = 1 x 109 m

3

) 

4. To lift that mass of ocean water requires a force that is at least equal to water’s weight. Using 9.8 m/s2

 as the 

acceleration due to gravity (g), calculate the force (F) needed to lift that much ocean water. 

AGU / FEMA 121 S EISMIC S LEUTHS
MASTER PAGE 

5. Supposing that volume of ocean water is lifted an average height (d) of one meter, how much work (W) is 

done? This value represents the energy imparted to the seismic sea wave by the earthquake. 

6. How much energy is this in equivalent tons of TNT? 1 Ton TNT = 4.18 x 109

 Joules 

7. Imagine this much energy spreading over a great area, but then being applied to say only 3.8 meters of water 

instead of 3.8 kilometers. How high might the 3.8 meters of water be lifted? 

AGU / FEMA 122 S EISMIC S LEUTHS
MASTER PAGE 

Seismic Sea Waves 

Energy Analysis (key)

2.4j 

1. What is the average sea floor area that moves in an earthquake that results in a seismic sea wave? 

A = 20,000 km2

2. Knowing that the average ocean depth (h) is 3.8 km, what volume (V) of water is moved in the disturbance that 

causes a seismic sea wave? 

Volume of seawater: V = Ah = (20,000 km2

)(3.8 km) = 7.6 x 104 km3

= 76,000 km

3. This volume of ocean water has a certain mass. Knowing the density (D) of ocean water to be 1.03 kg/m3

, 

calculate the mass (m) of the water moved by the quake. To convert km3

 to m3, multiply by 10 m3/km3. 

Density of seawater: D = 1.03 x 103

 kg/m3

Mass of seawater lifted: 

m = DV = (1.03 x 103

 kg/m3)(7.6 x 104 km3) = (1.03 x 103 kg/m3) (7.6 x 104 km3) (109 m

3

/km3) 

7.8 x 1016 kg or 78 trillion metric tons 

(note: 1 km3

 = 1 x 109m

3

)

4. To lift that mass of ocean water requires a force that is at least equal to water’s weight. Using 9.8 ms2

 as the 

acceleration due to gravity (g), calculate the force (F) needed to lift that much ocean water. 

Acceleration due to gravity: g = 9.8 m/s2

Force due to gravity or weight of seawater: 

F = mg = (7.8 x 1016 kg)(9.8 m/s2

) = 7.6 x 1017 Newtons

AGU / FEMA 123 S EISMIC S LEUTHS
MASTER PAGE 

5. Supposing that volume of ocean water is lifted an average height (d) of one meter, how much work (W) is 

done? This value represents the energy imparted to the seismic sea wave by the earthquake. 

Distance lifted: d = 1 m 

Work done against gravity: 

W = Fd = (7.6 x 1017N)(1 m) = 7.6 x 1017 Joules.

6. How much energy is this in equivalent tons of TNT? 

Conversion factor: 4.18 x 109

 Joules = 1 Ton TNT 

W = Energy = (7.6 x 1017 Joules) (1 Ton TNT/4.18 x 109

 Joules)

Energy = 1.8 x 108

 Tons TNT or 180 Megatons TNT 

7. Imagine this much energy spreading over a great area, but then being applied to say only 3.8 meters of water 

instead of 3.8 kilometers. How high might the 3.8 meters of water be lifted? 

If all the energy were applied to only 3.8 meters of water (1/1,000th), then the water would rise 1,000 meters 

instead of only one meter. The energy spreads out very rapidly, so maybe only 1/100th of the energy reaches the 

3.8 meters of water. In this case the water would rise 30 meters—quite a sizeable wave.

AGU / FEMA 124 S EISMIC S LEUTHS
MASTER PAGE 

Seismic Sea Wave Research 

and Report Form

2.4k 

Name _________________________________________________________________ Date _____________________ 

Event 

___________________________________________________________________________________________________ 

___________________________________________________________________________________________________ 

___________________________________________________________________________________________________ 

___________________________________________________________________________________________________ 

Cause 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

Characteristics of the tsunami 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

Damage 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

What could have been done to prevent the damage?

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

Information Source

Title: _________________________________________________________ 

Author: _______________________________________________________ 

Publisher and place of publication: _________________________________ 

Date: ____________________________ 

AGU / FEMA 125 S EISMIC S LEUTHS
AGU / FEMA 126 S EISMIC S LEUTHS
2.4l MASTER PAGE Grading Matrix

Score 4 points

Students clearly communicate all the facts about their event, covering each of the categories on the Seismic Sea 

Wave Research and Report Form. While reporting the wave’s characteristics and energy, students connect the 

Wave Characteristics and Effects activity sheet and the Energy Analysis activity to their event. The students 

employ logical thought processes and a knowledge of today’s safety practices in their discussion of damage 

prevention. They use some visual method of communicating their ideas, such as the board, an overhead, a video, a 

poster, or a demonstration. 

Score 3 points 

Students clearly communicate all the facts about their event, covering each of the categories on the Seismic Sea 

Wave Research and Report Form. They do not effectively connect the Wave Characteristics and Effects activity 

sheet and the Energy Analysis activity to their event. The students’ discussion of preventive measures is good. 

They use the board, an overhead, a video, a poster, or a demonstration in their report. 

Score 2 points

Students clearly communicate all the facts about their event, covering each of the categories on the Seismic Sea 

Wave Research and Report Form. They superficially mention wave characteristics, wave energy, and preventive 

measures, or they cover one of these three, but not the others. They rely mainly on the spoken word to 

communicate their information and ideas. 

Score 1 point 

Students report the facts of their event by reading directly from the Seismic Sea Wave Research and Report Form. 

They hardly mention wave characteristics and energy. The discussion of preventive measures, if any, is 

incomplete. They do not use any visual communication aides. 

Score 0 points

Students report incorrect information. The Seismic Sea Wave Research and Report Form was poorly completed 

and the presentation to the class is poor. Statements about the wave’s characteristics, its energy, and damage 

prevention are missing or inaccurate. 

AGU / FEMA 127 S EISMIC S LEUTHS
AGU / FEMA 128 S EISMIC S LEUTHS
2.5 

RATIONALE 

City planners, developers, builders, and buyers need information about 

soil and subsoil geology in order to choose sites and design structures 

that will best withstand ground shaking and other earthquake hazards. 

FOCUS QUESTIONS 

What are the important geologic considerations when choosing a 

building site and designing or reinforcing a building for earthquake 

survivability? 

Have these considerations been taken into account in the planning of 

towns and cities? 

OBJECTIVES 

Students will: 

1. Interpret soil- and earthquake-related geologic maps. 

2. Apply these interpretations in choosing a building site and an 

earthquake-resistant building design. 

3. Locate information about the soils and geology of their local TEACHING CLUES AND CUES

community and apply the same process to interpret it. 

MATERIALS 

Sample maps are provided so students can do 

this activity without any 

special preparation. 

Q Student copies of Master 2.5a, Background Reading: Site 

Characteristics 

Q Unit 1 Resource List 

Q Master 2.5b, Soil and Geologic Maps and Map Sources 

Q Student copies of Master 2.5c, Surface Map, Soil Map, Geologic 

Map, and Hazard Map (4 pages) 

Q Transparencies made from Master 2.5c, Surface Map, Soil Map, 

Geologic Map, and Hazard Map (4 pages) 

Q Overhead projector 

Q Local map prepared in Unit 1 

However, the activity will be most 

meaningful to students if they can 

relate it to their own area. Master 

2.5b, Soil and Geologic Maps and 

Map Sources, suggests types of 

maps that would be appropriate and 

where to get them. The Unit 1 

resource list suggests many other. 

sources. if you have trouble locating 

maps, call your county or state 

geology office or the USDA Soil 

Service and ask for help. 

AGU / FEMA 129 S EISMIC S LEUTHS
VOCABULARY 

Fault: a break or 

fracture in Earth’s crust 

along which movement 

has taken place. 

Landfill: a site where soil has been 

deposited by artificial means—often, 

where garbage or rubbish has been 

disposed of, then covered with dirt 

and compacted. 

Landslide: an abrupt movement of 

soil and bedrock downhill in 

response to gravity. Landslides can 

be triggered by an earthquake or 

other natural causes. 

Liquefaction: the process in which 

a solid (soil) takes on the 

characteristics of a liquid as a result 

of an increase in pore pressure and 

a reduction in stress. 

Sedimentary deposits: accumulation of solid particles that originated 

from the weathering of rocks and 

that have been transported or 

deposited by wind, water, and ice. 

Seismic: of or having to do with 

earthquakes. 

Slump: a type of landslide in which a 

block of rock or soil moves along a 

curved surface and rotates. 

Tsunami: a potentially destructive 

ocean wave created by an 

earthquake or other large-scale 

disturbance of the ocean floor; a 

seismic sea wave. This Japanese 

word has the same form in both the 

singular and the plural. 

PROCEDURE 

Teacher Preparation (optional but highly recommended)

If at all possible, gather a selection of local geologic and soil maps in 

advance. Make student copies of these maps or the appropriate portions 

of them. If you are not familiar with maps of this type, invite a local 

geologist or soil scientist to explain them. 

A. Introduction 

Have students read Master 2.5a, Background Reading: Site 

Characteristics, as homework, or read it with them in class. Explain and 

amplify any unfamiliar terms. Discuss the relationship between soils, 

subsoil geology, and the suitability of a site for building. Explain that 

the locations of roads, utility lines, reservoirs, and other facilities also 

involve seismic considerations. 

B. Lesson Development 

1. Divide students into small groups. Give each group one copy of 

Master 2.5c, Surface Map, Soil Map, Geologic Map, and Hazard Map 

(4 pages). Use the map keys to review the special symbols and 

markings on each map. Instruct students to interpret the information 

shown on the specialized maps and transfer it to the surface map. 

2. As a class, discuss what type of building would be most earthquake 

resistant in each area of the maps the groups have developed. Ask: Are 

there some areas where construction is not advisable no matter what the 

building materials? Instruct students to add these notations to the maps. 

3. When all the maps have been completed, site hazards have been 

noted, and construction recommendations have been made, regroup 

students into three or four large groups. Within each large group, students can quiz each other about the potential of various sites on their 

maps. 

4. Ask for a volunteer from each large group to report on the group’s 

findings and recommendations. Ask students: What would be the best 

way to share your recommendations if these maps represented your 

own area of the country? 

C. Conclusion 

Stack the three specialized maps on the projector at the same time so 

the various kinds of information are all displayed simultaneously. 

Discuss the conclusions that students have drawn and answer any 

questions. Extend the discussion to the geologic history and hazard 

potential of your own region. 

(optional but highly recommended) 

Direct students’ attention to the local map they prepared in Unit 1. 

Have them follow the process they used above to transfer information 

from local soil maps to the classroom map, noting any implications for 

building and the location of critical facilities. If this process arouses 

concerns about safety during an earthquake, ask students to contact the 

local officials they interviewed in Unit 1 to express their concerns and 

find out if these concerns have been taken into consideration. Ask these 

students to report back to the class on what they learn. V

AGU / FEMA 130 S EISMIC S LEUTHS
MASTER PAGE Teacher Background Reading 

Site Characteristics

2.5a 

“Earthquakes don’t kill people, buildings do.” 

Architects and engineers consider this a fair one-sentence summary of earthquake-related deaths, injuries, and 

damage. Yet, underneath every building is the Earth, which can shake and damage or destroy the building. In the 

final analysis, the cause of the death and destruction may not be the earthquake or the building, but rather 

someone’s lack of knowledge about the soil and subsoil under the building. Much of the scientific study 

surrounding earthquakes is focused on the geological characteristics of building sites, the relationship of building 

sites to earthquake damage, and how buildings respond to ground shaking induced by earthquakes. Location is 

just as important as building design for making sure that a building can survive an earthquake. Geological site 

considerations include the location and history of faults, sedimentary deposits, landfill, liquefaction, steep slopes 

and landslides, tsunami, and human-made hazards. 

Faults: Displacement and Ground Shaking 

Earthquakes happen when two sides of a fault are displaced, releasing energy in waves. Buildings can be 

damaged either by direct displacement on the fault or by ground shaking. 

Geologists have mapped the locations of many of the most dangerous fault zones in the U.S., yet many faults are 

not yet recognized. A building within a fault zone can be severely damaged by an earthquake on that fault, but 

this kind of damage is rare. Most buildings are not in fault zones, and the recurrence interval for any particular 

fault may be hundreds or thousands of years. The most common cause of damage in earthquakes is the ground 

shaking caused by the earthquake waves. These attenuate, or die off, with distance, so the two most important 

factors controlling the amount of shaking are the magnitude of the earthquake and the distance of the building 

from the fault. 

The distance from the fault, not from the epicenter, determines the amount of damage. Energy is produced by all 

the parts of the fault that move in an earthquake. Because in big earthquakes the fault can be hundreds of miles 

long, a structure may be hundreds of miles from the epicenter and still be on top of the quake’s impact zone. 

Several other factors can affect the amount of shaking. Waves do not travel evenly in all directions from the fault, 

so the orientation of the fault and the way in which displacement on the fault occurs can change the characteristics 

of the waves. Even more important are variations in local topography—the lay of the land—including the subsoil 

layers, which may trap or amplify seismic energy, and the type of rock and soil that underlie buildings. 

Sediments and Landfill 

Ground shaking is greatest on soil that has arrived in place fairly recently, whether it was put there by natural 

processes (in which case, geologists call it sediment) or by artificial ones (in which case, it is called landfill). 

Unfortunately, most of the world’s urban centers are sited on relatively young, loose, sedimentary deposits. 

Sediment age and particle size are important in predicting how soil will respond to shaking during an earthquake. 

Areas near the shores of rivers and oceans are especially likely to contain young sediments washed there by the 

water. 

Structures located on former watercourses (such as old river beds) or on sites that have been artificially filled with 

sand dredged up from the bottom of a body of water are among the worst locations for construction in earthquake 

country because the soil can shift so easily. In Mexico’s devastating 1985 earthquake, Mexico City, 320 km (200 

miles) from the epicenter, suffered far more damage than the shoreline towns closer to the epicenter. The 

shoreline is made of solid rock, but Mexico City is built on the sediments of an ancient lakebed. 

Old watercourses are usually low and wet, so they are frequently filled when someone wants new land to build on 

and sell. Landfill is usually a mixture of soil, rock, and decaying organic material in particles of varying sizes. 

AGU / FEMA 131 S EISMIC S LEUTHS
MASTER PAGE 

Because it is not natural to the area where it has been put, landfill in one spot is likely to be of a different 

composition from landfill in another spot nearby. When seismic waves are transmitted through landfill, they are 

amplified and their period is lengthened. Long earthquake waves are particularly destructive to some types of 

surface structures. Landfills commonly will settle and sink during a strong earthquake. 

Liquefaction 

Whenever poorly consolidated soil or fine sand becomes saturated, an earthquake is likely to cause soil 

liquefaction. Earthquake vibrations compact the soil, causing water mixed with sand to flow upward. Structures 

may settle several feet or even topple, causing considerable damage. In a related phenomenon, sandy or muddy 

soils may behave like liquids, flowing out onto the surface as sand boils or mud boils. 

Slopes and Landslides 

Structures on cliffs and ridges are also at high risk for earthquake damage, even if they are built on strong 

bedrock. Earthquake waves appear to be reflected and amplified by topographic highs like cliffs and ridges. 

Earthquakes also dramatically increase the potential for landslides in areas where landslides are common, such as 

those where sedimentary rocks lie just under the soil. The probability of an earthquake-related landslide depends 

on the strength of the slope materials, the steepness of the slope, and the extent and duration of ground shaking. 

Structures on cliffs and ridges need to be designed to the highest earthquake standards, and should be fully 

insured. 

Tsunami 

Tsunami are caused by faulting and the abrupt movement of the ocean floor during an underwater earthquake. A 

wave generated by this movement can travel as fast as 640 km/hr (400 mph) on the open ocean, where it may not 

be much above normal height. When it approaches the shore, however, it may attain a height of 15-20 m (50 

feet)—in some cases, even 32 m. Tsunami present a distinct hazard to low-lying coastal areas, particularly the 

west and northwest shorelines along the western North American coast and the northerly facing coast of Hawaii. 

Low-lying waterfront properties in these areas are at high risk from tsunami. 

Human-Made Structures 

Human-made structures, such as dams, reservoirs, water tanks, and tall buildings, can present special earthquake 

hazards, and need to be considered during site selection. Every building decision needs to consider the exposure 

to geologic hazard and the probability of an earthquake, bearing in mind that earthquakes are possible anywhere 

in the world at any time. 

AGU / FEMA 132 S EISMIC S LEUTHS
MASTER PAGE Soil and Geologic Maps 

and Map Sources

2.5b 

Q USGS topographical maps of your area 

Q Detailed USGS seismic maps that specifically identify earthquake fault traces (available only for areas of high 

seismic risk) 

Q Maps issued by state departments of geology or natural resources 

Q Land use policy or development maps, available from county or city zoning offices. The use of these maps is 

mandatory for all nonresidential and large-scale residential construction. They may be referred to as “special 

studies zones” maps 

Q Seismic risk maps. These are based on the location, number, and magnitude of historic earthquake events that 

have taken place and been recorded during the last 200 years 

Q Maps indicating areas of structurally defective grounds, generally developed by state or local agencies to 

include (a) poor soils and (b) landslide areas 

Q Landslide susceptibility maps, available from USGS for specific regions in the U.S. The U.S. Department of 

Housing and Urban Development also has data and maps of landslide problems. 

Q Maps noting geologic hazards; may he included in your local building codes 

Q Microzonation maps include data on the anticipated maximum earthquake intensity, active faults, geologic 

units, special studies zones, ground response, liquefaction susceptibility, landslide susceptibility, and zones of 

potential tsunami inundation. Available from zoning offices. 

Q Soil studies of the area produced for agricultural purposes, either by USDA or local agencies 

Q Soil maps produced by the Soil Conservation Service 

AGU / FEMA 133 S EISMIC S LEUTHS
AGU / FEMA 134 S EISMIC S LEUTHS
2.5c MASTER PAGE Surface Map

AGU / FEMA 135 S EISMIC S LEUTHS
MASTER PAGE Soil Map

AGU / FEMA 136 S EISMIC S LEUTHS
MASTER PAGE Geologic Map

AGU / FEMA 137 S EISMIC S LEUTHS
MASTER PAGE Hazard Map

AGU / FEMA 138 S EISMIC S LEUTHS
2 UNIT RESOURCES 

BOOKS FOR YOUNG READERS 

Asimov, I. (1978). How Did We Find Out about 

Earthquakes? New York: Walker. 

Aylesworth, T.G., and Aylesworth, V.L. (1983). 

Moving Continents—Our Changing Earth. Hillside, 

N.J.: Enslow. 

Eicher, D.L. (1976). Geologic Time. Englewood 

Cliffs, NJ. Prentice Hall. 

Eicher, D.L. (1984). The History of the Earth’s Crust. 

Englewood Cliffs, NJ: Prentice Hall. 

Fodor, R.V. (1978). Earth in Motion: The Concept of 

Plate Tectonics. New York: William Morrow. 

Iacopi, R. (1974). Earthquake Country. Menlo Park, 

CA: Lane Book Company. 

National Geographic Society. (1982). Our Violent 

Earth. Washington, DC: National Geographic Society. 

Poynter, M. (1990). Earthquakes: Looking for 

Answers. Hillside, NJ: Enslow. 

Walker, B. (1981). Earthquake. (Planet Earth series) 

Alexandria, VA: Time-Life Books. 

BOOKS 

Adams, M. W., editor. (1970). Tsunamis in the Pacific 

Ocean. Honolulu, HI: East-West Center Press. 

Bolt, Bruce A. (1993). Earthquakes. New York: W. H. 

Freeman and Co. General information on earthquakes 

in a readable style. Probably the best single source 

currently available. 

Bolt, Bruce, A. (1982). Inside the Earth. San 

Francisco: W.H. Freeman and Co. More technical than 

the later Earthquakes, but highly readable for adults 

and advanced students. Includes excellent historical 

information; portraits of Beno Gutenberg, Inge 

Lehmann, and other pioneers of seismology; plus 

challenging activities and exercises. 

Bonini, W.E., and Bonini, R.R. (1986). “Andrija 

Mohorovicic: Seventy Years Ago an Earthquake 

Shook Zagreb.” In History of Geophysics, Vol. 2, 

edited by C. Stewart Gillmor. Washington, DC: 

American Geophysical Union, pp. 83-88. 

Earthquake National Research Council. (1986). Active 

Tectonics. Washington, DC: National Academy Press. 

An anthology of technical discussions, part of the 

Studies in Geophysics series. 

Eiby, G.A. (1980). Earthquakes. Auckland, New 

Zealand: Heineman. 

Georgi, Johannes. (1934). Mid-Ice: The Story of the 

Wegener Expedition to Greenland. London, England: 

K. Paul, Trench, Trubner, and Co., Ltd. 

Gere, J.M., and Shah, H.C. Terra Non Firma: 

Understanding and Preparing for Earthquakes. New 

York: W.H. Freeman. 

Gubbins, David. (1990). Seismology and Plate 

Tectonics. New York: Cambridge University Press. An 

undergraduate textbook. Readable, with useful 

illustrations, many advanced math activities, and some 

60 seismograms. 

AGU / FEMA 139 S EISMIC S LEUTHS
UNIT RESOURCES 

Levin, H.L. (1978). The Earth through Time. 

Philadelphia, PA: W.B. Saunders. 

Moore, Gwendolyn B., and Yin, Robert K., 

(November 1984). Innovations in Earthquake and 

Natural Hazards Research: Determining Soil 

Liquefaction Potential. Washington DC: Cosmos 

Corporation (202-728-3939). 

Nance, John J. (1989). On Shaky Ground: America’s 

Earthquake Alert. New York: Avon Books. 

National Academy of Sciences. (1985). Liquefaction 

of Soils during Earthquakes. Washington, DC: 

National Academy Press. 

Federal Emergency Management Agency/National 

Science Teachers Association (NSTA)/FEMA. (1988). 

Earthquakes—A Teacher’s Package for K-6. FEMA 

159. Washington, DC: FEMA Publications (500 C St. 

SW, Washington, DC 20742). 

Oakeshott, G.B. (1976). Volcanoes and Earthquakes: 

Geologic Violence. New York: McGraw Hill. 

Pakiser, Louis. (1989). Earthquakes. Washington, DC: 

U.S. Government Printing Office. An illustrated 

pamphlet of general information, prepared for the U.S. 

Geological Survey, Department of the Interior. 

Scholtz, Christopher H. (1990) The Mechanics of 

Earthquakes and Faulting. Cambridge, England: 

Cambridge University Press. A technical reference for 

teachers interested in exploring further. 

U.S. Department of Commerce, Coast and Geodetic 

Survey. (1965). Tsunami! The Story of the Seismic Sea 

Wave Warning System. Washington, DC: U.S. 

Government Printing Office. An exciting story with 

fine illustrations, at a student’s reading level. 

Wegener, Alfred (1966). The Origin of Continents and 

Oceans. New York: Dover. 

Wegener, Else. (1939). Greenland Journey: The Story 

of Wegener’s German Expedition to Greenland in 

1930-1931. London and Glasgow: Blackie and Son 

Ltd. 

ARTICLES AND PAPERS 

Evaluating Earthquake Hazards in the Los Angeles 

Region—An Earth Science Perspective. U.S. Geologic 

Survey Professional Paper #1360, 1985, pages 

375-413, “Evaluating Tsunami Potential.” 

Gore, R. (1985). “Our Restless Planet Earth.” National 

Geographic 168: 142-181. Includes map, “Earth’s 

Dynamic Crust.” 

Lowman, P.; Wilkes, Y,; and Ridky, R.W. (1978). 

“Earthquakes and Plate Boundaries.” Journal of 

Geological Education 26: 69-72. 

Matthews, Samuel, W. (1973) “This changing Earth.” 

National Geographic 143: 1-37. 

McCredie, Scott. (March 1994). “Tsunami: The Wrath 

of Poseidon.” Smithsonian Magazine 24, 12:28-39. 

Peterson, Ivars. (Oct. 12, 1985). “Liquid Sand.” 

Science News. 

U. S. Geological Survey, 904 National Center, Reston, 

Virginia, 22092; 703/648-6078. See especially 

“Pacific Tsunami Warning System,” Volume 18, 

Number 3, 1986, and “Devastating Tsunami Inspires 

Efforts to Reduce Future Tsunami Destruction,” 

Volume 19, Number 2, 1987. 

Wilson, J.T., ed. (1970). Continents Adrift: Readings 

from Scientific American. New York: W.H. Freeman 

and Co. 

NONPRINT MEDIA 

California Earthquake Education Project. Earthquake 

kits and group materials. Lawrence Hall of Science, 

University of California, Berkeley, CA 94720; 

415/327-6017. 

The Drift Globe. Burlington, NC: Omni Resources, 

Inc. (919/227-8300). A 12"-diameter globe with velcro 

fasteners and velcro continents. Instruction guide is 

illustrated with cartoons. 

The Earthquake Connection. A live-action video in 

two parts. Available from Ward’s Natural Science 

Establishment, Inc., 5100 W. Henrietta Road, PO Box 

92912, Rochester, NY; 800-962-2660. Ward’s also has 

earthquake filmstrips and slides. 

Earthquake Effects: A Computer Animation and Paper 

Model. U.S. Geological Survey Open-File Report 

92-200B, by Tau Rho Alpha, Robert A. Page, and 

Leslie C. Gordon. Order from U.S. Geological Survey, 

PO Box 25425, Denver, CO 80225; 303-236-4476. 

AGU / FEMA 140 S EISMIC S LEUTHS
UNIT RESOURCES 

Earthquake Simulator. A program for the Apple II 

series. Available from Ward’s Natural Science 

Establishment, Inc., 5100 W. Henrietta Road, PO Box 

92912, Rochester, NY; 800-962-2660. 

Earthquake Slides. Photographs of earthquake effects, 

copies of seismograms, and seismicity maps can be 

obtained from the National Geophysical and Solar 

Terrestrial Data Center, Code D62, NOAA/EDS, 

Boulder, CO 80302. 

Earthquake Sounds. A cassette tape of sounds 

recorded in various earthquakes, available with a 

catalog from Seismological Society of America, 201 

Plaza Professional Building, El Cerrito, CA 94530; 

415-525-5474. 

Earthquakes: Environments and Effects. A 15-minute 

interactive videotape available from CALEEP, 510-

642-8718. 

EERI Videotapes and Slide Sets. Oakland, CA: 

Earthquake Engineering Research Institute. For 

information, phone 510-451-0905, or fax 510-451-

5411. 

Steinbrugge Collection. Richmond, CA: Earthquake 

Engineering Research Center. Over 10,000 

photographs and 5,000 slides of earthquake damage. 

The library will provide copies to teachers and 

researchers. Call 510-231-9401 for information. 

Note: Many of the references for Unit 3 may also be useful 

for teaching this unit. Inclusion of materials in these 

resource listings does not constitute an endorsement by 

AGU or FEMA. 

AGU / FEMA 141 S EISMIC S LEUTHS
AGU / FEMA 142 S EISMIC S LEUTHS
UNIT THREE 
3 INTRODUCTION 

In the first lesson, students will learn about the 

movement of earthquake waves in our Earth and on its 

surface. It was the study of this movement, by 

Mohorovicic, Lehmann, and others, that developed 

our current understanding of the interior of the Earth. 

Activities illustrate the movement of P and S waves. 

Background material on Love and Rayleigh waves is 

also provided. 

The second lesson in Unit 3 is built around 

biographical sketches of three individuals who made 

major contributions to our knowledge of the Earth’s 

inner structure: the German meteorologist Alfred 

Wegener, who amassed evidence for the controversial 

theory of continental drift; the Croatian seismologist 

Andrija Mohorovicic, who demonstrated the existence 

of the discontinuity between crust and mantle that 

bears his name; and the Danish seismologist Inge 

Lehmann, who demonstrated the existence of the inner 

core. A timetable of other relevant discoveries is 

included as teacher background material. 

Lesson 3 begins with a pair of activities that contrast 

the two systems most commonly used to characterize 

earthquakes—the Modified Mercalli scale, which 

assigns a number on the basis of observed effects, and 

the Richter scale, which assigns a number on the basis 

of instrument readings. Students draw isoseismals on a 

map in the first activity. In the second they compare 

Richter magnitudes from several seismograph stations 

for the same earthquake. In the third activity, they 

practice reading seismograms. 

Lesson 4 has three parts, moving from the worldwide 

distribution of earthquakes to one seismically active 

area of Japan and then home to the United States. At 

all three stages, students plot actual earthquake data in 

order to gain an experiential understanding of where 

earthquakes occur. In the second activity they 

construct a plot in three dimensions. Most students 

will be surprised to learn that earthquakes are 

everyday occurrences on a global scale, and that they 

may originate from foci as deep as 700 km inside the 

Earth—1/9 of the way to its center. 

Like the previous unit, this one offers a variety of 

experiences in scientific observation, computation, and 

the application of social science principles. It also 

presents factual information that will stand students in 

good stead as consumers of media information and as 

future property owners. 

Social studies teachers may be especially interested in 

the second lesson of this unit. Mathematics teachers 

will find applications of algebra and geometry in many 

of the others. The lessons in this unit can stand on their 

own, but taken together, they provide an excellent 

preparation for learning to mitigate the effect of 

earthquakes on the human environment, in Unit 4. 

AGU / FEMA 142 S EISMIC S LEUTHS
3.1 

RATIONALE 

To understand earthquakes and their effects on Earth’s surface, and to 

understand how scientists have learned about Earth’s interior, students 

must begin to understand the properties of waves. 

FOCUS QUESTIONS 

How does matter transmit energy in the form of waves? 

TEACHING CLUES AND CUES 

Metal Slinkies will be 

more effective than 

plastic ones for this 

activity. If you use plastic 

OBJECTIVES 

Students will: 

1. Compare and contrast the two main types of earthquake waves and 

draw sketches to illustrate them. 

2. Describe the manner in which each of the two types transfers energy 

and moves Earth particles. 

Slinkies, tape two together, with 

about 7.5 cm of overlap, for each 

pair of students.

PART ONE 

PRIMARY WAVES (P WAVES) 

MATERIALS 

It will be helpful to refer 

to Master 2.2b, Earth 

Cross Section, as you 

talk about waves moving 

QStudent copies of Master 3.1a, Earthquake Wave Background 

QSlinky toys (One for every two students is ideal.) 

QWhite plastic tape 

QString 

QUnlined paper 

QPencils 

PROCEDURE 

Teacher Preparation 

Put the Slinky toys and the tape in a central location where they will 

be available to students. Students will mark the coils so they can see 

the movement of energy along their length. 

through the Earth. You may want to 

project the transparency. 

AGU / FEMA 143 S EISMIC S LEUTHS
VOCABULARY 

Body waves: waves 

that move through the 

body (rather than the 

surface) of the Earth. 

A. Introduction 

Explain: It is the energy from earthquakes that puts human beings and 

human structures in danger. This energy is transmitted through the 

Earth in the form of waves. Distribute copies of Master 3.la, 

Earthquake Wave Background. Go over the Body Waves section of 

the background material with the class. 

B. Lesson Development 

1. Ask students: 

Q Where is the energy of an earthquake released? (along the fault 

plane where tectonic stress is released) 

Q In what form is the energy from an earthquake released? (in the 

form of waves) 

2. Divide students into pairs or groups of even numbers, depending on 

the number of Slinkies available. Direct students to pick up their 

Slinkies and mark two spots on each, near the center of the coil, with 

white plastic tape. The two pieces of tape should be at the tops of 

adjacent loops. 

3. Two students will hold each Slinky, one on either end. Instruct them 

to stretch it out to a length of approximately three meters on the floor 

or a long counter. Have students take turns compressing between 10 

and 20 coils and then releasing them rapidly while they continue to 

hold the Slinky. 

P waves and S waves are body 

waves. 

Compression: squeezing, being 

made to occupy less space. P waves 

are also called compressional waves 

because they consist of alternating 

compressions and expansions. 

Longitudinal waves: waves that 

move particles back and forth in the 

some line as the direction of the 

wave (P waves). 

P waves: primary waves, arrive at a 

station first because they travel 

faster than S waves, or secondary 

waves. These waves carry energy 

through the Earth in the form of 

longitudinal waves. 

S waves: secondary waves; waves 

that carry energy through the Earth 

in the form of very complex patterns 

of transverse waves. These waves 

move more slowly than P waves (in 

which the ground moves parallel to 

the direction of the wave). In an 

earthquake S waves are usually 

bigger than Ps. 

Transverse waves: waves that 

vibrate particles in a direction 

perpendicular to the wave’s direction 

of motion (S waves). 

TEACHING CLUES AND CUES

4. After several repetitions, ask students to describe what they saw 

happen with the coil and the tape. Then ask: 

Activity 3 in lesson 2.4 

deals with tsunami, 

destructive water waves 

often caused by earthQ What kind of earthquake waves does this movement resemble? 

(longitudinal body waves, or P waves) 

quakes. If you have not taught this 

lesson, refer to it now. 

Q How is the movement of the spring like the movement of the 

waves? (It moves by contracting and expanding—by compression 

and expansion.) 

AGU / FEMA 144 S EISMIC S LEUTHS
Q In what direction does the energy move? (It moves out from the TEACHING CLUES AND CUES 

point at which the energy is released—the focus.) Point out that in a P 

wave the movement of 

each coil of the Slinky is 

parallel to the wave 

Q What happens within the body of the Earth when energy moves 

through it in this way? (Energy is transmitted from any material 

near the focus to particles away from the source in the form of 

waves.) 

C. Conclusion 

Challenge pairs of students to decide what a P wave would look like 

and draw one on the top half of a sheet of paper. Tell them to use 

pencil, so if they change their minds later they can revise the drawing. 

(There are several acceptable ways to do this.) 

ADAPTATIONS AND EXTENSIONS 

1. With students who show special interest, assign all of the reading 

on Master 3.1a and add Rayleigh waves and Love waves to your 

discussion. 

2. Research and discuss (a) the intermolecular forces that provide the 

means of transmitting energy in longitudinal waves and (b) the speed 

of P waves traveling in the Earth’s crust. Ask: 

motion (the length of the Slinky). In 

an S wave, the movement is 

perpendicular to the length of the 

Slinky. This difference may be easier 

for students to see than compression 

and dilation. 

Q How does the density of materials affect the speed of P waves? 

(The more dense the material, the faster the waves move.) 

Q As P waves travel deeper into the Earth, does their speed change? 

(P waves, like S waves, move faster in the mantle than in the crust, 

because the mantle is more dense. The rocks that compose the Earth 

at great depths, however, are plastic, so they slow down the waves.) 

Q Why can P waves travel through liquids, while S waves cannot? (P 

waves travel by compression, and S waves travel by shearing at 

right angles to the direction of motion. Water cannot spring back 

after it is sheared, so the S waves die out in water.) 

Q How are P waves similar to sound waves? (A sound wave in the 

ground is a P wave; a P wave in the air is a sound wave. Both are 

compressional waves.) 

PART TWO 

SECONDARY, OR SHEAR WAVES (S WAVES) 

MATERIALS 

Q 7.6 m (25 ft) of coiled telephone cord, available at electronics or 

phone stores and some discount stores 

Q Two different colors of plastic tape, about 1 cm (.5 in.) wide 

Q Masking tape 

Q Two empty soda cans 

AGU / FEMA 145 S EISMIC S LEUTHS
PROCEDURE TEACHING CLUES AND CUES 

A. Introduction 

Ask students: 

Q What type of body wave did the Slinky exercise illustrate? (P 

Students may be confused by the array of 

synonyms for P waves 

and S waves. Help them 

waves, also known as compressional waves or longitudinal waves) 

Q What is the other type of body wave? (S waves, also known as 

waves or transverse waves) 

B. Lesson Development 

1. Give these instructions for demonstrating single shear waves (S 

waves). 

a. Place a band of bright colored tape halfway along the coiled 

telephone cord. Place another band close to one end. Lay the cord 

straight along a smooth surface. Have two students hold the ends of 

the cord firmly so it will not move. 

b. With plain masking tape, mark a 50-cm line perpendicular to one 

end of the cord. Mark another line of the same length at the cord’s 

halfway point, directly under the center band of tape. This will provide 

you with a reference line. 

c. Pick up the end of the rope at the center of the first perpendicular 

tape line, then move your hand back and forth quickly along the 

masking tape. As you expected, a wave travels down the rope (or 

transmitting medium). Observe the motion of the colored tape while 

waves are moving by. Students may take turns holding the ends of the 

cord. 

to understand that each term provides additional information about 

one type of wave. P waves, or 

primary waves, are also called 

compressional waves and longitudinal waves. S waves, or secondary 

waves, are also called shear waves 

and transverse waves. Both P and S 

waves are body waves. 

AGU / FEMA 146 S EISMIC S LEUTHS
d. Place two empty soda cans upright on either side of the cord on the 

center tape line. Both cans should be the same distance from the 

cord—about 30 cm (1 ft). When a wave of sufficient amplitude is sent 

along the cord between these cans, what will happen? (The same piece 

of cord, as indicated by the colored tape marker, will knock over both 

cans.) 

2. Point out that although students may only see motion in one 

direction, the transverse wave they have just observed vibrates in a 

direction perpendicular to its direction of motion. Remind students 

that S waves within the Earth are not just in one plane, and don’t all 

have the same frequencies and amplitudes. In an earthquake, a jumble 

of S waves passes through a particular volume of Earth at the same 

time. Since S waves reach the surface from below, a special pendulum 

seismograph would show ground motion for S waves as a very 

complex, seemingly random pattern of horizontal (back and forth) 

motions. 

C. Conclusion 

Ask students: 

Q Which type of wave does this activity illustrate? (S waves) 

Q What are some differences between P waves and S waves? (P 

waves are longitudinal and S waves are transverse. P waves can be 

transmitted through solids, liquids, and gases, while S waves can 

only be transmitted through solids.) 

Now ask students, working in the same pairs as for part one, to decide 

what a diagram of an S wave would look like and draw one on the 

other half of the page they used in part one. They may want to revise 

their drawings of a P wave at this time. When they have finished, ask 

each pair of students to exchange their drawings with another pair and 

discuss the similarities and differences. 

ADAPTATIONS AND EXTENSIONS 

1. If students have also discussed Rayleigh waves and Love waves, 

ask them to draw these on the backs of their pages at this time and 

follow the procedure for exchanging diagrams as above. 

2. Invite students to research and discuss the intermolecular forces that 

provide the means of transmitting energy in transverse waves, and 

why S waves can not be transmitted through liquids, including Earth’s 

outer core. V

AGU / FEMA 147 S EISMIC S LEUTHS
AGU / FEMA 148 S EISMIC S LEUTHS
3.1a MASTER PAGE Earthquake Wave Background 

The major types of seismic waves are classified as 

body waves and surface waves. The two have 

different shapes and properties. All waves in matter 

depend upon the interaction of forces among the 

particles of some material. These forces transmit 

movement of one particle to movement in adjacent 

particles. 

Body Waves 

Body waves, so called because they travel through 

the body of the Earth, consist of two types: primary 

(P) and secondary (S). S waves are also called shear 

waves and transverse waves. 

Primary (P) waves consist of alternating 

compressions and expansions (dilations), so they are 

also referred to as compressional waves. P waves are 

longitudinal; they cause particle motion that is back 

and forth, in the same linear direction as energy 

transfer. These waves carry energy through the 

Earth, usually at the rate of 3.5–7.2 km/sec in the 

crust and 7.8–8.5 km/sec in the mantle. 

Secondary (S) waves are transverse; the particle 

motion they cause is perpendicular to the direction 

of energy transfer. Their usual speed is 2.0–4.2 

km/sec in the crust and 4.5–4.9 km/sec in the mantle. 

Longitudinal (P) waves can be transmitted through 

solids, liquids, and gases, while transverse (S) waves 

(with the exception of electromagnetic waves) can 

only be transmitted by solids. Waves can be 

reflected and refracted (bent) when they move from 

material of one density to that of another density. 

Wave energy can also be changed to other forms. As 

they move through the Earth, the waves decrease in 

strength, or attenuate. Waves attenuate more slowly 

in solid rocks than in the basins full of sediment so 

common in the West. Because of this, an earthquake 

in the crust of the eastern United States is felt over a 

wider area than a quake the same size in the rocks of 

the western states. 

Surface Waves 

Seismograph stations detect surface waves from 

many, but not all, quakes. Whether a station detects 

them or not depends on the strength of the quake’s 

energy release, the depth of the quake, and the 

station’s distance from the focus. 

AGU / FEMA 149 S EISMIC S LEUTHS
MASTER PAGE 

Unlike body waves, which travel through the Earth, 

surface waves travel around it. The two main types of 

surface waves are called Rayleigh waves and Love 

waves. These surface waves travel more slowly than S 

and P waves, and attenuate more quickly. 

Within Rayleigh waves, Earth particles move in 

elliptical paths whose plane is vertical and set in the 

direction of energy transfer. When an Earth particle is 

at the top of the ellipse, it moves toward the energy 

source (seemingly backwards), then around, 

downward, and forward, away from the source. It then 

moves around and upwards back to its original 

position. This produces a ripple effect at the Earth’s 

surface that is similar to ripples on a pond. The orbits, 

or paths, of these particles become smaller and finally 

die out at a certain depth within the Earth. 

Love waves move particles in a back and forth 

horizontal motion as the energy moves forward. If you 

could see a Love wave inside the Earth, you would 

notice a zigzag horizontal motion. 

Putting Them Together 

Since these four types of waves shake a location on 

Earth’s surface in various ways and directions, a 

seismic station needs at least three seismographs to 

glean a reasonably good image of ground shaking at 

that location. One seismograph is built to measure 

vertical motions, and two others, aligned perpendicular 

to each other, measure horizontal motions. Although P, 

S, and Rayleigh waves may be recorded on all three 

seismographs, P waves are best recorded on the 

vertical component and S waves on the horizontal. 

Love waves are only recorded on the horizontal 

components, but Rayleigh waves are recorded on all 

three. 

AGU / FEMA 150 S EISMIC S LEUTHS
3.2 

Pioneering Ideas 

VOCABULARY

Continental drift: the 

theory, first advanced by 

Alfred Wegener, that 

Earth’s continents were 

RATIONALE 

The people who have shaped our idea of the Earth are pioneers, just as 

truly as those who struck out in new directions across its surface. This 

idea may be new to students. 

FOCUS QUESTIONS 

Could a person be a pioneer without leaving home? 

OBJECTIVES 

Students will: 

1. Read a biographical sketch about a pioneer of earth science. 

2. Identify the characteristics of a pioneer. 

3. Be able to tell why Wegener, Mohorovicic, and Lehman were 

pioneers. 

MATERIALS

Q Student copies of Master 3.2a, Three Pioneers (3 pages) 

Q Master 3.2b, Chronology: The Beginnings of the Seismological Age 

Q Overhead projector and transparencies (optional) 

Q Reference books for research (See Unit Resources.) 

Q Paper and pens 

PROCEDURE 

Teacher Preparation 

Assemble a classroom reference shelf of biographical encyclopedias, 

studies on continental drift and plate tectonics, and books on earthquakes. (See Unit Resources.) 

A. Introduction 

Tell students that you would like them to explore the notion of 

pioneer. Write the word on the chalkboard or overhead projector and 

ask the class to brainstorm about the meaning of the word and its 

implications. Be prepared to accept any reasonable suggestion. Such 

ideas as risk-taker, adventurer, initiator, innovator, frontier person, and 

explorer are likely to come forward. You may want to use these terms 

to build a concept map. 

originally one land mass, split off and 

gradually form the continents we 

know. 

Epitaph: an inscription on a 

tombstone, often intended to sum up 

the achievements of a person’s life. 

Meteorology: the study of Earth’s 

atmosphere. 

Pioneer: a person who moves into 

new and uncharted territory. 

Plate tectonics: the theory that 

Earth’s crust and upper mantle (the 

lithosphere) are broken into a 

number a more or less rigid, but 

constantly moving, segments, or 

plates. 

Seismology: the scientific study of 

earthquakes. 

Topography (adj. topographic): 

the shape of the land; the contours 

and the arrangement of surface 

features that characterize a region.

AGU / FEMA 151 S EISMIC S LEUTHS
During the course of the brainstorming, remind the class that in a 

historical sense, we tend to think of pioneers as men and women who 

have moved beyond the edge of settlement. Daniel Boone was such a 

person, and so were Lewis and Clark and Matthew Henson, the polar 

explorer. There are other types of pioneers, however—those who are 

willing to advance new ideas and suggest new theories to explain 

physical or cultural phenomena. Albert Einstein, with his theory of 

relativity, is a good example of this kind of pioneer. So is Marie Curie, 

who worked to develop radium therapy and conducted some of the 

earliest experiments with radiation. 

B. Lesson Development 

1. When the brainstorming session has ended, ask each student to 

write a one-sentence definition of the term pioneer, using the list 

generated by the class as a reference. Then have students share their 

responses to learn if a consensus has developed about the meaning of 

the term. From the collection of definitions presented by class 

members, write what seems to be a representative definition on either 

the board or the overhead. Here are some likely definitions: 

A pioneer is a person who is on the cutting edge, someone with the 

courage and the vision to try something new. 

A pioneer is the first person to suggest a new idea or to try something 

that has never been tried before. 

A pioneer is a person who prepares the way for others because of 

his/her courage and foresight. 

TEACHING CLUES AND CUES

Use Master 3.2b, 

Chronology: The 

Beginnings of the 

Seismological Age, for 

2. Divide the class into groups of three students each. Provide each 

group with one copy of Master 3.2a, Three Pioneers. Each of the 

students may read one essay. When students have finished reading, 

ask them to give the essay a title and to write a two- or three-sentence 

summary of the essay in the space provided. 

3. With this as context, remind students that when each of these 

discoveries was first published, it created discussion and even 

controversy. To understand the kind of excitement each advance in 

science causes, have half of the students who read about each scientist 

research the evidence that person offered to support the new theory 

and the other half research the views of his or her critics or the reasons 

why it may not have been accepted immediately. Later in the same 

period or the next day, invite the groups to present and discuss 

opposing points of view culled from their reading. 

C. Conclusion 

Return to the consensus definition of pioneer that the class developed 

and ask students to apply that definition to these three individuals. To 

do this, they should write epitaphs for the tombstones of the three 

scientists. Remind students that the purpose of an epitaph is to 

summarize a person’s life in a brief and pithy fashion. Post the 

epitaphs on the bulletin board to present the variety of impressions 

class members have about Wegener, Mohorovicic, and Lehmann. 

your own reference and to help 

students place the work of these 

three scientists in the context of 

other disAGU / FEMA 152 S EISMIC S LEUTHS
ADAPTATIONS AND EXTENSIONS 

1. Make a time line from the information on Master 3.2b, Chronology: 

The Beginnings of the Seismological Age. You could do this either 

before class or during class with student participation. 

2. As a class, brainstorm suitable epitaphs for some of the other 

pioneers mentioned in this lesson and those students know about from 

other areas of study. 

3. Encourage students to read biographies of intellectual explorers and 

learn about some of the challenges pioneers have faced. V

AGU / FEMA 153 S EISMIC S LEUTHS
AGU / FEMA 154 S EISMIC S LEUTHS
3.2a MASTER PAGE Three Pioneers

Name __________________________________________________________ Date ____________________ 

1. In 1912, when Alfred Wegener proposed in print that Earth’s 

continents floated on denser and more stable material below, he 

was openly ridiculed and even scorned by his colleagues. Not until 

several decades later did his ideas receive any acceptance. Today 

he stands as the forefather of modern plate tectonics because of his 

theory of continental drift. His widely accepted theory of land 

displacement holds that Earth’s continents have been in motion 

throughout geological time. 

Wegener believed that there was once a single supercontinent, 

which he called Pangea (or Pangaea). He said that Pangea broke 

apart millions of years ago to form two large continents. He called 

the one in the northern hemisphere Laurasia and the one in the 

southern hemisphere Gondwanaland. After a very long span of 

centuries, Wegener said, Laurasia split to form North America, 

most of Asia, Greenland, and a large section of Europe. 

Gondwanaland became Africa, South America, Australia, India, 

and Antarctica. Wegener believed that the land masses drifted for 

millions of years before assuming their present shapes and arriving 

at their present locations. He was led to this notion by the 

congruity he observed in the shorelines of the lands bordering the 

Atlantic Ocean and several other kinds of evidence. Further, he 

said, the process of continental drift is still going on—the 

continents are still on the move. 

Alfred Wegener, who was educated to be a meteorologist and an 

Arctic climatologist, insisted that his theory was correct because 

of the evidence he saw. To support his ideas about continental 

drift, Wegener pointed to the similarities in the fossils of the 

southern 

continents. Fossils of the same sort from ferns and freshwater 

reptiles had been found in all of the southern continents. He saw 

this as evidence that all the lands south of the equator has once 

been part of a single land mass. He argued that such land-based 

life forms could never have crossed the thousands of miles of open 

ocean that now separate these land masses. His critics scoffed 

because the physical model that Wegener proposed to explain the 

movement of continents did not fit what was then known about the 

physics of the Earth. 

For the next 30 years or so, scientists paid little attention to 

Wegener’s theory. In the 1960s, however, geologists discovered 

that the ocean floors had been spreading, thus influencing the 

shapes and sizes of the continents. This new theory, called plate 

tectonics, provided a mechanism that made sense in physical terms 

to account for Wegener’s idea of continental drift. 

Although the continents themselves do not drift, as Wegener 

proposed, he was correct in his thesis that Earth’s surface is not 

fixed. He was a man well ahead of his time whose insight went 

beyond safe and conventional thinking. So important is Wegener 

to our current understanding of plate tectonics that in the 1970s a 

crater on the dark side of the moon was named for him, to honor 

his courage and vision. 

Tragically, Alfred Wegener never lived to see his ideas accepted 

by the scientific community. He perished while attempting to cross 

Greenland from a camp on the ice cap in the winter of 1930. His 

purpose was to learn more about atmospheric conditions in the 

Arctic in order to better predict world weather patterns. 

What title would you give this essay? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

Write a two- or three-sentence summary of the essay, then add a one-sentence comment. 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

AGU / FEMA 155 S EISMIC S LEUTHS
MASTER PAGE 

Name __________________________________________________________ Date ____________________ 

2. “In the earth’s interior, where seismic waves travel invisibly and inaudibly, they can be followed only by mathematical equations.” 

Dragutin Skoko, Mohorovicic’s biographer 

The boundary separating Earth’s crust from its upper mantle is 

called the Mohorovicic discontinuity, or the Moho, for short, in 

honor of the Croatian seismologist Andrija Mohorovicic. In 1909, 

he used data on the travel tame of earthquake waves to 

demonstrate that their velocity changes at about 50 km beneath the 

surface. Others later refined the study of crust and upper mantle 

and applied new, methods, but Mohorovicic paved their way. 

Mohorovicic’s father, also named Andrija (or Andrew), was a 

maker of anchors. The young Mohorovicic loved the sea, and 

married a sea captain’s daughter. He taught for nine years at the 

Royal Nautical School in Baka. After becoming director of the 

Meteorological Observatory in Zagreb, in 1891, he studied and 

wrote primarily about clouds, rainstorms, and high winds. After a 

severe earthquake in 1901, however, Mohorovicic and his 

colleagues petitioned their government to establish a seismic 

station in Zagreb. In 1910, Mohorovicic published his account of 

the earthquake of November 9, 1880. In it, he plotted a nowstandard transit time graph-arrival time versus epicenter distance 

to recording station-using the data for 29 stations that ranged to a 

distance of 2,400 km from the epicenter. 

After plotting data for a large number of earthquakes over a wide 

area, he had begun to notice that the P wave arrivals required two 

curves on his graph. Because it was not possible to have P waves 

traveling in the same medium at different velocities, and the 

earlier P arrivals were only seen at some distance from the 

epicenter, he reasoned that the two (different arrival times 

represented two different phases of P waves traveling different 

paths. After working out the refraction equations and tests to 

determine optimal values for the depth of the focus, the ray paths 

of the two P waves, the corresponding two S phases, and their 

reflection paths, he concluded that at approximately 50 km there 

must be an abrupt change in the material that composes the 

interior of the Earth, because he observed an abrupt change in the 

velocity of the earthquake waves. Although this conclusion was 

not accepted immediately, Beno Gutenberg was able to confirm it 

with his own research as early as 1915. 

Even after earthquakes became one of his primary interests, as 

chief of the observatory, Mohorovicic was responsible for 

recording all the meteorological data for Croatia and Slovenia—

precipitation, tornadoes, whirlwinds, thunderstorms, and more—

with only an occasional assistant. He was responsible for all the 

mathematics involved in keeping records and for answering 

hundreds of letters and requests for assistance, as well as teaching 

classes at the University. He was patient and precise in his 

collection and analysis of data, but he loved good scientific 

instruments, and was frequently frustrated at the inadequacy of the 

instruments available and the difficulty of obtaining new ones. An 

accurate clock was particularly important to his research, because 

in studying earthquakes, an error of one second in the time of 

arrival means an error of 5.6 km in estimating the length of its 

travel making it impossible to accurately locate the focus of an 

earthquake. By 1913 he had finally obtained a crystal clock with a 

radio receiver that allowed him to synchronize with the Paris 

Observatory, but in 1914, during World War I, the army 

commandeered it for military use. When the dock was returned to 

him after the war, he also received a new radio receiver that took 

two railroad cars to transport. 

Mohorovicic published a paper in 1909 on the effect of 

earthquakes on buildings that described periods of oscillation (see 

lesson 4.3). In this he was at least 50 years ahead of the times both 

in his own country and elsewhere. Croatia’s first national 

Provisional Engineering Standards for Construction in Seismic 

Areas were published in 1964. 

During his lifetime, Mohorovicic maintained contacts with 

seismologists all over the world. He retired in 1922, but remained 

active until shortly before his death in 1936. His only grandchild, 

Andre, remembers that he was always good natured—a kind and 

peaceful man. Mohorovicic, like Alfred Wegener, received the 

honor of having his name given to a crater on the dark side of the 

moon. 

What title would you give this essay? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

AGU / FEMA 156 S EISMIC S LEUTHS
MASTER PAGE 

Write a two- or three-sentence summary of the essay, then add a one-sentence comment. 

AGU / FEMA 157 S EISMIC S LEUTHS

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 
MASTER PAGE 

Name __________________________________________________________ Date ____________________ 

3. By 1936, scientists had learned from the study of earthquake 

waves that the Earth has three layers, crust, mantle, and core. 

Denmark’s Inge Lehmann was the first to demonstrate the 

existence of a change in composition midway through the core, 

dividing it into an inner core and an outer core. This division is 

now known as the Lehmann discontinuity. 

As a girl, at the turn of the century, Lehmann attended the first 

coeducational school in Denmark, which was founded and run by 

Hanna Adler. (Adler’s nephew, Neils Bohr, was the first to 

describe the physical makeup of the atom.) At that school, 

Lehmann wrote many years later, “No difference between the 

intellect of boys and girls was recognized—a fact that brought me 

disappointments later in life when I found that this was not the 

general attitude.” 

Lehmann studied at Oxford, earned a master’s degree in 

mathematics from the University of Copenhagen, and went to 

work as an actuary, calculating life expectancies and statistical 

risks for insurance companies. Beginning in 1925, however, she 

also served as a staff member of the Danish Geodetic Institute, 

helping to establish seismological stations in Greenland and in 

Copenhagen—a part of the world not noted for its seismicity. 

Seismology soon became her life work, and for 25 years, until just 

before her retirement, she was the only Danish seismologist. 

As early as 1910 scientists had noticed a shadow zone in the 

Earth’s interior, but seismographs had not been refined enough to 

explain this observation. In the course of the 1930s more and more 

sensitive seismographs were being developed. At the Copenhagen 

Seismological Observatory, Lehmann studied waves reflected 

through the core from earthquakes in Japan. In 1936, after 10 

years of studying seismograms, she interpreted the newly 

revealed data to confirm the existence of a relatively small inner 

core in the center of the Earth. The paper in which she reported 

her findings has one of the shortest titles in the history of 

seismology, if not of all science: It was called “P.” 

Lehmann was among the founders of the Danish Geophysical 

Society in 1936, and served as its president from 1941 until 1944. 

She helped to formulate the constitution of the European 

Seismological Federation and was elected its first president in 

1950. She found time to attend most of the meetings of the 

International Union of Geodesy and Geophysics, and served on 

the executive committee of the International Seismological 

Association from 1936 to 1944, from 1951 to 1954, and from 

1957 to 1960. International cooperation in the sciences was one 

of her passions. She was active in national and international 

scientific organizations, and traveled in France, the Netherlands, 

Belgium, and Germany, where she worked with some of the 

leading seismologists of the day. In Canada, she worked at 

Ottawa’s Dominion Observatory, and in the United States she 

conducted research at the Seismological Laboratory, California 

Institute of Technology; the University of California at Berkeley; 

and the Lamont-Doherty Geological Observatory, Columbia 

University, New York. 

She loved hiking, skiing, and mountain climbing. Her favorite 

place indoors, aside from her own cottage in Denmark, was an art 

gallery. She loved to visit galleries and look at paintings 

whenever she traveled, and she traveled widely, especially after 

her retirement in 1953. She also loved music and gardening. Inge 

Lehmann died in February, 1993, at the age of 105, leaving a 

worldwide network of friends. 

What title would you give this essay? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

Write a two- or three-sentence summary of the essay, then add a one-sentence comment. 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

AGU / FEMA 158 S EISMIC S LEUTHS
AGU / FEMA 159 S EISMIC S LEUTHS
MASTER PAGE Chronology: 

The Beginnings of the Seismological Age 

3.2b 

Q1883: The English seismologist John Milne hypothesized that with the proper 

equipment, it should be possible to detect seismic waves from a large earthquake 

occurring anywhere on Earth. 

Q1889: Milne’s 1883 hypothesis was proven correct when E. von Rebeur 

Paschwitz used delicate pendulum seismographs to record the April 18, 1889, 

Tokyo earthquake in Potsdam and Wilhemshaven, Germany. 

Q1897: Richard Dixon Oldham noticed that seismograms from earthquakes 

consistently showed three different disturbances, the first and second 

“preliminary tremors” (now known as P waves and S waves, respectively) and 

the “large waves” that followed the preliminary tremors, and that the difference 

in arrival time between the “large waves” and the “preliminary tremors” 

increased in a predictable fashion with increasing distance from the earthquake. 

Q1900: Oldham established that the “preliminary tremors” (P and S waves) have 

travel paths that take them through the body of Earth (we now call them body 

waves), and that the “large waves” (now called surface waves) travel along 

Earth’s surface. 

Q1906: Oldham used evidence from earthquake waves to demonstrate the 

existence of a large central core at a depth of about 3,821 km beneath the surface. 

Q1909: Andrija Mehorovicic, a Croatian seismologist, used seismic waves to 

discover a discontinuity at a depth of about 50 km beneath the surface. This 

marks the boundary between what we now call the Earth’s crust and the 

underlying mantle. In his honor, we call the boundary separating the crust from 

the mantle the Mohorovicic discontinuity, or the Moho for short. 

Q1914: Beno Gutenberg used an extensive data set of earthquake wave travel 

times to compute the average distance to the top of the core at about 2,900 km. 

Q1926: Harold Jeffreys’ measurements of tides in the solid Earth suggested that 

the Earth was less rigid than had been previously assumed. This led to the 

assumption that the core is fluid. 

Q1936: Inge Lehmann, Danish seismologist, demonstrated the presence of an 

inner core. 

AGU / FEMA 160 S EISMIC S LEUTHS
AGU / FEMA 161 S EISMIC S LEUTHS
3.3 

VOCABULARY

Epicenter: the point on 

Earth’s surface directly 

above the focus of an 

earthquake. 

ACTIVITY ONE 

THE MERCALLI SCALE: CALLING STATION KWAT 

RATIONALE 

Students need to know how seismologists establish earthquake 

intensity in order to understand how much damage earthquakes can 

cause and how building codes are developed. 

FOCUS QUESTIONS 

How do seismologists determine the intensity of an earthquake? 

OBJECTIVES 

Students will: 

1. Interpret the Modified Mercalli scale and assign values on the basis 

of descriptions by citizen observers during and after a quake. 

2. Use the assigned values to construct an isoseismal map. 

MATERIALS

Q Overhead projector 

Q Student copies of Master 3.3a, Modified Mercalli Intensity Scale 

Q Transparency made from Master 3.3a, Modified Mercalli Intensity Scale 

Q Back of Master 3.3a, Teacher Background Reading: Richter vs. Mercalli 

Q Student copies of Master 3.3b, Wattsville Map 

Q Transparency made from Back of Master 3.3b, Wattsville Map Key 

Q One copy of Master 3.3c, KWAT Television Script, cut into strips 

Q Student copies of Master 3.3c, KWAT Television Script 

Q Colored pencils and lead pencils 

Focus (pl. foci): the point within the 

Earth that is the origin of an 

earthquake where stored energy is 

first released as wave energy. 

Intensity: a subjective measure of 

the amount of ground shaking an 

earthquake produces at a particular 

site, based on geologic effects, 

impact on human structures, and 

other human observations. Mercalli 

intensity is expressed in Roman 

numerals. 

Isoseismal line: a line on a map 

that encloses areas of equal 

earthquake intensity. 

Magnitude: a number that 

characterizes the size of an 

earthquake by measuring the 

motions on a seismograph and 

correcting for the distance to the 

epicenter of the earthquake. 

Magnitude is expressed in Arabic 

numbers.

AGU / FEMA 162 S EISMIC S LEUTHS
VOCABULARY 

Modified Mercalli scale 

of 1931: a qualitative 

scale of earthquake 

effects that assigns an 

PROCEDURE 

A. Introduction 

Ask students on what basis scientists classify earthquakes. Many 

students may be aware of the Richter Scale and some may be aware of 

the Mercalli Scale. Explain that the Richter Scale is a quantitative 

measure of the energy released by an earthquake, while the Mercalli 

Scale is a qualitative measure of the amount of damage it does. The 

Richter rating is referred to as a quake’s magnitude, and the Mercalli 

rating is referred to as its intensity. The original Mercalli Scale was 

developed in 1902 by the Italian geologist Giuseppi Mercalli. Wood 

and Neumann adapted it to U.S. conditions and introduced the 

Modified Mercalli Scale in 1931. Both the Richter and the Mercalli 

scales have their uses. Have students give other examples of 

quantitative vs. qualitative measurements. 

intensity number to the ground 

shaking for any specific location on 

the basis of observed effects. 

Mercalli intensity is expressed in 

Roman numerals. 

Qualitative: having to do with 

perceived qualities; subjective. 

Examples: large, cold. 

Quantitative: having to do with 

measurable quantities; objective. 

Examples: 10 m long, 5o C. 

B. Lesson Development 

1. Project the transparency of the Modified Mercalli Scale and 

distribute student copies. Share the background information about the 

two earthquake scales (back of Master 3.3a) with the class and discuss 

the importance of intensity in establishing building codes. Briefly 

discuss each of the values assigned on the Mercalli scale. If some 

students in the class have experienced an earthquake, ask them to 

estimate its intensity from the scale. 

2. Have the students compare and contrast the differences between the 

two types of measurements. Ask: Why do you think magnitude is 

more often reported than intensity? (Most earthquake-prone areas have 

equipment already in place to determine magnitudes, so this 

measurement can be quickly established. Mercalli ratings are 

sometimes not arrived at until several days later, when a full estimate 

of the damage can be made.) Point out to students that the lack of 

news accounts reporting intensity does not diminish its value to city 

planners and engineers. TEACHING CLUES AND CUES 

Have students listen 

carefully for significant 

phrases in the callers’ 

reports. They will be 

found in the Mercalli scale (Master 

3.3a).

It may take class discussion to reach agreement 

on the values for some 

of the reports. Have 

3. Tell students that in this activity they will be using data adapted 

from reports of an earthquake that struck California in 1971. 

Distribute copies of Master 3.3b, Wattsville Map. Appoint one student 

to be Jake Wilde, the television news anchor, and tell the other 

students that they are citizens of Wattsville and the surrounding area. 

The town has just been struck by an earthquake. 

4. Distribute the strips cut from Master 3.3c and have students take 

turns reading them in order, starting with the news anchor’s report. 

Distribute student copies of the script as well. 

5. As each student reads a part, have the other students locate the site 

of the report on their maps, scan the Modified Mercalli Intensity 

Scale, and mark a Mercalli intensity in pencil next to the location. 

6. After the last student has read, have students draw blue lines 

enclosing areas with equal intensity ratings to develop an isoseismal 

map. (They will be drawing a series of concentric lines.) 

students read the descriptions on the 

Mercalli scale carefully, and reread 

them as necessary, checking with 

the script as they proceed.

AGU / FEMA 163 S EISMIC S LEUTHS
7. Project the transparency of Master 3.3b, Wattsville Map, and have 

students take turns giving you the values to draw on the transparency. 

Then draw in the isoseismals according to their interpretation of the 

data. 

C. Conclusion 

Ask students to find the area where the damage was most intense and 

color this area red. Then build a class discussion around these 

questions: 

Q Where do you think the epicenter of the earthquake is located? 

(Most students will think that the area with the most damage is the 

epicenter. In certain cases this is a false assumption. Damage may 

be related to siting or construction practices. An example of this is 

the 1985 Mexico City earthquake in which the fault was over 350 

km away.) 

Q Why did some buildings near the epicenter withstand the shocks 

better than others? (perhaps because their structures were sounder 

or the soil under them was more firm) 

Q What are some advantages of the Mercalli rating procedure? (In 

ideal conditions, it can be done quickly, and it doesn’t require any 

instruments. It describes the impact in human terms: on human 

beings and their structures.) 

Q What are some disadvantages to this procedure? (It requires human 

observers, so it could not assign an intensity to an earthquake in the 

middle of an ocean or in a deserted place. It also requires the 

exchange of information over a fairly wide area. To arrive at 

Mercalli ratings today, an official survey is conducted through the 

U.S. mail. It is not as precise or objective as instrument readings; 

different people might describe the same situation differently.) 

Now place the answer key transparency on the overhead so it overlays 

student data. If there is a discrepancy between the isoseismals shown 

on the master and those students produced, they will see one of the 

drawbacks to this system of measurement. Ask students for 

suggestions to solve this problem. 

ADAPTATIONS AND EXTENSIONS 

1. Write a modern-day version of the 1931 Mercalli Intensity Scale. 

2. Go to the library and search newspapers for qualitative information 

on an earthquake in your area. Construct an isoseismal map for the 

earthquake. 

AGU / FEMA 164 S EISMIC S LEUTHS
VOCABULARY 

Amplitude: a measurement of the energy of a 

wave. Amplitude is the 

displacement 

ACTIVITY TWO 

RICHTER MAGNITUDE

RATIONALE 

To determine Richter magnitude, we need to know both the maximum wave amplitude as recorded on the seismogram and the distance 

between the seismograph station and the earthquake, which can be 

calculated by finding the lag time. 

FOCUS QUESTIONS 

How do scientists determine the size of an earthquake? 

OBJECTIVES 

Students will: 

1. Interpret seismograms to calculate Richter magnitude. 

2. Compare Richter magnitudes from several seismograph stations for 

the same earthquake. 

MATERIALS 

Q Transparency made from the first page of Master 3.3d, Five 

Seismograms 

Q Overhead projector 

Q Transparency marker 

Q Copies of Master 3.3d, Five Seismograms (simplified) (3 pages), 

one set for every two students 

Q Copies of Master 3.3e, Distance, Magnitude, Amplitude, one for 

every two students 

Q Paper and pencils or pens 

Q Rulers or straightedges 

Q Transparency made from Master 3.3e, Distance, Magnitude, 

Amplitude 

of the medium from zero or the 

height of a wave crest or trough from 

a zero point. 

Duration: the length of time that 

ground motion at a given site shows 

certain characteristics. Most earthquakes have a duration of less than 

one minute in terms of human 

perceptions, but waves from a large 

earthquake can travel around the 

world for hours. 

Lag time: the difference between 

the arrival time of P waves (Tp) and 

S waves (Ts). 

Magnitude: a number that characterizes the size of an earthquake by 

recording ground shaking on a 

seismograph and correcting for the 

distance to the epicenter of the 

earthquake. Magnitude is expressed 

in Arabic numbers. 

Richter magnitude: the number that 

expresses the amount of energy 

released during an earthquake, as 

measured on a seismograph or a 

network of seismographs, using the 

scale developed by Charles Richter 

in 1935. 

Seismogram: the record of earthquake ground motion recorded by a 

seismograph. 

Q Transparency made from back of Master 3.3d (page 2), Richter 

Data Table, Answer Key 

PROCEDURE 

A. Introduction 

Tell students that Richter magnitude is a quantitative measure that is 

related to the amount of energy released during the earthquake and is 

not attracted by factors such as population, building materials, or 

building design. Ask them to name some other kinds of quantitative 

measures (minutes, hours, centimeters, dollars). Be sure they understand the distinction between quantitative and qualitative description. 

B. Lesson Development 

1. Divide students into pairs. Give each pair a ruler and copies of 

Master 3.3d, Five Seismograms, and Master 3.3e, Distance, 

AGU / FEMA 165 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

The seismograms on 

Master 3.3d are 

seismograms that have 

been simplified and 

enlarged for classroom use. The 

printed millimeter scale has also 

been enlarged proportionately. 

Do not use rulers for this 

step or the 

measurement will be 

inaccurate. (Be sure 

they make all their 

measurements on the same wave 

cycle, not the crest from one and the 

trough from another. The diagram on 

p.116 will be helpful.) 

To measure the amplitude, have students lay 

a piece of paper across 

the wave and mark the 

Magnitude, Amplitude. Tell students that they are going to be working 

with five seismograms, all recorded for one earthquake on September 

2, 1992, with its epicenter at St. George, Utah. Explain that the 

seismographs have been enlarged and simplified for their use but that 

this has also changed the scale, so they must use the vertical scale for 

all measurements. You will be demonstrating the steps to determine 

magnitude by using the first seismogram on Master 3.3d. They will 

record their data on the bottom of the third page of seismograms. 

2. Project a transparency of Master 3.3d, page 1, and demonstrate how 

to measure amplitude. (See vocabulary definition.) Using the scale on 

the left side of the graph (the y axis) determine the greatest deflection 

in millimeters above or below zero of the largest seismic wave. Record 

this measurement in the amplitude column on the data table. 

3. After all students have measured amplitude, start the next part of the 

activity by asking them which earthquake wave travels fastest and 

therefore should be the first wave recorded on the seismogram. Most 

of them should be aware from previous lessons that it is the P wave. 

On the transparency of Master 3.3d, page 1, point out the arrival of the 

P and S waves. Ask students what the difference between the arrival of

the two waves is called (lag time (Ts-Tp). Ask students what should 

happen to the lag time recorded at stations farther from the earthquake. 

Offer a hint by comparing the progress of the waves to a race between 

the family car and a race car. The longer the race is, the more of an 

advantage the race car will have. 

4. Using the projection of Master 3.3d, page 1, demonstrate how to 

determine distance to the earthquake recorded by the first seismogram. 

Using the scale at the top of the graph (the x axis), measure the 

difference between P wave and S wave arrival times in seconds. Use 

the formula 

Distance = (Ts-Tp) x (8 km/sec) or (4.96 mi/sec) 

to convert time to distance. Have students record this in their data 

tables. Give students time to calculate the distances for the other four 

seismograms, following the procedure you have modeled. 

5. Project the transparency of Master 3.3e and demonstrate how to 

find the magnitude of the earthquake. To do this, place the left end of 

the ruler on the left scale at the distance calculated in step 4. Holding 

the left edge of the ruler in place, move the right edge of the ruler to 

the correct point for the base-to-peak amplitude. Read the Richter 

magnitude on the center scale where the ruler crosses the graph and 

record it in the data table. Have students repeat this process on their 

own for the other stations. Average the magnitudes from the five 

locations to determine the final magnitude for this earthquake, and 

record it in the data table. 

high and low peaks, then use the 

scale on the y axis or the scale 

printed at the bottom of the seismogram to measure the amplitude or 

distance. 

AGU / FEMA 166 S EISMIC S LEUTHS
C. Conclusion 

Project the back of Master 3.3d, Richter Data Table, Answer Key, and 

allow students to compare their calculations with the actual data. Ask 

students how a more accurate magnitude could be calculated. (by 

collecting more data points or by averaging the class averages of the 

calculated magnitude) 

ADAPTATIONS AND EXTENSIONS 

Seismologists today use a variety of magnitude scales and many types 

of instruments to record precise information on earthquakes. Interested 

students can read about P wave or body wave magnitude (called Mb), 

surface wave magnitude (Ms), moment magnitude (Mw), as well as the 

concept of seismic moment, drawing on materials in the unit resources 

list and others from local libraries. 

AGU / FEMA 167 S EISMIC S LEUTHS
VOCABULARY 

Epicenter: the point on 

Earth’s surface directly 

above the focus of an 

earthquake. 

ACTIVITY THREE 

FIND THE EPICENTER: DECODING SEISMOGRAMS

RATIONALE 

Students can find the location of an earthquake by triangulation if they 

know the distances from at least three seismograph stations. 

FOCUS QUESTION 

How do seismologists use seismograms to locate the epicenter of an 

earthquake? 

OBJECTIVES 

Students will: 

1. Calculate the distance from an earthquake to a seismograph station. 

2. Use five calculated distances to triangulate the location of the 

earthquake’s epicenter. 

MATERIALS 

QStudent copies of Master 3.3f, Several Seismographs 

QStudent copies of Master 3.3g, Sample Seismograms 

QStudent copies of Master 3.3h, Map of Station locations 

QTransparency made from one page of Master 3.3g, Sample 

Seismograms 

Focus (pl. foci): the point within the 

Earth that is the origin of an 

earthquake, where stored energy is 

first released as wave energy. 

Seismogram: the record of 

earthquake ground motion recorded 

by a seismograph. 

Seismograph: an instrument that 

records vibrations of the Earth, 

especially earthquakes. 

Triangulation: using data from three 

or more known points to locate an 

unknown point, in this case the 

epicenter of an earthquake.

QOverhead projector 

QTransparency made from Master 3.3h, Map of Station Locations 

QStudent copies of Master 3.3i, Time/Distance Reference Table 

QDrawing compasses 

QMetric rulers with millimeter scales 

PROCEDURE 

Teacher Preparation 

Make one copy of each of the masters (3.3f through 3.3i) for every 

two students in your class. 

A. Introduction 

Ask students chosen at random to explain the difference between an 

earthquake’s focus and its epicenter and between a seismograph and a 

seismogram. Review these distinctions if necessary. 

Distribute copies of Master 3.3f, Several Seismographs, then project a 

transparency of Master 3.3f and describe their operation. 

B. Lesson Development 

1. Divide the class into pairs of students. Distribute a set of 

seismograms (Master 3.3g, 3 pages), one map (Master 3.3h), and 

copies of the Time/Distance Reference Table (Master 3.3i) to each 

AGU / FEMA 168 S EISMIC S LEUTHS
pair. Tell students that all the seismograms are from the same 

earthquake, a quake that occurred on January 14, 1993, with a 

magnitude of 3.3, but each was recorded by a different seismograph in 

the seismograph network. 

2. Project transparencies of one seismogram and the map. Model the 

procedure for students as necessary. 

3. Give these directions for finding the epicenter of the earthquake 

recorded on the five seismograms: 

a. On the first seismogram, use the second scale to measure the timedistance from the nearest 10-second mark to the P wave arrival of the 

earthquake. Record the P wave arrival times in the table to the nearest 

second. 

b. Repeat for the S wave, measuring from the same minute mark. 

c. Find the Ts-Tp time by subtracting the arrival time of the P wave 

from the arrival time of the S wave. Record this time in the table. 

d. Use the time/distance table on Master 3.3i to determine the distance 

to the epicenter. 

e. Repeat this procedure for all of the stations. 

f. For each seismogram, draw a circle on the map with the compass, 

using the distance you calculated as the radius of the circle. Place the 

point of the compass at zero on the map scale and adjust the compass 

width to the calculated distance. With the distance set, place the point 

of the compass on the station and draw a circle. Mark the outer edge of

each circle with a letter to identify the station. TEACHING CLUES AND CUES 

Emphasize the importance of accurate measurement, particularly 

the need to set the 

g. Repeat, setting the compass and drawing circles for 0 five stations. 

4. Instruct students to circle the area where all the circles intersect. 

Ask: What is this area called? (It is the epicenter of the earthquake.) 

C. Conclusion 

Build a class discussion around these questions: 

Q What information can be obtained from one seismogram? (The 

distance from that seismograph in a 360o circle.) 

Q After the arcs for stations TRYN and FGTN were drawn, where 

was the epicenter of this earthquake? Explain. (We don’t know yet. 

It could be at either place where the two arcs cross. They are the 

common points.) 

Q After all the stations were drawn, where was the actual epicenter of 

this earthquake? Where was its focus? (In the area where the arcs 

cross just south of station BHT. Directly under the epicenter.) 

Q Why is it necessary to have measurements from at least three 

different stations to locate the epicenter of an earthquake? (Answers 

will vary but should relate to the above questions.) 

Q Why don’t all of the arcs pass through the same point? (Answers 

will vary. Accuracy in measurement and drawing should be two 

compass accurately for distance. 

Don’t worry if the circles don’t 

intersect perfectly, however. Remind 

students that an earthquake actually 

occurs along a fault, not at one 

single point.

AGU / FEMA 169 S EISMIC S LEUTHS
most common. Also, an earthquake does not occur at one point but 

along a fault surface. Have students speculate as to the location and 

strike of the fault. 

Q Which station was closer to the earthquake’s epicenter, BBG or 

FGTN? Cite two kinds of evidence from the seismograms to 

support your conclusion. (BBG. Evidence: amount of lag time and 

amplitude difference.) 

Q Would it be possible for an earthquake at this location to be felt 

where you live? Why or why not? (Answers will vary; will depend 

on distance from the focus and the magnitude of the quake.) 

Q P waves travel at an average velocity of 6 km/sec in the Earth’s 

crust. How long would it would take for the P waves from this 

quake to reach a seismic station in your city, if they continued to 

travel at a constant speed? (Answers will vary. Multiply 6 km/sec 

times the distance to your city.) 

ADAPTATIONS AND EXTENSIONS 

1. Challenge students to research these questions: 

Q Would a seismograph work on the moon? 

Q Have scientists placed seismographs on the moon and other planets? 

Q If so, which planets? Have quakes been detected there? 

2. Interested students may research several types of seismographs and 

build their own models. V

AGU / FEMA 170 S EISMIC S LEUTHS
AGU / FEMA 171 S EISMIC S LEUTHS
3.3a MASTER PAGE Modified Mercalli Intensity Scale

Intensity Value & Description 

I. Not felt except by a very few under especially favorable circumstances. II. Felt only by a few persons at rest, especially on upper floors of buildings. Delicately suspended objects may swing. III. Felt quite noticeably indoors, especially on upper floors of buildings, but many people do not recognize it as 

an earthquake. Standing automobiles may rock slightly. Vibration like passing of truck. Duration estimated. IV. During the day felt indoors by many, outdoors by few. At night some awakened. Dishes, windows, doors 

disturbed; walls make creaking sound. Sensation like heavy truck striking building. Standing automobiles rocked noticeably.V. Felt by nearly everyone, many awakened. Some dishes, windows, and so on broken; cracked plaster in a few places; unstable objects overturned. Disturbances of trees, poles, and other tall objects sometimes noticed. Pendulum clocks may stop. VI. Felt by all, many frightened and run outdoors. Some heavy furniture moved; a few instances of fallen plaster 

and damaged chimneys. Damage slight.VII. Everybody runs outdoors. Damage negligible in buildings of good design and construction; slight to 

moderate damage in well-built ordinary structures; considerable in poorly built or badly designed structures; some chimneys broken. Noticed by persons driving cars. VIII. Damage slight in specially designed structures; considerable in ordinary substantial buildings, with partial 

collapse; great in poorly built structures. Panel walls thrown out of frame structure. Chimneys, factory stacks, columns, monuments, walls may fall. Heavy furniture overturned. Sand and mud ejected in small amounts. Changes in well water. Persons driving cars disturbed. IX. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb; great in substantial buildings, with partial collapse. Buildings shifted off foundations. Ground cracked conspicuously. Underground pipes broken. X. Some well-built wooden structures destroyed; most masonry and frame structures destroyed with 

foundations; ground badly cracked. Rails bent. Landslides considerable from river banks and steep slopes. Shifted sand and mud. Water splashed, slopped over banks. XI. Few, if any (masonry) structures remain standing. Bridges destroyed. Broad fissures in ground. 

Underground pipelines completely out of service. Earth slumps and land slips in soft ground. Rails bent greatly. XII. Damage total. Waves seen on ground surface. Lines of sight and level distorted. Objects thrown into the 

air. 

AGU / FEMA 171 S EISMIC S LEUTHS
MASTER PAGE Teacher Background Reading 

Richter vs. Mercalli

3.3a 

When an earthquake occurs, we often hear news 

reporters describing it in terms of magnitude. Perhaps 

the most common question at a news conference is 

“What was the magnitude of the quake?” In addition 

to calculating the magnitude of an earthquake, 

however, we can describe the effect it had at a 

particular location by measuring its intensity. 

Magnitude and intensity are both measures of an 

earthquake, but they describe different characteristics. 

Each measurement has its uses. 

Magnitude is a measurement of the amplitude of the 

earthquake waves, which is related to the amount of 

energy the earthquake releases. Magnitude is 

calculated from the size of the earthquake waves 

arriving at a seismic station. The most commonly used 

scale for magnitude is the Richter scale, developed by 

Charles Richter in 1935. The Richter scale is a 

logarithmic measurement of the maximum wave 

amplitude recorded at a seismograph station, corrected 

for distance from the epicenter. It is theoretically 

open-ended, although the largest quakes recorded in 

this century had a magnitude of 8.9. Each whole 

number increase in Richter magnitude indicates an 

increase in the severity of the ground shaking by a 

factor of 10. Thus a magnitude 6 earthquake will produce shaking 10 times more severe than that produced 

by a magnitude 5 earthquake. Magnitude can also be 

related to the amount of energy an earthquake releases. 

Each whole number increase in Richter magnitude 

indicates an increase in the amount of energy released 

by a factor of roughly 30. Thus a magnitude 6 

earthquake releases about 30 times more energy than a 

magnitude 5 earthquake, and roughly 900 times as 

much as a magnitude 4 earthquake. These factors are 

seldom described correctly in news accounts. 

Each earthquake has a single magnitude that is independent of the location of the observer. If a magnitude 

6.0 event strikes some location in the South Pacific, 

then that event will be described as a magnitude 6.0 

by observers all over the world. Because magnitude is 

independent of observer location, it is a convenient 

measure to use in reporting the occurrence of an 

earthquake. No matter where it happened, or where 

you are, you get a feeling for the relative size of the 

earthquake by simply knowing its magnitude. This is 

why the press is so quick to report this number. 

Intensity is a measure of the effect that the vibration 

had on natural and human-made structures. The most 

common measurement of intensity is the Modified 

Mercalli Intensity scale, originally developed in 1902 

by Giuseppi Mercalli, an Italian geologist. Wood and 

Neumann adapted it to “modern” conditions in 1931. 

The intensity scale ranges from I, the lowest 

perceptible intensity, to XII, the greatest intensity. 

Intensity is a function of many variables, including 

magnitude, depth of the earthquake, distance from the 

earthquake, local geological conditions, and local 

construction practices. Generally speaking, the 

intensity felt at a given location will increase with 

increasing magnitude, decreasing depth, decreasing 

distance from the earthquake, and a decrease in the 

quality of construction. If an earthquake is shallow, its 

intensity will be greater. If it affects an area built on 

soft sediments, such as landfills or sedimentary basins, 

the intensity will also be greater. A single quake will 

produce a range of intensities that typically decrease 

with increasing distance from the earthquake. An 

isoseismal map illustrates this range. 

Intensity is more useful than magnitude as a measure 

of the impact that an earthquake had at any given 

location. Consequently, it is important to the 

professionals who establish building codes and 

insurance rates. If the maximum expected intensity in 

a given area is VII, for example, the building codes 

should specify construction practices that make 

buildings able to withstand this intensity, and property 

insurance rates will probably be high. If the maximum 

expected intensity is only III, the area can relax its 

building codes, and property insurance rates will be 

moderate. 

AGU / FEMA 172 S EISMIC S LEUTHS
3.3b MASTER PAGE Wattsville Map

Name ___________________________________________________________ Date _____________________ 

AGU / FEMA 173 S EISMIC S LEUTHS
3.3b MASTER PAGE Wattsville Map (key)

Note: Isoseismal lines and locations may vary. 

AGU / FEMA 174 S EISMIC S LEUTHS
MASTER PAGE KWAT Television Script 3.3c 

Jake Wilde: “We interrupt our regularly scheduled programming on KWAT to bring you a special bulletin. This 

is KWAT news anchor Jake Wilde, and moments ago the town of Wattsville was shaken by a strong earthquake. 

Residents in the KWAT broadcast area are invited to call our emergency response number, 324- KWAT, and give 

us your name, your location, and a brief summary of what you experienced during the quake. Stay tuned for the 

latest reports of what your neighbors saw and felt. To report your observations, again, call 324-KWAT. We have 

caller number 1 on the line.” 

Caller 1: “Hi, this is Charles from the hospital. Everyone ran outdoors and we only had moderate damage thanks 

to a well-built building.” 

Caller 2: “Hello my name is Roy, and I’m calling from RQB Ranch. Everything that wasn’t nailed down in our 

tack room got turned upside down by the shaking. Some plaster is cracked too.” 

Caller 3: “Hi, this is Bob at Long Valley Mercantile, and we have a mess here. When the quake struck, it knocked 

over all of our displays, and broke windows out of the store. All the trees and poles were moving.” 

Caller 4: “Hi Jake, I’m Jane calling in from West Side Subdivision. Damage was slight here—only some plaster 

shaken off the walls and the heavy furniture moved around.” 

Caller 5: “Hi. This is Jo. I’m calling from the north end of town and we need some help down here. The water in 

our well has changed its level and we are trying to put out fires with buckets.” 

Caller 6: “Hello Jake, Lynda from Southside City Junior High School. Students felt it and did the drop, cover, 

and hold drill. We only had slight damage to the building, with some fallen plaster.” 

Caller 7: “Hi, this is Hank and I’m calling on my car phone. I just heard the news and thought I would report that 

right after I turned south into town off the Interstate, I felt a big bump—but there were not any potholes in the 

road. It was disturbing.” 

Caller 8: “Hello, this is Mary, and I’m calling from the basement of the First Bank in the center of Wattsville. 

The building has partially collapsed and people are trapped down here. Please send help.” 

Caller 9: “Hi this is Jim. We were at the mall when the quake struck. Everyone panicked and ran outside. Luckily 

no one was hurt, and damage was slight.” 

AGU / FEMA 175 S EISMIC S LEUTHS
MASTER PAGE 

Caller 10: “Hi, this is Ron. I work at the MacBest Castle. Many of the tourists were frightened and ran outdoors, 

and our chimneys were damaged.” 

Caller 11: “Hello Jake. My name is Sue and I’m calling from the Big Bear Lumber Camp. The walls of our house 

were swaying and creaking during the earthquake.” 

Caller 12: “Hi. This is Len. We were picnicking at the Great Bend Park. Shortly after the quake struck we saw 

trees, telephone poles, and the flagpole swaying back and forth.” 

Caller 13: “Hi. This is Jim out at the Roundup Truck Stop. When the quake hit, our chimney broke and fell over.” 

Caller 14: “Hello, Jake. This is Marty up at Big Bear Ski Resort. The quake rattled our dishes and windows, and 

the walls made creaking sounds.” 

Caller 15: “Hi Jake. This is Keith in River City. Our chimney is damaged and some plaster has fallen.” 

Caller 16: “Hi. This is Diana calling from the Lucky Strike Mine. Over here, we thought that a big truck had 

struck the building.” 

Caller 17: “Hi Jake. This is Monte from Wattsville University. Everyone in our class felt the quake, and some of 

the older, more poorly built buildings have suffered considerable damage.” 

Caller 18: “Hello. My name is Marilyn, and I’m calling from Hot Springs Ranch. The strangest thing happened! 

Our big pendulum clock stopped dead when the quake struck.” 

Caller 19: “Hi Jake, this is Karen. When the quake hit, I was in White Water visiting a friend. Nearly everyone 

felt it and we had a lot of windows broken. They were frightened, and I was too!” 

Caller 20: “Hello Jake. This is Frank. I was at Blue Lake Resort when all the cars in the parking lot started 

rocking back and forth.” 

Caller 21: “Jake, this is Gene at White Water Manufacturing. All of the heavy furniture in the showroom was 

moved by the quake, and some of the plaster fell off the walls.” 

AGU / FEMA 176 S EISMIC S LEUTHS
MASTER PAGE Five Seismograms 

Simplified 

3.3d 

Name ___________________________________________________________ Date _____________________ 

AGU / FEMA 177 S EISMIC S LEUTHS
MASTER PAGE 

AGU / FEMA 178 S EISMIC S LEUTHS
MASTER PAGE 

Richter Magnitude Data Table 

Location Amplitude Ts – Tp Distance Magnitude 

Salt Lake City, UT mm sec km 

Pinyon Flats, CA mm sec km 

Tucson, AZ mm sec km 

Pasadena, CA mm sec km 

Yuma, AZ mm sec km 

Final magnitude 

(average of 5) 

AGU / FEMA 179 S EISMIC S LEUTHS
3.3d MASTER PAGE Five Seismograms (key) 

Richter Data Table, Answer Key 

LOCATION AMPLITUDE Ts – Tp DISTANCE MAGNITUDE 

Salt Lake City, UT 14.0 mm 56 sec 448 km 5.6 

Pinyon Flats, CA 10.0 mm 59 sec 472 km 5.7 

Tucson, AZ 6.0 mm 75 sec 600 km 5.8 

Pasadena, CA 7.0 mm 68 sec 544 km 5.7 

Yuma, AZ 13.0 mm 62 sec 496 km 5.8 

Note: Answers will vary. 

Final magnitude 5.7 

St. George, Utah, Earthquake Data

September 2, 1992 10:26 UTC 

Location: 37 o 5.4' N latitude, 113 o 28.3' W longitude 

Final Magnitude: 5.8 

(Determined by University of Utah based on readings from 18 stations.) 

AGU / FEMA 180 S EISMIC S LEUTHS
3.3e MASTER PAGE Distance, Magnitude, Amplitude 

AGU / FEMA 181 S EISMIC S LEUTHS
AGU / FEMA 182 S EISMIC S LEUTHS
MASTER PAGE Several Seismographs 3.3f 

Chinese seismoscope, 132 A.D. The direction 

in which the first ball fell was thought to 

indicate the direction of the epicenter. 

Inside view Modern seismographs 

A simple pendulum seismograph 

AGU / FEMA 183 S EISMIC S LEUTHS
AGU / FEMA 184 S EISMIC S LEUTHS
MASTER PAGE Sample Seismograms 3.3g 

Name ___________________________________________________________ Date _____________________ 

AGU / FEMA 185 S EISMIC S LEUTHS
MASTER PAGE 

AGU / FEMA 186 S EISMIC S LEUTHS
MASTER PAGE 

Note: Seismogram source: Center for Earthquake Research and Information, Memphis State University. 

STATION Tp Ts Ts – Tp DISTANCE 

TRYN 2 sec 32 sec 30 sec 240 km 

TKL 

FGTN 

BBG 

BHT 

AGU / FEMA 187 S EISMIC S LEUTHS
MASTER PAGE Sample Seismograms (key) 3.3g 

STATION S-P DISTANCE 

(kilometers) 

RADIUS OF ARC IN MM 

(assuming 1mm=3km) 

TRYN 30 240 80 

TKL 15 120 40 

FGTN 27 216 72 

BBG 12 96 32 

BHT 11 88 29 

Note: Answers will vary.

AGU / FEMA 188 S EISMIC S LEUTHS
MASTER PAGE Map of Station Locations 3.3h 

Name ___________________________________________________________ Date _____________________ 

AGU / FEMA 189 S EISMIC S LEUTHS
MASTER PAGE Map of Station Locations (key) 3.3h 

AGU / FEMA 190 S EISMIC S LEUTHS
MASTER PAGE Time/Distance Reference Table 3.3i 

The slope of this line is based on the equation 

(Ts – Tp) x 8 = D 

Examples

(60 - 50) x 8 = 80 

(60 - 40) x 8 = 160 

(60 - 30) x 8 = 240 

(60 - 20) x 8 = 320 

(60 - 10) x 8 = 400 

AGU / FEMA 191 S EISMIC S LEUTHS
AGU / FEMA 192 S EISMIC S LEUTHS
3.4 

Distribution of

VOCABULARY

Epicenter: the point on 

Earth’s surface directly 

above the location 

(focus) of the 

earthquake below the 

surface. 

ACTIVITY ONE 

WHERE IN THE WORLD? 

RATIONALE 

Knowing where earthquakes occur will allow students to formulate 

theories about what causes earthquakes and why earthquakes occur 

more commonly in particular locations. 

FOCUS QUESTIONS 

Where have earthquakes been known to occur? 

Do earthquakes occur randomly, or mainly in specific areas? 

OBJECTIVES 

Students will: 

1. Locate and plot the epicenters of earthquakes by latitude and 

longitude. 

2. Recognize a pattern in the distribution of most earthquakes. 

3. Postulate how the occurrence of earthquakes may be related to plate 

tectonic activity. 

4. Postulate how deep earthquakes may be related to plate tectonic 

activity. 

Focus (pl. foci): the point within the 

Earth that is the origin of an 

earthquake, where stored energy is 

first released as wave energy. 

Latitude: the location of a point 

north or south of the equator, 

expressed in degrees and minutes. 

Latitude is shown on a map or globe 

as east-west lines parallel to the 

equator. 

Longitude: the location of a point 

east or west of the prime meridian, 

expressed in degrees and minutes. 

Longitude is shown on a map or 

globe as north-south lines left and 

right of the prime meridian, which 

passes through Greenwich, England.

MATERIALS 

Q Student copies of Master 3.4a, Earthquakes of the Day, Tables 1-8 

(one set of eight, plus extras as needed) TEACHING CLUES AND CUES 

Q One copy of Master 3.4b, Notable World Earthquakes, 1900-1992 

Q Eight copies of Master 3.4c, World Map (2 pages) 

Q Scissors and transparent tape 

Q Atlases, globes, or geography textbooks with detailed maps 

Q Pencils or pens, both black and red 

Q Four transparencies made from each page of Master 3.4c, World 

Map 

Do not reduce the map 

to one page. The scale 

will be too small to be of 

use.

AGU / FEMA 193 S EISMIC S LEUTHS
Q Three black transparency markers and three red ones TEACHING CLUES AND CUES 

Q Overhead projector 

Q Student copies of Master 2.2e, World Map Grid (key) 

If your class is very 

large, you may want to 

give each group more 

than one copy of the 

PROCEDURE 

Teacher Preparation 

Borrow a number of globes and/or atlases in addition to the ones you 

keep in the classroom, so students can locate cities and countries as 

they plot latitude and longitude. 

A. Introduction 

Briefly review the system of latitude and longitude and how these 

coordinates are used to pinpoint geographic locations. Ask the 

students what country or region of the world they think has the largest 

number of earthquakes in any given year. Note their answers on the 

chalkboard or on poster paper, but do not comment. Tell them that in 

this activity they will be working with real earthquake data. 

B. Lesson Development 

1. Divide students into eight roughly equal groups. Distribute one of 

the eight tables in Master 3.4a, Earthquakes of the Day, to each group. 

Explain that each of the tables lists the earthquakes that occurred 

around the world on one day; all were recorded on the monthly listing 

from the U.S. Department of the Interior/U.S. Geological Survey, 

Preliminary Determinations of Epicenters. Give Master 3.4b, Notable 

World Earthquakes, to the group with Table I (1/1/90), along with one 

blank transparency. 

tables and the map so students can 

work in smaller subgroups.

TEACHING CLUES AND CUES

Do not reduce the map 

to one page. The scale 

will be too small to be of 

use. 

2. Give each group a copy of Master 3.4c, World Map. Have students 

cut and tape the two pages together. Do not reduce to one page. 

Students in each group may take turns finding the epicenters and 

marking the maps. 

3. Instruct students to distinguish the locations of earthquakes below 

40 km from the more common shallow earthquakes by drawing rings 

around the dots that represent them with the red pencil or pen. 

4. Distribute the other three transparency maps and markers to the 

three groups that complete their work first. Instruct students in each 

group to transfer the positions on their maps onto the transparency, 

using the black and red markers as above, and write the dates of the 

earthquakes depicted on the map. As each group completes its work it 

may pass the transparency on to another group until all the 

earthquakes from all nine tables have been recorded on the three 

transparencies. 

5. Instruct the group working with Master 3.4b to plot those 

earthquakes on their separate transparency and label it. 

6. Collect the transparency maps. Stack the three depicting 

earthquakes of the day (Tables 1-8) on the projector so that they are 

displayed simultaneously. Then distribute copies of Master 2.2e, the 

key to the World Map Grid from lesson 2.2.

AGU / FEMA 194 S EISMIC S LEUTHS
7. Ask students to compare the world map you have just distributed 

with the stacked transparencies. Ask: 

Q Can you detect any relationship between the locations of 

earthquakes below 40 km and the outlines of Earth’s plates? (These 

earthquakes occur under the continents on the landward side of 

plate boundaries.) 

Q Do all the earthquakes occur at or near plate boundaries? (Some 

earthquakes occur in places that seem unrelated to plate 

boundaries.) 

Q Were any of the students correct in judging where earthquakes 

occur most frequently, at the beginning of class? 

8. Ask students to note how earthquakes are distributed among the 

four geographic areas: north latitude/west longitude, north latitude/east 

longitude, south latitude/west longitude, and south latitude/east 

longitude. Ask them to speculate on the reasons for this distribution. 

(The northeast quadrant has the highest concentration of quakes. The 

main portion of the Ring of Fire is in this quadrant.) 

TEACHING CLUES AND CUES 

Don’t tell students how 

to calculate the total; 

challenge them to find a 

way. One procedure 

9. Remind students that the eight tables represent earthquakes that 

occurred on just eight days. Ask them to count the total number of 

quakes and estimate how many earthquakes occur each year. (Students 

should calculate that more than 15,000 significant earthquakes occur 

each year.) 

10. Ask students where the world’s most powerful earthquakes have 

occurred. Record their hypotheses, then place the transparency of 

Master 3.4b on top of the others as a check. Ask students to predict 

where major earthquakes will occur in the future. 

C. Conclusion 

Sum up in a discussion. Ask the class: 

is for each group to report the 

numbers on its map (Tables 1 

through 8), then for students to add 

the numbers and average them. The 

average of 42 quakes a day, multiplied by 365, yields a figure of 

15,630. 

Q Are people who live near the boundaries of major tectonic plates the 

only ones who have to worry about earthquakes? Why or why not? 

(No. The majority of earthquakes occur along plate boundaries, but 

some quakes do occur within the plates.) Invite students to speculate 

about the causes of intraplate earthquakes and faulting. 

Q Does the amount of damage an earthquake does depend only on its 

magnitude? (No. Population density, soil conditions, building types, 

and other factors determine the amount of damage. Students will 

learn more about these factors in subsequent units.) 

ADAPTATIONS AND EXTENSIONS 

1. Obtain copies of Preliminary Determinations of Epicenters and have 

students plot other kinds of data on fresh copies of the map, such as: 

a. Earthquakes having magnitudes greater than magnitude 5 for (1) the 

world; (2) a particular region of the country, or (3) a particular state or 

local area. 

b. Earthquakes that have caused the greatest damage or loss of life. 

AGU / FEMA 195 S EISMIC S LEUTHS
VOCABULARY 

Epicenter: the point on 

Earth’s surface directly 

above the focus of an 

earthquake. 

ACTIVITY TWO 

THE PLOT THICKENS: PLOTTING EARTHQUAKE 

FOCI IN THREE DIMENSIONS

RATIONALE 

This activity graphically illustrates the patterns in the distribution of 

earthquake foci in one relatively small area. 

FOCUS QUESTION 

What would the pattern of earthquakes in one region look like if it 

could be observed in three dimensions over a period of time? 

OBJECTIVE 

Students will plot location and depth for one group of earthquakes and 

observe their relationships. 

MATERIALS 

for the teacher 

Q One copy of Master 3.4d, Central Japan (2 pages, left and right) 

Q Stiff cardboard, 30 cm x 60 cm (1 ft. x 2 ft.) 

Q Phillips screwdriver to punch holes for hanging 

Q Four pieces of cord or other support (See Teacher Preparation.) 

Q Glue or transparent tape 

Q Wall map of Japan or student atlases 

for each small group 

Q One copy of Master 3.4d, Central Japan (2 pages, left and right) 

Q One copy of Master 3.4e, Selected Earthquakes Since 1980, Japan 

Q Pencils, pens, and metric rulers 

Q Transparent tape 

Q Small craft beads such as 12 mm or 8 nun 

Q Dental floss or other strong, fine string 

Q Scissors 

Q One size 8-d nail 

PROCEDURE 

Teacher Preparation 

Use a copier to enlarge the two-part map until it can cover most of the 

cardboard. Glue or tape the map to the top side of the cardboard. 

Attach cord to the four corners and hang it from the ceiling, or rest it 

on supports above the floor at a height that will be about eye level for 

most students. Make standard-size copies of the two-part map for desk 

use. 

Focus (pl. foci): the point within the 

Earth that is the origin of an 

earthquake, where strain energy is 

first released as wave energy. 

Magnitude: a number that 

characterizes the size of an 

earthquake by recording ground 

shaking on a seismograph and 

correcting for the distance to the 

epicenter of the earthquake. 

Magnitude is expressed in Arabic 

numbers. 

AGU / FEMA 196 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

Deep-focus earthquakes 

produce seismograms 

very different from those 

produced by shallowA. Introduction 

Tell students that earthquakes occur in many locations and at different 

depths. The study of earthquakes has provided most of what we now 

know about the Earth’s structure. The patterns of their locations 

provided much of the evidence that led geologists to hypothesize the 

existence of plates. 

B. Lesson Development 

1. Divide the class into the same groups as for Activity One of this 

lesson. Give each group one copy of Master 3.4d, Central Japan (two 

pages, left and right) and Master 3.4e, Selected Earthquakes Since 

1980, Japan. Instruct students to cut the left page of Master 3.4d along 

the dotted line and tape it to the right page. 

2. Divide the list of earthquakes into as many equal sections as you 

have student groups, and assign one section to each group. It is not 

necessary to use all the earthquakes. (If you have eight groups, each 

will be responsible for 10 quakes.) Instruct students to begin plotting 

their assigned quakes from Master 3.4e on the map of Japan by 

latitude and longitude, then mark each epicenter with its reference 

number, depth, and magnitude. Point out that 10 small squares on their 

maps represent one degree of longitude and one degree of latitude. 

3. When the first group has located all the quakes on its own section of

the list, it can transfer those locations to the hanging map. Other 

groups can follow as they complete their sections. Give these 

instructions for transferring data to the hanging map: 

a. For each earthquake, take two beads of the same color. Use one 

bead to represent the epicenter of each quake and the other bead to 

represent its focus. 

b. Locate the latitude and longitude of the first quake on the hanging 

map. Mark its epicenter and punch a hole all the way through the 

cardboard with the nail. Thread dental floss through the small bead 

and tie a knot to hold the bead at the correct location. Calculate the 

distance below the map at which the large ball will be hung (the depth 

of the focus) by letting 1 cm stand for 5 km. The bead representing 

earthquake #1 will hang 2 cm below its epicenter. Tie knots to hold 

the beads in place. 

c. Repeat this procedure until all the quakes have been plotted on the 

map. When students have finished, invite them to view this 3-D plot 

from many directions. 

4. Ask: 

focus earthquakes. EPIC and some 

of the other non-print media sources 

listed in the resources for Units 2 

and 3 can provide examples of both 

for you to show your students. 

Q What pattern do you see? Where do the earthquakes concentrate? 

(on the lower right) 

Q What do you think is happening to the Earth’s crust in this area? 

(Old crust is being broken off and pushed under the edges of the 

plate, in the process geologists call subduction.) 

AGU / FEMA 197 S EISMIC S LEUTHS
C. Conclusion 

Call students’ attention to the atlas or wall map of Japan. Ask them if 

they view the map differently now that they can see what it represents 

in three dimensions. What kind of information would clarify their 

view further? 

ACTIVITY THREE 

WHERE IN NORTH AMERICA? 

RATIONALE 

By plotting earthquake epicenters on a map, students will learn where 

earthquakes occur on the North American continent and that they can 

occur almost anywhere. 

FOCUS QUESTIONS 

Where in North America do earthquakes occur? 

How often do earthquakes occur in specific locations on the North 

American continent? 

OBJECTIVES 

Students will: 

1. Interpret data tables and plot locations on a map. 

2. Discover that most areas are prone to earthquakes. 

MATERIALS 

Q Master 3.4f, North American Epicenters, 1990 

Q Classroom wall map of North America or transparency made from 

Master 3.4g, Map of North America 

Q Overhead projector 

Q Transparency markers in red, green, and blue 

Q Three transparencies made from Master 3.4g, Map of North 

America 

for each small group 

Q Student copies of Master 3.4g, Map of North America 

Q One strip of earthquake epicenters cut from Master 3.4f 

Q Pencils or pens 

PROCEDURE 

Teacher Preparation 

Make a copy of Master 3.4f. Cut it into as many horizontal sections as 

you have groups, dividing the list of epicenters so each group has 

approximately the same number of earthquakes to plot. 

AGU / FEMA 198 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

In the EPIC Data Base, 

times are given in 24-

hour Universal Time 

(UT) and carried out to 

A. Introduction 

From the other activities in this lesson, students have discovered 

where earthquakes occur worldwide and how seismologists locate 

them. Ask the class where earthquakes occur on the North American 

continent. Most of them will probably name California. Accept this, 

but try to elicit other locations as well. Some may be aware of the New 

Madrid, Missouri, earthquakes in the 19th century, or of other 

earthquakes close to home. 

Remind students that earthquakes sometimes occur where volcanoes 

are present. Ask: Where on the North American Continent are 

volcanoes found? Students will probably identify the western United 

States. Tell them that at one time volcanoes erupted in the eastern part 

of the continent. The famous Palisades, a line of steep cliffs along the 

Hudson River in New York and New Jersey, were caused by volcanic 

activity. Tell students that in this activity they will use selected data 

from the U.S. Geological Survey to plot the locations of earthquakes 

of magnitude 4 or larger that occurred during 1990 on the North 

American continent. 

B. Lesson Development 

1. Divide the class into groups of three or four students each. 

2. Distribute copies of Master 3.4g, the blank map, and the epicenter 

strips. Review latitude and longitude if necessary. 

3. Have students plot the locations of the epicenters on their maps. 

Give these directions: 

a. As you locate each point, mark it with a small dot. Then write the 

depth and magnitude of the earthquake next to it in small numbers. 

b. When you finish, transfer your data to one of the three 

transparencies of Master 3.4g, using the colored pens to code for 

magnitude. Green will represent magnitude 4, blue magnitude 5, and 

red magnitude 6 or greater. Mark each earthquake with an X in the 

appropriate color. 

4. When all the data have been plotted, stack the transparencies on the 

overhead so you can display them simultaneously. Ask students to 

comment on the pattern they observe, and compare it with their 

findings in Activity One. Do they see a similar pattern? They should 

see once again that earthquakes occur primarily near plate boundaries 

(for the U.S., on the west coast) but are not limited to those areas. Is 

there a pattern to the depth of the earthquakes? (The deepest quakes 

occur at plate margins under continents. This pattern may not be 

evident in this data.) 

C. Conclusion 

Remind students that these data are for one year only, and only for 

earthquakes of magnitude 4 or greater. Have them discuss what they 

would need to prepare an earthquake risk map for building codes or 

insurance rates. (The obvious answer will be more data, but point out 

to students some of the things they have already learned about 

eight places—210117.90, for 

example, which would be approximately 9:01 pm. In Master 3.4f they 

have been shortened to four places 

(2101). 

AGU / FEMA 199 S EISMIC S LEUTHS
earthquakes, such as how waves travel through the Earth, and tell them 

that in later lessons they will learn about engineering to improve 

structural resistance to earthquakes.) 

ADAPTATIONS AND EXTENSIONS 

1. Obtain a copy of the EPIC software (free demonstration files are 

available) or the EPIC CD-ROM, and have students research earthquakes of different magnitudes and different locations. See the unit 

resource list. 

2. Have students contact the National Earthquake Information Center 

(NEIC) and report back to class on data and services available. See the 

Unit 2 resource list. 

3. Have students contact the Incorporated Research Institutions for 

Seismology (IRIS) and report back to class on data and services 

available. See the Unit 2 resource list. 

4. The NEIC and IRIS maintain remote bulletin boards. Have students 

find out how to access them and research earthquakes. V

AGU / FEMA 200 S EISMIC S LEUTHS
3.4a MASTER PAGE Earthquakes of the Day

Table 1. Earthquakes That Occurred on January 1, 1990 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** Location 

North Latitudes and West Longitudes 

0:22 62 N 150 W 39 2.9 Southern Alaska 

1:10 16 N 63 W 33 3.6 Leeward Islands 

13:22 37 N 122 W 15 2.6 California 

18:03 7 N 73 W 158 5.3 Colombia 

22:59 33 N 115 W 4 3.2 California/Mexico 

23:17 38 N 119 W 11 3.1 California 

23:29 52 N 179 W 33 4.4 Aleutian Islands 

North Latitudes and East Longitudes 

2:47 36 N 27 E 145 3.3 Dodecanese Islands 

3:25 44 N 7 E 10 1.6 Northern Italy 

6:34 42 N 19 E 10 3.3 Albania 

9:03 36 N 141 E 68 4.8 East coast, Honshu Japan 

9:30 40 N 29 E 10 — Turkey 

16:20 43 N 13 E 10 — Italy 

16:38 47 N 10 E 5 3.1 Switzerland 

17:13 50 N 174 E 33 4.6 Aleutian Islands 

18:19 45 N 7 E 10 2.3 Italy 

18:25 44 N 9 E 10 — Italy 

18:36 35 N 51 E 10 — Iran 

18:46 44 N 8 E 10 1.7 Italy 

19:04 40 N 29 E 5 — Turkey 

19:50 44 N 7 E 10 1.7 Italy 

South Latitudes and West Longitudes 

7:49 22 S 179 W 600 5.2 Fiji Islands region 

9:38 24 S 180 W 541 4.8 South of Fiji Islands 

19:31 33 S 72 W 10 — Off coast, Chile 

South Latitudes and East Longitudes 

14:10 9 S 107 E 32 4.7 South of Java 

14:49 11 S 161 E 37 5.2 Solomon Islands 

16:07 7 S 125 E 527 5.2 Banda Sea 

17:21 19 S 167 E 10 5.2 New Hebrides 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 201 S EISMIC S LEUTHS
MASTER PAGE 

Table 2. Earthquakes That Occurred on January 2, 1990 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** Location 

North Latitudes and West Longitudes 

6:30 43 N 1 W 10 1.0 Pyrenees 

8:01 37 N 122 W 10 2.5 California 

9:50 34 N 117 W 13 3.4 California 

11:41 63 N 150 W 109 — Alaska 

12:13 61 N 146 W 32 — Alaska 

12:54 62 N 151 W 55 — Alaska 

13:50 43 N 1 W 10 1.2 Pyreness 

17:45 37 N 115 W 5 3.1 Nevada 

22:09 46 N 111 W 1 3.7 Montana 

North Latitudes and East Longitudes 

0:15 44 N 7 E 10 1.6 Italy 

1:25 8 N 127 E 41 5.4 Philippine Islands 

4:10 45 N 7 E 10 1.6 Italy 

6:26 23 N 121 E 10 — Taiwan 

8:23 40 N 27 E 10 — Turkey 

13:23 36 N 146 E 33 — Off coast, Honshu Japan 

15:20 8 N 127 E 69 4.4 Philippine Islands 

16:26 45 N 146 E 73 4.6 Kuril Islands 

16:44 44 N 7 E 10 1.9 France 

17:50 39 N 28 E 10 — Turkey 

18:50 48 N 17 E 10 2.1 Austria 

20:21 13 N 144 E 136 5.7 Mariana Islands 

20:35 39 N 24 E 10 4.6 Aegean Sea 

20:43 44 N 7 E 10 1.7 Italy 

21:03 39 N 24 E 10 — Greece 

21:38 41 N 79 E 10 4.9 Xinjiand, China 

21:46 36 N 27 E 5 3.6 Dodecanese Islands 

22:36 44 N 7 E 10 1.7 Italy 

22:54 43 N 28 E 13 — Bulgaria 

22:57 44 N 7 E 10 1.7 Italy 

23:24 37 N 26 E 26 4.4 Dodecanese Islands 

South Latitudes and West Longitudes 

2:19 22 S 13 W 10 4.7 Atlantic Ridge 

6:44 25 S 70 W 33 — Chile 

12:14 31 S 69 W 10 — Argentina 

20:51 33 S 72 W 10 4.7 Off coast, Chile 

South Latitudes and East Longitudes 

1:36 38 S 175 E 249 — New Zealand 

2:27 12 S 122 E 33 4.1 Sulu Sea 

4:33 3 S 146 E 33 4.6 Bismarck Sea 

7:02 19 S 169 E 243 4.7 New Hebrides 

7:36 11 S 166 E 140 4.7 Santa Cruz Islands 

8:22 6 S 146 E 33 5.1 Near Papua, New Guinea 

15:34 3 S 129 E 33 4.7 Ceram Sea 

21:38 3 S 128 E 34 5.4 Ceram Sea 

AGU / FEMA 202 S EISMIC S LEUTHS
MASTER PAGE 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 203 S EISMIC S LEUTHS
MASTER PAGE 

Table 3. Earthquakes That Occurred on January 1, 1991 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** Location 

North Latitudes and West Longitudes 

0:06 18 N 106 W 35 6.6 Off coast, Mexico 

2:19 18 N 106 W 33 5.0 Off coast, Mexico 

3:19 18 N 106 W 36 5.9 Off coast, Mexico 

10:28 39 N 120 W 12 3.4 California/Nevada 

15:50 55 N 158 W 33 5.2 Alaska 

16:59 61 N 152 W 97 — Alaska 

17:21 4 N 76 W 97 3.5 Colombia 

19:49 4 N 76 W 10 2.6 Colombia 

North Latitudes and East Longitudes 

0:11 35 N 28 E 42 4.9 Dodecanese Islands 

3:51 43 N 19 E 10 4.0 Yugoslavia 

4:18 40 N 24 E 10 — Greece 

4:50 29 N 139 E 402 4.4 South Honshu, Japan 

5:53 44 N 19 E 13 2.8 Yugoslavia 

7:29 48 N 8 E 10 2.6 Switzerland 

7:30 41 N 23 E 10 — Greece 

8:25 38 N 22 E 10 2.8 Greece 

9:26 38 N 22 E 19 2.8 Greece 

10:42 23 N 144 E 25 5.2 Volcano Islands 

12:01 43 N 19 E 10 2.0 Yugoslavia 

12:06 36 N 141 E 58 5.1 Off coast, Honshu, Japan 

12:14 1 N 126 E 78 4.4 Molucca Passage 

14:03 39 N 15 E 28 — Adriatic Sea 

14:25 43 N 19 E 10 2.2 Yugoslavia 

16:31 37 N 30 E 10 — Turkey 

17:43 43 N 22 E 10 2.1 Yugoslavia 

19:18 43 N 22 E 10 1.9 Yugoslavia 

19:18 40 N 48 E 61 4.9 Iran—Northern border 

19:28 48 N 8 E 10 2.2 Switzerland 

19:55 41 N 23 E 10 1.8 Macedonia 

19:55 40 N 29 E 10 2.8 Turkey 

20:40 5 N 96 E 66 4.6 Sumatra 

23:57 37 N 71 E 33 4.2 Afghanistan—N.W. border 

South Latitudes and West Longitudes 

2:03 10 S 78 W 33 4.2 Off coast, Peru 

8:27 29 S 70 W 121 4.9 Chile/Argentina 

11:15 15 S 172 W 33 4.9 Samoa Islands 

16:42 17 S 69 W 188 4.4 Peru/Bolivia 

17:28 21 S 174 W 29 5.7 Tonga Islands 

20:40 20 S 177 W 487 5.1 Fiji Islands 

South Latitudes and East Longitudes 

3:03 19 S 134 E 10 — Australia 

5:09 7 S 156 E 41 4.9 Solomon Islands 

14:10 17 S 177 E 33 4.4 Fiji Islands 

21:37 3 S 38 E 10 4.2 Kenya 

AGU / FEMA 204 S EISMIC S LEUTHS
MASTER PAGE 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 205 S EISMIC S LEUTHS
MASTER PAGE 

Table 4. Earthquakes That Occurred on January 2, 1991 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** Location 

North Latitudes and West Longitudes 

1:27 4 N 76 W 33 3.1 Colombia 

1:42 3 N 75 W 33 3.7 Colombia 

5:31 37 N 119 W 2 3.1 California/Nevada 

5:37 14 N 93 W 59 4.8 Off coast, Mexico 

8:30 6 N 74 W 10 — Colombia 

10:16 59 N 137 W 9 — Alaska 

12:07 39 N 120 W 7 3.5 Nevada 

12:16 39 N 120 W 2 2.3 Nevada 

12:26 39 N 120 W 8 3.4 Nevada 

12:46 39 N 120 W 6 3.4 Nevada 

14:38 4 N 77 W 33 3.1 Coast of Colombia 

16:29 39 N 120 W 3 3.8 Nevada 

16:59 62 N 150 W 41 — Alaska 

17:21 4 N 76 W 10 4.2 Colombia 

19:49 4 N 76 W 110 2.8 Colombia 

21:02 3 N 80 W 33 2.1 Galapagos Islands 

21:17 4 N 76 W 10 2.7 Colombia 

22:19 66 N 26 W 10 4.9 Iceland 

23:16 39 N 120 W 6 4.7 Nevada 

23:23 37 N 4 W 10 2.4 Spain 

23:44 39 N 120 W 10 3.5 Nevada 

North Latitudes and East Longitudes 

0:13 43 N 29 E 10 — Black Sea 

1:08 40 N 20 E 10 2.9 Greece/Albania 

1:34 59 N 161 E 33 4.5 Coast, Kamchatka 

2:48 53 N 161 E 33 4.5 Coast, Kamchatka 

2:58 38 N 100 E 13 5.1 Qinghai, China 

5:37 43 N 21 E 10 2.4 Yugoslavia 

7:17 30 N 21 E 5 3.5 Greece 

8:37 48 N 155 E 33 4.4 Kuril Islands 

9:35 40 N 29 E 10 2.7 Turkey 

12:16 41 N 22 E 10 — Greece 

12:51 43 N 6 E 10 2.8 France 

12:59 41 N 23 E 10 — Greece 

14:02 40 N 28 E 10 2.8 Turkey 

14:04 41 N 22 E 10 — Albania 

15:48 40 N 29 E 10 2.7 Turkey 

18:48 46 N 3 E 10 2.2 France 

20:29 45 N 1 E 10 3.0 France 

23:16 39 N 24 E 10 2.8 Aegean Sea 

23:19 24 N 121 E 10 3.6 Taiwan 

South Latitudes and West Longitudes 

1:48 22 S 69 W 33 — Chile/Bolivia 

4:54 18 S 79 W 115 — Coast of Chile 

15:16 23 S 66 W 10 — Argentina 

16:58 20 S 71 W 46 5.0 Coast of Chile 

18:30 34 S 179 W 33 4.7 Kermadec Islands 

South Latitudes and East Longitudes 

3:50 11 S 167 E 33 5.0 Santa Cruz 

AGU / FEMA 206 S EISMIC S LEUTHS
MASTER PAGE 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 207 S EISMIC S LEUTHS
MASTER PAGE 

Table 5. Earthquakes That Occurred on January 1, 1992 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** Location 

North Latitudes and West Longitudes 

1:11 41 N 124 W 5 3.0 California 

5:35 20 N 70 W 33 — Dominican Republic 

9:09 35 N 118 W 10 3.2 California 

13:43 60 N 154 W 168 3.4 Alaska 

14:28 37 N 119 W 5 2.9 California/Nevada 

16:44 16 N 61 W 33 2.8 Leeward Islands 

17:03 36 N 118 W 5 3.0 California 

17:10 38 N 4 W 10 2.9 Spain 

19:15 15 N 92 W 10 — Mexico/Guatemala 

20:39 60 N 153 W 101 — Alaska 

21:11 13 N 90 W 33 — Off El Salvador 

22:30 71 N 8 W 10 4.2 Jan Meyer Islands 

23:46 18 N 99 W 10 — Mexico 

23:55 39 N 1 W 5 2.7 Spain 

North Latitudes and East Longitudes 

0:50 45 N 7 E 10 2.1 Italy 

5:54 54 N 159 E 92 4.3 Kamchatka 

7:47 45 N 151 E 29 4.9 Kuril Islands 

8:00 43 N 18 E 10 2.6 NW Balkan region 

8:03 68 N 15 E 10 3.6 Norway 

8:13 45 N 152 E 33 4.7 East of Kuril Islands 

8:38 68 N 15 E 10 2.6 Norway 

8:41 43 N 13 E 10 — Italy 

10:07 43 N 19 E 10 1.9 NW Balkan region 

10:12 45 N 10 E 10 3.4 Italy 

10:15 68 N 15 E 10 2.5 Norway 

10:30 42 N 19 E 10 1.2 NW Balkan region 

11:28 43 N 2 E 10 3.2 Pyrenees 

11:38 45 N 10 E 10 — Italy 

14:45 42 N 20 E 5 2.2 NW Balkan region 

15:18 43 N 18 E 8 4.3 NW Balkan region 

16:34 38 N 7 E 10 3.9 Mediterranean Sea 

16:38 14 N 96 E 33 4.1 Near Andaman Islands 

16:40 44 N 10 E 10 2.7 Italy 

17:32 41 N 24 E 5 — Greece 

21:23 45 N 11 E 18 2.6 Italy 

21:35 43 N 19 E 10 1.7 NW Balkan region 

21:46 26 N 100 E 33 4.4 Yunnan, China 

22:01 43 N 18 E 5 2.4 NW Balkans 

South Latitudes and West Longitudes 

3:32 34 S 71 W 70 3.4 Chile/Argentina 

5:38 19 S 69 W 106 4.9 Chile 

11:04 34 S 71 W 33 3.2 Chile 

17:49 34 S 72 W 10 3.4 Chile 

19:45 24 S 174 W 33 4.5 Tonga Islands 

22:46 23 S 179 W 600 4.4 So. of Fiji Islands 

23:43 22 S 178 W 366 4.9 So. of Fiji Islands 

South Latitudes and East Longitudes 

15:30 8 S 155 E 370 4.4 Solomon Islands 

AGU / FEMA 208 S EISMIC S LEUTHS
MASTER PAGE 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 209 S EISMIC S LEUTHS
MASTER PAGE 

Table 6. Earthquakes That Occurred on January 2, 1992 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** Location 

North Latitudes and West Longitudes 

0:05 54 N 161 W 33 4.6 Alaska 

6:10 18 N 61 W 10 3.4 Leeward Islands 

7:42 35 N 119 W 10 2.3 California 

11:41 62 N 150 W 45 3.1 Alaska 

11:45 33 N 105 W 5 5.0 New Mexico 

13:32 11 N 63 W 109 4.4 Venezuela 

14:13 65 N 134 W 10 3.8 Yukon 

16:05 62 N 146 W 34 3.1 Alaska 

16:40 49 N 129 W 10 6.0 West of Vancouver Island 

18:12 16 N 61 W 55 4.4 Leeward Islands 

19:16 11 N 64 W 33 3.9 Coast of Venezuela 

19:41 6 N 74 W 134 5.8 Colombia 

21:29 16 N 60 W 22 2.9 Leeward Islands 

22:09 49 N 129 W 10 3.9 West of Vancouver Island 

North Latitudes and East Longitudes 

0:05 51 N 98 E 45 4.7 Russia/Mongolia 

2:15 44 N 6 E 7 3.0 France 

2:35 34 N 89 E 33 4.8 Tibet/China 

4:07 51 N 98 E 32 4.7 Russia/Mongolia 

5:28 51 N 98 E 33 — Russia/Mongolia 

5:37 41 N 71 E 33 5.2 Tajkistan 

5:50 41 N 72 E 33 4.5 Kyrgyzstan 

6:09 46 N 2 E 10 1.4 France 

6:36 37 N 29 E 10 — Turkey 

8:09 41 N 20 E 5 2.9 Albania 

10:20 46 N 27 E 137 — Romania 

10:49 45 N 152 E 33 4.7 East of Kuril Islands 

12:30 45 N 10 E 25 3.5 Italy 

12:59 51 N 98 E 33 4.6 Russia/Mongolia 

13:44 45 N 10 E 27 3.5 Italy 

17:06 35 N 27 E 63 3.9 Crete 

19:59 13 N 125 E 33 4.9 Philippine Islands 

21:17 0 N 122 E 167 4.7 Celebes 

22:06 50 N 98 E 33 — Russia/Mongolia 

23:13 45 N 146 E 110 4.5 Kuril Islands 

23:55 39 N 1 E 10 — Spain 

South Latitudes and West Longitudes 

1:47 34 S 70 W 10 4.3 Chile/Argentina 

4:25 33 S 71 W 10 3.3 Chile 

23:21 27 S 68 W 33 — Chile/Argentina 

South Latitudes and East Longitudes 

3:28 6 S 150 E 59 4.4 New Britain 

4:49 7 S 151 E 51 4.8 New Britain 

6:17 9 S 150 E 33 4.1 New Guinea 

7:41 6 S 150 E 33 4.3 New Britain 

22:17 22 S 180 E 673 4.6 So. of Fiji Islands 

23:33 32 S 111 E 33 — West of Australia 

23:37 38 S 176 E 238 — New Zealand 

AGU / FEMA 210 S EISMIC S LEUTHS
MASTER PAGE 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 211 S EISMIC S LEUTHS
MASTER PAGE 

Table 7. Earthquakes That Occurred on January 1, 1993 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** 

North Latitudes and West Longitudes 

2:09 36 N 5 W 10 Strait of Gibraltar 

4:12 60 N 153 W 10 3.1 

Location 

2.9 

Alaska 

5:08 36 N 82 W 4 3.0 North Carolina 

5:36 31 N 114 W 10 3.6 Gulf of California 

6:07 18 N 64 W 10 4.0 Virgin Islands 

14:55 64 N 149 W 6 2.8 Alaska 

15:57 48 N 112 W 5 3.4 Montana 

North Latitudes and East Longitudes 

1:35 39 N 29 E 10 2.7 Turkey 

2:05 39 N 29 E 10 2.8 Turkey 

2:23 4 N 126 E 86 4.4 Talaud Islands 

4:18 39 N 22 E 10 — Greece 

4:30 53 N 158 E 170 4.2 Kamchatka 

5:35 38 N 15 E 10 — Sicily 

5:40 43 N 6 E 10 2.4 Coast of France 

5:43 44 N 8 E 10 — Italy 

7:30 39 N 29 E 10 2.8 Turkey 

8:19 39 N 143 E 37 4.7 Coast of Japan 

14:25 38 N 27 E 10 3.1 Turkey 

16:11 42 N 20 E 10 2.7 Albania 

18:46 42 N 14 E 10 3.8 Italy 

19:16 45 N 7 E 10 2.0 Italy 

20:49 38 N 27 E 10 3.1 Aegean Sea 

21:00 43 N 5 E 10 3.6 Coast of France 

21:26 3 N 122 E 536 4.4 Celebes Sea 

21:46 35 N 33 E 13 3.4 Cyprus region 

23:49 23 N 95 E 96 4.3 India/Myanmar 

South Latitudes and West Longitudes 

3:46 32 S 178 W 33 5.1 Kermadec Islands 

4:02 32 S 68 W 100 — Argentina 

4:34 31 S 179 W 48 4.7 Kermadec Islands 

5:48 28 S 177 W 65 4.7 Kermadec Islands 

8:26 33 S 176 W 33 4.7 So. of Kermadec Islands 

9:17 32 S 69 W 120 3.5 Argentina 

9:56 32 S 72 W 27 5.4 Chile 

10:06 36 S 74 W 100 4.0 Chile 

13:09 25 S 178 W 203 5.2 So. of Fiji Islands 

17:29 31 S 68 W 10 — Argentina 

South Latitudes and East Longitudes 

2:56 26 S 28 E 5 2.5 Rep. of So. Africa 

5:00 7 S 128 E 33 — Banda Sea 

5:19 7 S 131 E 68 4.6 Banda Sea 

6:24 6 S 147 E 74 4.7 New Guinea 

8:58 7 S 144 E 23 5.2 New Guinea 

10:56 7 S 132 E 122 — Indonesia 

12:35 39 S 177 E 59 4.4 New Zealand 

12:48 38 S 179 E 182 — New Zealand 

21:36 67 S 164 E 10 5.6 Balleny Islands 

AGU / FEMA 212 S EISMIC S LEUTHS
MASTER PAGE 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 213 S EISMIC S LEUTHS
MASTER PAGE 

Table 8. Earthquakes That Occurred on January 2, 1993 

as listed in “Preliminary Determinations of Epicenters,” USGS-NEIC 

Time* Latitude Longitude Depth (in km) Magnitude** Location 

North Latitudes and West Longitudes 

1:57 7 N 76 W 24 4.5 Colombia 

2:39 7 N 80 W 10 4.3 So. of Panama 

5:45 19 N 67 W 19 — Mona Passage 

6:03 18 N 66 W 70 — Puerto Rico 

6:39 45 N 111 W 5 3.5 Yellowstone, WY 

6:44 10 N 83 W 10 3.8 Panama/Costa Rica 

7:09 61 N 150 W 41 2.5 Alaska 

8:54 62 N 151 W 72 — Alaska 

9:49 60 N 153 W 122 — Alaska 

14:32 39 N 124 W 3 3.1 California 

North Latitudes and East Longitudes 

1:48 39 N 29 E 10 3.1 Turkey 

2:32 39 N 29 E 10 2.6 Turkey 

3:42 31 N 50 E 33 4.3 Iran 

7:55 44 N 6 E 10 2.2 Coast of France 

8:39 30 N 51 E 36 4.7 Iran 

14:53 29 N 81 E 15 4.9 Nepal 

15:10 34 N 142 E 44 4.6 Coast of Japan 

17:45 37 N 24 E 33 3.3 Greece 

22:09 46 N 3 E 10 1.9 France 

22:38 41 N 23 E 10 — Greece 

South Latitudes and West Longitudes 

3:09 31 S 69 W 132 — Chile/Argentina 

4:04 30 S 177 W 10 4.9 Kermadec Islands 

6:15 33 S 71 W 80 3.1 Chile/Argentina 

11:35 34 S 71 W 33 4.2 Chile 

13:40 34 S 71 W 60 3.3 Chile 

14:31 33 S 72 W 25 3.4 Chile 

15:00 33 S 72 W 10 3.1 Chile 

16:24 33 S 71 W 33 3.5 Chile 

17:48 29 S 67 W 161 — Argentina 

South Latitudes and East Longitudes 

1:07 38 S 176 E 253 — New Zealand 

4:55 9 S 121 E 84 4.5 Savu Sea 

6:29 40 S 86 E 10 5.5 SE Indian Ridge 

9:30 7 S 129 E 173 3.8 Banda Sea 

9:49 9 S 123 E 150 4.3 Indonesia 

11:12 39 S 176 E 142 — New Zealand 

12:32 38 S 176 E 224 5.0 New Zealand 

17:56 6 S 151 E 54 4.1 New Britain 

19:01 7 S 130 E 33 — Banda Sea 

19:29 39 S 175 E 249 — New Zealand 

*Greenwich time. 

**Value is the maximum magnitude determined for the event. A dash indicates that data were not available. 

AGU / FEMA 214 S EISMIC S LEUTHS
MASTER PAGE Notable World Earthquakes 

1900 – 1992*

3.4b 

Time Latitude Longitude Depth (in km)** Magnitude Location Deaths 

North Latitudes and West Longitudes 

4/18/06 38 N 123 W — 8.3 San Francisco, CA 700 

2/29/60 30 N 10 W — 5.9 Morocco 14,000 

3/28/64 61 N 148 W 33 8.5 Alaska 131 

2/9/71 34 N 118 W 13 6.7 San Fernando, CA 65 

12/23/72 12 N 86 N 5 6.2 Nicaragua 5,000 

2/4/76 15 N 89 W 5 7.5 Guatemala 22,000 

9/19/85 18 N 103 W — 8.1 Mexico 9,500 

10/10/86 14 N 89 W 8 5.4 El Salvador 1,000 

3/6/87 0 N 78 W 33 6.9 Ecuador 1,000 

10/18/89 37 N 122 W 19 7.1 Loma Prieta, CA 63 

6/28/92 34 N 117 W — 7.1 Landers, CA 1 

North Latitudes and West Longitudes 

12/28/08 38 N 15 E — 7.5 Messina, Italy 120,000 

1/13/15 42 N 13 E — 7.5 Central Italy 30,000 

12/16/20 37 N 106 E — 8.5 China 180,000 

9/1/23 35 N 140 E — 8.2 Kwanio, Japan 143,000 

12/25/32 40 N 97 E — 7.6 China 

12/26/39 40 N 40 E — 8.0 Turkey 23,000 

6/28/48 36 N 136 E 20 7.3 Honshu, Japan 5,121 

9/1/62 36 N 50 E 20 7.3 Iran 14,000 

7/26/63 42 N 22 E 5 6.0 Macedonia 1,200 

8/31/68 34 N 59 E 13 7.3 Iran 11,600 

2/4/75 41 N 123 E 33 7.4 China “Few” 

5/6/76 46 N 13 E 9 6.5 Italy 

7/14/76 40 N 118 E 23 7.8 Tangshan, China 250,000 

3/3/77 46 N 27 E 94 7.2 Romania 2,000 

10/10/80 36 N 1 E 10 7.4 Algeria 

11/23/80 41 N 15 E 10 6.9 Italy 3,000 

6/11/81 30 N 58 E 33 6.9 Iran 3,000 

7/28/81 30 N 58 E 33 7.3 Iran 1,500 

5/28/83 41 N 139 E 24 7.8 Japan 107 

10/30/83 40 N 42 E 33 6.9 Turkey 1,342 

8/20/88 27 N 87 E 71 6.6 Nepal 1,450 

11/6/88 23 N 100 E 10 7.6 Burma 730 

12/7/88 41 N 44 E 10 6.8 Armenia 25,000 

6/20/90 38 N 50 E 10 7.6 Iran <40,000 

7/16/90 16 N 121 E 36 7.7 Philippines 1,700 

South Latitudes and West Longitudes 

1/25/39 36 S 72 W 60 8.3 Chillan, Chile 30,000 

8/6/49 2 S 78 W 60 6.8 Ecuador 6,000 

5/22/60 40 S 73 W — 8.5 Chile 5,700 

5/31/70 9 S 79 W 43 7.8 Peru 66,000 

12/12/79 2 S 79 W 32 7.9 Ecuador 600 

3/3/85 33 S 72 W — 7.8 Chile 177 

South Latitudes and East Longitudes 

8/5/49 2 S 119 E 3 8.0 Indonesia 3 

8/1/89 5 S 139 E 33 5.9 New Guinea 90 

12/27/89 33 S 152 E 15 5.4 Australia 13 

AGU / FEMA 215 S EISMIC S LEUTHS
MASTER PAGE Notable World Earthquakes 

1900 – 1992*

3.4b 

*From Bolt, 1993, and “Catalog of Significant Earthquakes 2000 B.C.-1990,” a NOAA publication in preparation. 

**Where data are lacking, assume earthquakes were shallow.

AGU / FEMA 216 S EISMIC S LEUTHS
AGU / FEMA 217 S EISMIC S LEUTHS
3.4c MASTER PAGE World Map

AGU / FEMA 218 S EISMIC S LEUTHS
MASTER PAGE 

AGU / FEMA 219 S EISMIC S LEUTHS
3.4d MASTER PAGE Central Japan

AGU / FEMA 220 S EISMIC S LEUTHS
MASTER PAGE 

AGU / FEMA 221 S EISMIC S LEUTHS
MASTER PAGE Selected

Since 1980, Japan

3.4e 

This is a listing of events of Magnitude 5 which occurred in the polygon bounded by 34N 144E, 38N 134E, 39N 136E, and 35N 146E, centered around 

Tokyo, Japan. Data are from 1980 to 1993. Use the reference number in the first column (under the heading Evt. for Event) to mark the location of each 

earthquake on your map. 

Evt Mo Da Hr Min Yr Lat Long Dpth Mag #Stns 

1 12 7 9 38 90 37.22 N 138.48 E 10 5.4 179 

2 12 30 0 38 86 36.66 N 137.89 E 10 5.5 260 

3 2 7 13 27 93 37.63 N 137.25 E 11 6.6 673 

4 8 9 0 46 82 35.67 N 142.02 E 13 5.5 293 

5 8 26 15 43 85 36.21 N 142.35 E 13 5.5 267 

6 7 23 17 54 82 36.10 N 141.89 E 14 6.2 499 

7 2 15 16 51 93 37.61 N 137.26 E 15 5.0 117 

8 12 7 9 40 90 37.31 N 138.46 E 15 5.1 64 

9 10 16 10 39 83 37.19 N 137.91 E 17 5.1 93 

10 4 8 4 34 89 36.38 N 141.96 E 21 5.0 67 

11 3 24 12 49 87 37.44 N 137.86 E 23 5.7 339 

12 12 13 10 13 90 35.50 N 140.93 E 23 5.0 59 

13 7 23 15 5 82 36.19 N 141.97 E 24 5.1 169 

14 5 22 13 31 82 35.22 N 141.22 E 25 5.0 51 

15 10 18 3 22 85 37.64 N 136.90 E 25 5.9 546 

16 8 6 14 49 91 35.72 N 141.04 E 29 5.9 404 

17 5 9 16 51 87 36.22 N 141.89 E 30 5.2 365 

18 7 16 10 8 90 36.12 N 141.35 E 33 5.0 108 

19 5 18 15 31 81 37.02 N 137.71 E 35 5.4 28 

20 1 6 18 52 88 36.38 N 141.80 E 36 5.0 172 

21 7 25 9 10 82 36.21 N 142.03 E 36 5.0 86 

22 8 23 16 40 82 36.35 N 141.48 E 36 5.8 273 

23 7 23 14 23 82 36.19 N 141.70 E 37 6.8 271 

24 9 3 19 39 81 35.29 N 141.08 E 37 5.7 378 

25 2 10 16 23 87 35.58 N 143.01 E 38 5.2 114 

26 10 4 4 11 81 35.23 N 140.96 E 38 5.0 85 

27 7 25 8 1 82 36.41 N 141.79 E 39 5.5 454 

28 1 17 11 13 84 36.44 N 141.22 E 40 5.6 218 

29 11 28 22 29 86 36.34 N 141.17 E 41 5.7 272 

30 2 11 17 46 90 36.33 N 140.91 E 46 5.4 228 

31 12 8 17 23 89 36.55 N 140.91 E 47 5.4 235 

32 1 29 2 44 83 36.70 N 141.51 E 50 5.1 166 

33 3 11 3 1 85 36.41 N 141.01 E 50 5.8 179 

34 8 6 5 58 85 36.44 N 141.03 E 50 5.3 307 

35 8 15 16 58 82 36.49 N 141.03 E 50 5.4 223 

36 10 2 0 32 83 36.46 N 141.18 E 50 5.1 145 

37 1 27 1 30 87 35.57 N 140.94 E 51 5.1 277 

38 7 23 14 29 82 36.37 N 141.24 E 51 5.3 87 

39 9 2 9 24 81 35.82 N 141.02 E 51 5.6 443 

40 9 13 1 20 81 36.14 N 141.17 E 51 5.0 218 

41 3 16 0 45 84 36.76 N 141.56 E 52 5.0 179 

42 6 4 21 11 84 36.45 N 141.18 E 52 5.0 157 

43 12 1 16 15 80 35.90 N 140.95 E 52 5.0 118 

AGU / FEMA 222 S EISMIC S LEUTHS
MASTER PAGE Selected

Since 1980, Japan

3.4e 

44 1 3 10 2 88 35.33 N 140.88 E 53 5.0 67 

AGU / FEMA 223 S EISMIC S LEUTHS
MASTER PAGE 

45 8 13 21 14 82 36.53 N 141.11 E 55 5.4 381 

46 4 14 3 3 92 36.17 N 139.78 E 57 5.0 158 

47 9 2 3 5 83 36.68 N 141.01 E 57 5.2 227 

48 12 30 2 30 83 35.69 N 140.66 E 58 5.4 378 

49 5 11 10 7 92 36.46 N 140.52 E 59 5.2 208 

50 8 13 21 15 82 36.45 N 140.93 E 59 5.4 194 

51 2 13 10 1 87 36.64 N 140.96 E 60 5.1 324 

52 2 19 12 27 88 35.96 N 139.78 E 60 5.5 287 

53 9 10 15 25 83 35.60 N 140.64 E 60 5.0 45 

54 2 3 10 11 88 36.57 N 141.13 E 62 5.0 22 

55 6 25 3 49 91 36.60 N 140.88 E 62 5.0 147 

56 8 27 4 9 92 36.11 N 139.81 E 63 5.0 132 

57 5 3 7 45 90 36.44 N 140.51 E 64 5.4 269 

58 6 10 2 0 80 35.89 N 139.55 E 64 5.1 64 

59 10 15 2 58 83 36.11 N 139.81 E 64 5.1 52 

60 5 28 17 58 92 35.63 N 140.52 E 65 5.0 131 

61 9 20 3 4 86 36.47 N 140.70 E 66 5.1 252 

62 1 7 18 18 83 36.07 N 139.87 E 67 5.1 168 

63 6 1 1 22 90 35.52 N 140.33 E 67 5.8 367 

64 6 29 22 9 84 36.17 N 139.79 E 67 5.4 22 

65 7 26 4 30 84 36.17 N 139.98 E 67 5.0 88 

66 12 5 19 47 84 36.41 N 140.66 E 67 5.0 82 

67 2 21 23 23 81 36.47 N 140.72 E 68 5.0 146 

68 3 6 23 14 82 36.48 N 140.61 E 68 5.6 386 

69 4 10 10 59 87 36.12 N 139.81 E 68 5.1 287 

70 6 30 9 17 87 36.17 N 139.98 E 70 5.0 159 

71 10 28 1 50 83 36.21 N 139.98 E 70 5.2 247 

72 3 10 0 37 87 36.44 N 140.83 E 76 5.1 122 

73 2 27 12 14 83 35.93 N 140.08 E 78 5.9 566 

74 4 17 7 33 87 35.72 N 140.07 E 78 5.1 324 

75 10 10 6 28 88 35.56 N 140.10 E 78 5.0 152 

76 7 3 18 3 90 35.92 N 140.04 E 79 5.1 139 

77 12 17 14 49 84 35.57 N 140.09 E 81 5.1 204 

78 2 21 11 51 84 36.15 N 140.09 E 83 5.1 241 

79 10 4 12 25 85 35.84 N 140.09 E 83 6.2 648 

80 9 23 19 10 80 35.98 N 139.78 E 88 5.4 362 

81 11 9 23 37 82 36.57 N 140.62 E 111 5.0 72 

82 7 14 14 19 91 36.41 N 138.33 E 188 5.2 102 

83 9 18 21 42 88 37.15 N 136.96 E 262 5.1 276 

84 5 17 1 4 90 37.06 N 136.88 E 267 5.2 340 

85 3 11 22 22 84 38.39 N 135.48 E 351 5.3 307 

AGU / FEMA 224 S EISMIC S LEUTHS
3.4f MASTER PAGE North American Epicenters, 1990

 

MO. DAY TIME 

(UTC) 

LAT. 

(N) 

LONG. 

(W) 

DEPTH 

(KM) 

MAGNITUDE 

01 11 0122 35.22 118.22 4 4.1 

01 13 0547 30.22 114.44 10 4.6 

01 13 2005 27.60 115.09 10 5.1 

01 15 0529 37.99 118.21 5 5.0 

01 24 1820 38.13 86.43 5 4.1 

01 26 0220 26.08 110.12 10 4.8 

01 27 0628 30.12 113.73 10 4.2 

01 28 0459 43.31 102.50 5 4.0 

01 29 1316 34.46 106.88 12 4.8 

01 31 0108 34.44 106.86 10 4.0 

02 18 1552 33.51 116.45 9 4.1 

02 28 2343 34.14 117.70 5 6.2 

03 01 0323 34.15 117.72 11 4.8 

03 02 1726 34.14 117.69 6 4.6 

03 07 0716 37.47 118.62 11 4.0 

03 10 1600 37.11 116.06 0 5.1 

03 10 1726 37.11 116.06 0 4.0 

03 16 1552 24.90 109.04 10 6.1 

03 16 1646 24.40 108.80 10 4.7 

03 20 0707 24.50 109.10 10 4.3 

03 31 2259 32.38 115.24 6 4.3 

04 04 0854 32.97 117.81 6 4.5 

04 17 2232 34.11 117.72 4 4.7 

05 20 1715 20.27 63.26 78 4.3 

06 11 0452 27.39 111.26 10 4.8 

06 13 1600 37.26 116.42 0 5.7 

06 21 1047 33.16 115.63 1 4.0 

06 21 1815 36.99 116.00 0 4.3 

07 12 0903 24.02 108.52 10 4.7 

07 12 1327 23.02 108.96 10 4.2 

07 25 1500 37.21 116.21 0 4.7 

08 17 2101 36.79 83.34 10 4.0 

08 31 0338 33.25 116.05 8 4.2 

09 06 0524 27.20 110.56 10 4.1 

09 26 1318 37.17 89.58 12 5.0 

10 11 0314 21.18 99.69 10 4.0 

10 12 1730 37.25 116.49 0 5.6 

10 13 0356 31.72 115.91 6 4.0 

10 19 0701 46.47 75.59 13 5.1 

10 24 0615 38.05 119.16 12 5.7 

10 25 0324 23.83 108.71 10 5.1 

11 05 0716 38.03 119.17 10 4.2 

11 08 1046 34.45 106.86 6 4.4 

11 14 1917 37.23 116.37 0 5.4 

11 15 1347 47.13 76.22 18 4.1 

11 28 0248 38.67 116.46 10 4.3 

11 30 1130 47.77 113.16 5 4.0 

12 18 1656 35.37 118.85 6 4.2 

12 24 0254 44.78 111.20 5 4.0 

12 31 0353 47.58 72.56 18 4.4 

AGU / FEMA 225 S EISMIC S LEUTHS
AGU / FEMA 226 S EISMIC S LEUTHS
3.4g MASTER PAGE Map of North America

AGU / FEMA 227 S EISMIC S LEUTHS
AGU / FEMA 228 S EISMIC S LEUTHS
3 UNIT RESOURCES 

To obtain U.S. Department of the Interior/U.S. 

Geological Survey Preliminary Determinations of 

Epicenters, write to the Superintendent of Documents, 

U.S. Government Printing Office, Washington, DC 

20402. Annual subscription, $21. 

BOOKS AND REPORTS 

Bolt, Bruce A. (1993). Earthquakes. New York: W.H. 

Freeman & Co. Probably the single most useful basic 

text on earthquakes. 

Christman, Robert A. (1980). “Epicenters of the 1964 

Alaskan Earthquake” and “Time Travel: Earthquake 

Waves and Horses.” In Activities for Earth Science,

edited by V. Mayor. Columbus, OH: ERIC 

Clearinghouse (1929 Kenny Road, Columbus, OH 

43210-1079; 614-292-7784). 

Davison, Charles. (1978). The Founders of 

Seismology. New York: Arno Press. 

Herbert-Gustar, A.L., and Mott, P.A. (1980). John 

Milne: Father of Modern Seismology. Tenterden, 

England: Paul Norburg Publishers Ltd. 

Penick, J. (1981). The New Madrid Earthquake of 

1811-1812, revised edition. Columbia, MO: 

University of Missouri Press. 

Ross, Katherine E., editor. Making Earthquake 

Education Come Alive—The Development and Use of 

Low Cost Models in the Classroom. Buffalo, NY: 

NCEER, State University of New York; 716-636- 

3391. In press. 

Simon, Ruth B. (1981). Earthquake Interpretation: A 

Manual for Reading Seismograms. Los Altos, CA: 

Steinbrugge, K.V. (1982). Earthquakes, Volcanoes, 

and Tsunamis. New York: Scandia America Group. 

Stewart, David, and Knox, Ray. (1993). The 

Earthquake That Never Went Away. The Shaking 

Stopped in 1812, but the Impact Goes On. Marble Hill, 

MO: Gutenberg-Richter Publications. 

Utah Geological Survey. (October 1992, Revised). 

Places with Hazards. Salt Lake City, UT: Utah 

Department of Natural Resources; 801/467-7970. A 

teacher’s handbook on natural hazards in Utah for 

secondary earth science classes. Includes a geologic 

hazard slide set. Identifies and defines nine types of 

soil and rock conditions that pose geologic hazards in 

Utah and their locations. 

ARTICLES AND PAPERS 

Barker, Gary Keith. (1987). “Interfacing the Lehmann 

Seismograph with an Apple Computer.” Journal of 

Geological Education 4, 35: 126-128. Provides plans 

for interfacing the Lehmann seismograph with an 

Apple computer and printer through an analog/digital 

converter. 

Barker, Gary. (September 1983). “A Working 

Seismograph for the Classroom.” Michigan Earth 

Scientist. Journal of the Michigan Earth Science 

Teachers Association. 

“The Bigger One.” (Nov. 29, 1987). Los Angeles 

Times Magazine. A fictional account of a magnitude 

7.5 earthquake, worst-case scenario, on the NewportInglewood Fault. 

AGU / FEMA 229 S EISMIC S LEUTHS
3 UNIT RESOURCES 

William Kaufmann, Inc. 

AGU / FEMA 230 S EISMIC S LEUTHS
UNIT RESOURCES 

Brownlee, Shannon. (July 1986). “Waiting for the Big 

One.” Discover 7, 52–71. Worth looking for—a 

highly readable account of the state of earthquake 

prediction, with excellent illustrations. 

Christman, Robert A. (1975). “Understanding and 

Interpreting the Bellingham Seismograms of the 1964 

Alaskan Earthquake.” Bellingham, WA: Western 

Washington State College. Available from Creative 

Dimensions, PO Box 1393, Bellingham, WA 98227 

(206-733-5024). Design your own classroom activities 

for the interpretation and understanding of a 

seismogram. Written explanations and questions are 

included. 

Fuller, Myron L. (1990 reprint). The New Madrid 

Earthquake Scientific Factual Field Account. USGS 

Bulletin 494. Washington, DC: Government Printing 

Office, 1912. (Reprinted by the Southwestern 

Missouri University Center on Earthquake Studies) 

Gerencher, J.J., and Jackson, R.F. (1991). “Classroom 

Utilization of a Multi-Axis Lehman Seismograph 

System.” Journal of Geological Education 39: 306–

310. Also see Seismological Data Acquisition 

Software below. 

Kerr, R.A. (1979). “Earthquake Prediction: Mexican 

Quake Shows One Way to look for the Big Ones.” 

Science 201: 1001–1003. 

Kroll, Lawrence. (1987). “Construction Modifications 

of the Lehmann Seismograph.” Journal of Geological 

Education 4, 35: 124–125. Modifications and building 

tips for the Lehmann seismograph built from common 

materials. 

“Inge Lehmann.” Current Biography, 1962, pp. 251-

253. 

Plude, C. (April 1986). “Charles Richter: Earthquake 

Man.” Cobblestone, p. 22. Written for readers 8–14. 

This issue contains other articles of interest as well. 

Proujan, C. (Nov. 29, 1985). “Build a Model 

Tiltmeter—An Earthquake Warning System.” Science 

World, pp. 8–9. For ages 12–15. 

Raleigh, C.B., et al. (March 1983). “Forecasting 

Southern California Earthquakes.” California Geology 

36. California Division of Mines and Geology; 

916-323-5336. 

Simon, Ruth. “A Personal Memoir of Inge Lehmann 

(1888-1993).” Eos (November 2, 1993): 510–512. 

“Tsunami Data.” National Geophysical Data Center, 

NOAA, Code E/GCI. 325 Broadway, Boulder, CO 

80303; 303-497-633. 

Williams, R.L. (1983). “Science Tries to Break New 

Ground in Predicting Great Earthquakes.” Smithsonian

14, 4: 41-50. 

PERIODICALS 

Earthquakes and Volcanoes, a bimonthly magazine 

published by the U.S. Geological Survey, 904 National 

Center, Reston, Virginia, 22029; 703/648-6078. See 

especially “Pacific Tsunami Warning System,” 

Volume 18, Number 3, 1986, and “Devastating 

Tsunami Inspires Efforts to Reduce Future Tsunami 

Destruction,” Volume 19, Number 2, 1987. 

Eos, Transactions, American Geophysical Union. A 

weekly newspaper of geophysics. American 

Geophysical Union, 2000 Florida Avenue NW, 

Washington, DC 20009; 800-966-2481. See especially 

August 17, August 24, and September 14, 1993. 

NON-PRINT MEDIA 

EPIC Retrieval Software for the Global Hypocenter 

Data Base CD-ROM. United States Geological 

Survey, National Earthquake Information Center. A 

demonstration disk and information packet are 

available free: Phone 303- 273-8406; Fax 

303-273-8450; E-Mail hdf@neis.cr.usgs.gov 

(Internet). Federal Center, Box 25046, Mail Stop 967, 

Denver, CO 80225-0046. Through EPIC, you can 

access enormous amounts of national and international 

data ranging from 2100 BC to last month. 

Jones, Alan L. The Dynamic Seismicity Program. 

version 1.00 level 93.03.02. New York: State 

University of New York, at Binghamton, 1993. Three 

computer disks and instruction manual. Also, PC 

shareware available on Internet 

@sunquakes.geol.binghamton.edu. 

Hidden Fury: The New Madrid Quake Zone. 27-

minute video available from Bullfrog Films, 

P.O. Box 149, Oley, PA 19547; 1/800-543-FROG. 

AGU / FEMA 231 S EISMIC S LEUTHS
UNIT RESOURCES 

IRIS Database. United States Geological Survey, 

National Earthquake Information Center, Incorporated 

Research Institutions for Seismology, 1616 North Fort 

Myer Drive, Suite 1050, Arlington, VA 22209-3019. 

Seismograph Model. For sale by Nasco, 800/558-

9595. Includes a recording needle, a support with a 

suspended weight, a recording tape, and a teachers 

guide. 

Science ToolKit, Module 2: Earthquake Lab. 

Broderbund Software (Dept. 15, PO Box 6125, 

Novato, CA 94948-6125), 1986, for the Apple. 

Grades 4–12. Requires Science Toolkit Master 

Module. 

Seismological Data Acquisition Software. Described in 

the Gerencher and Jackson article above. Apple 

software and 64-page user’s manual available from 

J. J. Gerencher, Physics and Earth Sciences, Moravian 

College, 1200 Main Street, Bethlehem, PA 18018-

6650. 

Note: Inclusion of materials in these resource listings does 

not constitute an endorsement by AGU or FEMA. 

AGU / FEMA 232 S EISMIC S LEUTHS
AGU / FEMA 233 S EISMIC S LEUTHS
UNIT FOUR 
4 INTRODUCTION 

Can Buildings Be Made Safer? 

This unit is designed to allow students to construct an 

understanding of how the shaking of the ground 

during an earthquake causes damage to buildings and 

how buildings can be made better able to withstand 

this shaking. The activities and experiments of this 

unit culminate in an exciting performance assessment. 

Like the activities in Unit 1, these require considerable 

teacher preparation and will be enhanced by the widest 

possible involvement of community members outside 

the classroom. 

Lesson 1, Building Fun, is designed as an attentiongrabber, allowing students to discover the physical 

properties of some materials, practice working 

together, and most of all, have fun while establishing 

the need for constraints in building performance 

requirements. Students are given Styrofoam strips and 

a variety of connection devices and asked to build a 

stable structure of any kind. 

Lesson 2 provides students with real experience in 

reinforcing or bracing a wall to carry the horizontal 

loads of an earthquake. They learn three engineering 

techniques and experiment with them on a model wall. 

Students develop the ability to make load path 

diagrams to predict and describe how static and 

dynamic forces travel though a wall. 

Lesson 3, Building Oscillation Seismic Simulation, or 

BOSS, is an opportunity for students to explore the 

phenomenon of resonance while performing a 

scientific experiment that employs mathematical 

skills. The students are intrigued by a discrepant event 

involving the BOSS Model and are then set to work 

experimenting with the natural frequencies of 

structures. They experience how structures behave 

dynamically during an earthquake. 

Lesson 4, Earthquake in a Box, engages students in 

constructing and using an instrument similar to one 

scientists use to model the impact of earthquake 

shaking. The materials and the procedure are both 

uncomplicated. This activity reinforces the major role 

of horizontal (lateral) forces in an earthquake and the 

importance of designing structures to withstand them. 

In Lesson 5, The Building Challenge, students apply 

what they have learned in the first four activities. They 

are challenged to build a Styrofoam structure that can 

sustain the maximum horizontal load possible. The 

students’ performance in this building contest is an 

authentic assessment of the ideas developed in Unit 4. 

Take time to do all the activities in this unit with your 

class. They are all important, not only because this unit 

is more closely integrated than the other units, but also 

because it deals with an aspect of earthquake safety 

that is usually not treated elsewhere in high school and 

junior high learning materials. It will kindle your 

students’ enthusiasm for science, architecture, and 

engineering. 

AGU / FEMA 226 S EISMIC S LEUTHS
4.1 

Building Fun 

TEACHING CLUES AND CUES 

The lessons in this unit 

are a set. Plan time to 

do them all, for 

maximum learning and 

enjoyment. 

Give yourself plenty of 

time for gathering and 

cutting materials. There 

is potential for some 

mess, so leave time for the students 

to clean up.

If you are not able to 

obtain visuals to 

introduce this lesson, do 

a quick demonstration 

RATIONALE 

Students investigate the physical properties of building materials and 

design while considering how these might affect the way a structure 

withstands forces. 

FOCUS QUESTIONS 

What kind of structure would you build for fun? 

What are the properties of some uncommon building materials? 

How do structures stand up to extra forces? 

OBJECTIVES 

Students will: 

1. Build a model structure. 

2. Describe what may happen to a structure when a load is applied. 

3. Describe the physical properties of some materials. 

MATERIALS 

for the teacher 

with a deck of cards instead. Build 

card houses and let students take 

turns knocking them down by 

shaking the surface they rest on, or 

invite them to build and test the 

structures. The point is only that 

buildings need more than walls and 

a

QMaster 4.1a, Building Engineering: Teacher Background 

Information 

QPhotos, books, slides, and/or videos with images of earthquake 

damage (See Unit 1 Resources.) 

QBand saw or other saw 

QOne brick 

for each small group

Q6 or more sticks of Styrofoam, 2.5 cm x 2.5 cm x 15 cm 

l in. x 1 in. x 6 in.) 

Q3 pieces of string, each 30 cm long (optional) 

Q10 paper clips (optional) 

QAbout 20 toothpicks 

roof to withstand stress. 

AGU / FEMA 227 S EISMIC S LEUTHS
4.1 

QMasking tape for labels 

AGU / FEMA 228 S EISMIC S LEUTHS
VOCABULARY 

Horizontal load: the sum 

of horizontal forces 

(shear forces) acting on 

the elements of a 

structure. 

PROCEDURE 

Teacher Preparation 

1. You may want to invite an architect, engineer, geologist, or 

seismologist to visit your class during Lesson 4 of this unit, when 

students will again design model buildings. The guest expert could 

initiate the building challenge and help students to understand the 

concepts involved. 

2. Read the teacher background information on Master 4.1a. 1f 

possible, assemble visuals from among those listed in the Unit 1 

Resources. 

3. Draft a few students to cut the Styrofoam into pieces, or ask the 

industrial arts instructor to help. (Styrofoam is easily cut on a band 

saw.) Finally, collect the building materials for this lesson and put 

them into piles on a table in the front of the room. 

Lead: the sum of vertical force 

(gravity) horizontal forces (shear 

forces) acting on the mass of a 

structure. The overall load is further 

broken down into the loads of the 

various parts of the building. 

Different parts of a building are 

designed and constructed to carry 

different loads. 

Vertical load: the effect of vertical 

force (gravity) acting on the elements 

of a structure. 

TEACHING CLUES AND CUES

Cut more Styrofoam 

than you will need for 

this lesson—about 35 

strips per group—since 

A. Introduction 

Set the stage by asking students to tell what they know about the effect 

of earthquakes on buildings and other structures, both from personal 

experience and from reading, television, movies, or other sources. Be 

protective of their right to say what they remember, even if it may 

sound exaggerated to other students. If you have pictures or slides of 

earthquake damage, show them now. 

B. Lesson Development 

1. Divide the class into cooperative working groups of three to five 

students each. Explain that throughout this unit the groups will be 

known as seismic engineering teams, or SETs. Encourage each SET to 

choose a name. 

2. Ask the groups to collect materials and build the strongest structures 

they can with the materials and the time allotted. Do not direct or 

criticize their efforts. This activity is for fun. When students try again 

in Lesson 4, they will be able to apply what they have learned in this 

unit. 

3. After 20 to 30 minutes, call a halt to construction. Have a 

spokesperson for each group bring its structure to the materials table 

in the front of the room and describe the structure to the class. Ask 

students to explain why they built what they did. 

4. With all the structures on one table, ask the class what would 

happen if you were to place a brick on top of each structure. Have the 

brick in hand, but do not actually crush any structure. Explain to the 

students that the brick is simulating the static force of gravity (vertical 

load) that every structure must carry. In this case, the Styrofoam is 

quite strong for its weight, so the brick can also represent the weight 

of all the nonstructural elements of a building, such as floors, wall 

coverings, and electrical wiring. Expect the students to protest because 

they were not told their structures had to support a brick. Explain that 

this activity was only an introduction and a chance to discover the 

physical properties of the materials. 

you will also use these strips in 

Lesson 4. If some of the strips are 

less than uniform, use them now, 

saving the best ones for Lesson 4. 

AGU / FEMA 229 S EISMIC S LEUTHS
5. Now ask the students what would happen if you shook the base of 

each building. Test a few gently while the students observe. What if 

you held the base of each structure and pushed horizontally on the 

top? Test a few, but again, try not to break any structure. Explain that 

buildings experience horizontal loads or dynamic forces during 

earthquakes. One way to simulate these forces is simply to push or 

pull a structure from the side. 

C. Conclusion 

Tell students that at the end of this unit there will be another building 

activity, but this time it will be a contest to design and build structures 

that can support a horizontal load. What they learn in this unit can be 

applied in the contest. Let them know there will be clearly defined 

parameters and all groups will have an equal opportunity to succeed. 

Label the structures with SET names and put them aside for the 

contest at the end of this unit. V

AGU / FEMA 230 S EISMIC S LEUTHS
AGU / FEMA 231 S EISMIC S LEUTHS
MASTER PAGE Teacher Background Reading 

Building Engineering 

4.1a

During an earthquake, a marked spot on the Earth might be seen to move erratically, tracing out a random path 

resembling that of a wandering insect. “Ground motion” is a literal description, since the ground moves (generally 

for a distance measured only in centimeters) relative to its starting point. The ground motion that is important in 

determining the forces on a building is acceleration. As the seismic waves move through the ground, the ground 

moves back and forth. Acceleration is the rate at which ground movement changes its speed. 

Two other unit measures are directly related to acceleration. Velocity, measured in centimeters per second, refers 

to the rate of the motion at a given instant. Displacement, measured in centimeters, refers to the distance an object 

is moved from its resting position. If you move your hand back and forth rapidly in front of your face, it might 

experience a displacement of 20 to 30 centimeters in one second and its acceleration and velocity may be quite 

high, but no damage will be done because the mass of your hand is low. In a building with a mass in the thousands 

of metric tons, tremendous forces are required to produce the same motion. These forces are transmitted 

throughout the structure, so if the movement repeats for some minutes the building may shake to pieces. 

To overcome the effects of these forces, engineers rely on a small number of components that can be combined to 

form a complete load path. In the vertical plane, three kinds of structural systems are used to resist lateral forces: 

shear walls, braced frames, and moment-resistant or rigid frames. In the horizontal plane, diaphragms (generally 

formed by the floor and roof planes of the building) or horizontal trusses are used. Diaphragms are designed to 

receive lateral force between the vertical resistance elements (shear walls or frames). Shear walls are solid walls 

designed to carry the force to the vertical resistance system. In a simple building with shear walls at each end, 

ground motion enters the building and moves the floor diaphragms. This movement is carried by the shear walls 

and transmitted back down through the building to the foundation. Braced frames act in the same manner as shear 

walls, but may not carry as much load depending on their design. Bracing generally takes the form of steel rolled 

sections (I-beams), circular bar sections (rods), or tubes. Rigid frames rely on the capacity of joints to carry loads 

from columns to beams. Because these joints are highly stressed during movement the details of their construction 

are important. As a last-resort strategy, rigid frames use the energy absorption obtained by deformations of the 

structure before it ultimately fails. 

Architecturally, rigid frames offer a certain advantage over shear walls or braced frames because they tend to 

provide structures that are much less obstructed internally than shear wall structures. This allows more freedom in 

the design of accompanying architectural elements, such as openings, exterior walls, partitions, and ceilings, and 

in the placement of building contents, such as furniture and loose equipment. Nevertheless, moment-resistant 

frames require special construction and detailing and therefore, are more expensive than shear walls or braced 

frames. 

Note: Adapted from FEMA 99, October 1990, Non-technical Explanation of the NEHRP Recommended Provisions.

Diaphragm 

Moment Resistant 

Frame 

Shear Walls 

Braced 

Frame 

AGU / FEMA 232 S EISMIC S LEUTHS
4.2 

Structural Reinforcement: 

The Better Building 

RATIONALE 

Students will learn how diagonal braces, shear walls, and rigid 

connections strengthen a structure to carry forces resulting from 

earthquake shaking. 

FOCUS QUESTIONS 

How may the structure of a building be reinforced to make it better 

able to withstand earthquake shaking? 

OBJECTIVES 

Students will: 

1. Recognize some of the structural elements of a building. 

2. Describe how the horizontal and vertical structural elements carry 

the horizontal and vertical loads of a building. 

3. Describe how diagonal braces, shear walls, and rigid 

connections provide paths for the horizontal load resulting from an 

earthquake. 

4. Observe how added structural elements strengthen a model wall to 

withstand shaking. TEACHING CLUES AND CUES

MATERIALS 

For the teacher: Materials for one model wall 

Jumbo craft sticks are 

available at craft and 

hobby stores. They are 

larger than ice cream 

Q Master 4.2a, Building a Model Wall 

Q 21 jumbo craft sticks, about 15 cm x 2 cm x 2 mm thick 

sticks, about the size of tongue 

depressors. 

Q Electric drill with 3/16" bit 

Q Goggles for eye protection 

Q 1 piece of thin wood (about 2 mm thick) 45 cm x 6 cm (about 18 in. 

x 2 in.) 

You may want to build 

this model and the one 

in Lesson 4.3 at the 

same time, and 

introduce them 

Q 1 piece of sturdy wood (2 x 6) for a base, about 45 cm (18 in.) long 

Q 16 machine bolts, 10 x 24, about 2 cm long (.75 in.) 

Q 16 machine screw nuts, 10 x 24 

Q 32 washers, #8 

both in the same class period. This 

would allow two groups to be actively 

engaged with the models of the 

same time. 

AGU / FEMA 233 S EISMIC S LEUTHS
Q7 small wood screws VOCABULARY 

reinforcing elements for one wall 

Q2 pieces of string, each approximately 25 cm (10 in.) long 

Braces or Bracing: 

structural elements built 

into a wall to add 

Q1 piece of thin wood (about as thick as the craft sticks) 20 cm x 2 cm strength. These may be 

(about 8 in. x 1 in.) 

Q1 piece of lightweight cardboard, about 15 cm x 15 cm (a little less 

than 6 in. square) 

Q8 small paper clamps to fasten wood and cardboard 

for each small group

QOne set of the above supplies if they are each building a model wall 

QOne copy of Master 4.2b, Load Paths Worksheet 

QPens and pencils 

PROCEDURE 

Teacher Preparation 

Assemble the model wall, following the diagram on Master 4.2a, 

Building a Model Wall, and try it out before class. Be sure the bolts 

are just tight enough to hold the structure upright when no force is 

applied. 

A. Introduction 

Tell students that this lesson is designed to demonstrate how the 

structural elements of a wall carry forces. The activity deals with three 

structural elements that carry the lateral shear forces caused by ground 

shaking during an earthquake: diagonal bracing, shear walls, and rigid 

connections. It is designed around an apparatus called the model wall. 

Remind the students that this is a model, designed to demonstrate only 

certain characteristics of real walls. 

B. Lesson Development 

1. Show students the model and tell them that it represents part of the 

frame of a building. Describe the components of the wall, and ask 

them, “What holds this wall up?” The answer is in the interaction of 

the vertical and horizontal elements, but try to keep the students 

focused on discovery, since in this activity they will see the 

architectural principles demonstrated. Explain to students that what 

they refer to as weight will be called the force of gravity in this lesson. 

2. Now ask students to predict what would happen if you quickly 

pushed the base of the wall, simulating an earthquake. Remind them 

that an earthquake may cause ground shaking in many directions, but 

for now we are modeling shaking in one direction only. 

3. Divide the class into the same seismic engineering teams (SETs) as 

for Lesson 1 and give each group one copy of Master 4.2b, Load Paths 

Worksheet. Invite students to take turns investigating the model’s 

response in their small groups. 

made of various materials and 

connected to the building and each 

other in various ways. Their ability to 

withstand stress depends on the 

characteristics of the materials and 

how they are connected. 

Lead: the sum of vertical forces 

(gravity) and horizontal forces (shear 

forces) acting on the mass of a 

structure. The overall load is further 

broken down into the loads of the 

various parts of the building. 

Different parts of a building are 

designed and constructed to carry 

different loads. 

Lead path: the path a load or force 

takes through the structural 

elements of a building. 

Rigid connections: connections 

that do not permit any motion of the 

structural elements relative to each 

other. 

Shear force: force that acts 

horizontally (laterally) on a wall. 

These forces can be caused by 

earthquakes and by wind, among 

other things. Different parts of a wall 

experience different shear forces. 

Shear walls: walls added to a 

structure to carry horizontal (shear) 

forces. These are usually solid 

elements, and are not necessarily 

designed to carry the structure’s 

vertical load. 

Structural elements or structural 

features: a general term for all the 

essential, non-decorative parts of a 

building that contribute structural 

strength. These include the walls, 

vertical column supports, horizontal 

beams, connectors, and braces. 

AGU / FEMA 234 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

This activity is designed 

as a demonstration or as 

a group activity. If you 

decide to have each 

group build a model wall you will 

need more materials. 

Encourage students to 

choose roles within their 

SETs and later report 

their results by role, with 

the technician reporting the data, the 

engineer describing the calculations, 

the scientist explaining the 

relationships, and the coordinator 

facilitating. 

Students may try both 

pushing the structure 

directly and moving the 

table. Shaking the table 

a. Instruct one student in each group to push at the bottom of the 

model from the lower right or left side. (When pushed just fast 

enough, the model should collapse at the first floor only.) Ask students 

why the other floors didn’t collapse. (The first floor collapsed because 

it was too weak to transfer enough horizontal force to move the upper 

stories. It could not transfer the shaking to the upper stories.) 

b. Direct students’ attention to the load path diagrams on Master 4.2b 

and explain that pushing the base of the building is equivalent to 

applying force horizontally to the upper stories. A force applied 

horizontally to any floor of a building is called the shear force on that 

floor. Shear forces can be caused by the ground shaking of an 

earthquake as well as by high winds. Invite students to carefully apply 

horizontal forces at different points on the model to simulate 

earthquake shaking. (Earthquakes affect buildings at ground level.) 

4. Ask students how they could add structural elements to create a 

path for the load to follow to the ground when strong forces act upon 

the structure. Help the students discover the effect of adding a shear 

wall, diagonal bracing, and rigid connections, using string, cardboard, 

extra wood, and clamps, as in the diagrams on the master. On each of 

the three diagrams provided, have students draw a force arrow (a 

vector) and trace the path the force takes to the ground. 

5. Challenge students to design and build three different arrangements 

of the six structural elements depicted on the worksheet. Each time 

they modify the design they must modify the diagram to show the new 

load path. Check each structure and diagram until you are sure that 

students understand the concepts. When a structure is well reinforced, 

you should be able to push on the upper story and slide the whole 

structure without any of the walls failing. 

6. Either have the groups discuss the questions on the master, with one 

student recording each group’s response, or ask individual students to 

write responses to specific questions. After all the groups finish the 

questions, have a reporter for each SET present its response to one of 

the questions. Allow the class to come to some consensus on their 

responses to that question, then proceed to another group until all the 

questions have been discussed. 

C. Conclusion 

As a closing activity, challenge a volunteer to remove an element (a 

craft stick) that, according to the load path diagram, is not carrying 

any load. Have the student unbolt one end of that element and push the 

reinforced structure to see if it holds. It will, if the load path is correct. 

Finally, help the students connect the behavior of their model walls to 

their mental images of real buildings during an earthquake. Emphasize 

that the back and forth, horizontal component (or shearing) of ground 

shaking is the force most damaging to buildings. Buildings are 

primarily designed to carry the downward pull of 

on which the structure rests would 

simulate the transfer of energy from 

the ground to the building. 

AGU / FEMA 235 S EISMIC S LEUTHS
gravity, but to withstand earthquake shaking they need to be able to 

withstand sideways, or horizontal, pushes and pulls. 

ADAPTATIONS AND EXTENSIONS 

1. Challenge students to find the minimum number of diagonal braces, 

shear walls, or rigid connections that will ensure horizontal stability in 

their models. 

2. Invite students to design, construct, and test other structural 

elements that could make buildings earthquake-resistant, such as 

square rigid connections. Some might try putting wheels or sleds on 

the bottom of their buildings. 

3. If you have some very interested students, you may give them 

access to all your building supplies and challenge them to design and 

construct larger structures. Ask students to consider how they could 

design a building so that the ground shaking does not transfer to the 

building. There are new technologies that allow the ground to move, 

but not the building. One of these is called base isolation. Have 

students research this topic in periodicals. (See Unit Resources.) V

AGU / FEMA 236 S EISMIC S LEUTHS
AGU / FEMA 237 S EISMIC S LEUTHS
4.2a MASTER PAGE Building a Model Wall

1. Stack 21 craft sticks one on top of the other. Wrap a rubber band around the center to hold them together. Using 

a 3/16 in. bit, carefully drill a hole through all the sticks at once, 1 cm from the end of the stack. Drill slowly to 

avoid cracking the wood. 

2. Select the thinner of the two large pieces of wood (45 cm x 6 cm). Drill a 3/16 in. hole 1 cm from one end and 1 

cm from the edge. Measure the distance between the holes drilled in the craft sticks and space three more 3/16 in. 

holes at that distance 1 cm from the edge so that a total of four holes are drilled (see illustration). 

3. Use the small wood screws to mount this piece of wood on the base (the 2 x 6), fastening at the bottom and in 

the center. Leave the pre-drilled holes sticking up far enough above the top to accept the drilled craft sticks.

4. Using the bolts, washers, and nuts, assemble the craft sticks to build a model wall. 

5. Experiment with tightening bolts and washers until they are just tight enough for the wall to stand on its own. 

AGU / FEMA 238 S EISMIC S LEUTHS
AGU / FEMA 239 S EISMIC S LEUTHS
MASTER PAGE Load Paths Worksheet

AGU / FEMA 240 S EISMIC S LEUTHS

4.2b 

Name __________________________________________________________ Date ____________________ 

A. Failing Wall 

Observe and explain how the wall fails when its base is shaken rapidly back and forth, simulating the motion of a 

building hit by S waves during an earthquake. Tighten all the nuts just enough to allow the joints to move. 

Sharply push the base a few centimeters horizontally (right or left). 

1. What part of the wall fails first? ______________________________________________________________ 

2. Imagine how the horizontal force you applied to the base travels to the upper parts of the wall. What caused the 

first structural failure?______________________________________________________________________ 

___________________________________________________________________________________________ 

B. Load Paths with Additional Structural Elements 

1. Pick up the two rigid connections, one shear wall (cardboard), one solid diagonal brace, and two pieces of 

string. Add structural elements to your wall to provide paths for the horizontal forces, or loads, to travel through 

the wall. Study the diagrams below to see how these structural elements provide load paths. 

Use arrows to show the load path on each diagram. 
MASTER PAGE 

2. Put additional structural elements on your wall and 

push the third level. If the elements you added provided 

a load path to the base, the base of the wall should move. 

If they do not, the wall will fail somewhere. When you 

discover a setup that works, diagram it and sketch the 

load paths with arrows. Have your instructor look it over 

before you continue. 

3. Design and build another set of additional structural 

elements. Sketch the load path here and have your 

instructor check it. Be sure each member of the team 

designs a set. The base of the model wall should move 

when lateral force is applied to the top elements. 

4. Design and build a third set of additional structural 

elements. Use as few additional elements as possible. 

Sketch the load path and have your instructor check it. 

Be sure each member of the team designs a set. Test 

your load paths by removing elements not in the path to 

see if the building will stand up to a force. 

AGU / FEMA 241 S EISMIC S LEUTHS
MASTER PAGE 

C. Summary 

1. What is a load path? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

2. Why must additional structural elements be added to a wall before it can carry horizontal forces? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

3. How many additional elements did you need to add? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

4. Why doesn’t the force take some path other than the one you diagrammed? 

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________ 

AGU / FEMA 242 S EISMIC S LEUTHS
AGU / FEMA 243 S EISMIC S LEUTHS
MASTER PAGE Load Paths Worksheet (key)

AGU / FEMA 244 S EISMIC S LEUTHS

4.2b 

A. Failing Wall 

Observe and explain how the wall fails when its base is shaken rapidly back and forth, simulating the motion of a 

building hit by S waves during an earthquake. Tighten all the nuts just enough to allow the joints to move. 

Sharply push the base a few centimeters horizontally (right or left). 

1. What part of the wall fails first? The first floor 

2. Imagine how the horizontal force you applied to the base travels to the upper parts of the wall. What caused the 

first structural failure? The first floor has to carry all the load to the upper stories. It transfers forces to move 

the upper stories. 

B. Load Paths with Additional Structural Elements 

1. Pick up the two rigid connections, one shear wall (cardboard), one solid diagonal brace, and two pieces of 

string. Add structural elements to your wall to provide paths for the horizontal forces, or loads, to travel through 

the wall. Study the diagrams below to see how these structural elements provide load paths. 

Use arrows to show the load path on each diagram. 
MASTER PAGE 

2. Put additional structural elements on your wall and 

push the third level. If the elements you added provided 

a load path to the base, the base of the wall should move. 

If they do not, the wall will fail somewhere. When you 

discover a setup that works, diagram it and sketch the 

load paths with arrows. Have your instructor look it over 

before you continue. 

3. Design and build another set of additional structural 

elements. Sketch the load path here and have your 

instructor check it. Be sure each member of the team 

designs a set. The base of the model wall should move 

when lateral force is applied to the top elements. 

4. Design and build a third set of additional structural 

elements. Use as few additional elements as possible. 

Sketch the load path and have your instructor check it. 

Be sure each member of the team designs a set. Test 

your load paths by removing elements not in the path to 

see if the building will stand up to a force. 

AGU / FEMA 245 S EISMIC S LEUTHS
MASTER PAGE 

C. Summary 

1. What is a load path? 

The path that the load (or force) follows through the structural elements of a building.

2. Why must additional structural elements be added to a wall before it can carry horizontal forces? 

Normally, buildings only have to support vertical force (gravity). When horizontal forces are applied, as in an 

earthquake, additional elements are needed to carry them. 

3. How many additional elements did you need to add? 

Each joint needs only one additional structural element. Only one joint on each floor needs to carry the horizontal 

force, in this model. 

4. Why doesn’t the force take some path other than the one you diagrammed? 

The diagram shows the places that are strong enough to carry the load. If there were more than one place, the 

load (or force) would travel through both. 

AGU / FEMA 246 S EISMIC S LEUTHS
AGU / FEMA 247 S EISMIC S LEUTHS
4.3 

The BOSS Model: 

Building Oscillation Seismic Simulation 

TEACHING CLUES AND CUES

As noted in lesson 4.2, 

you may want to have 

one group of students 

working with this model 

while another is working with the 

model wall.

TEACHING CLUES AND CUES

Since the rods can 

break with rough 

handling, you may want 

to buy one or two extra.

RATIONALE 

During an earthquake, buildings oscillate. If the frequency of this 

oscillation is close to the natural frequency of the building, resonance 

may cause severe damage. The BOSS model allows students to 

observe the phenomenon of resonance. 

FOCUS QUESTIONS 

Why do buildings of different heights respond differently in an 

earthquake? 

OBJECTIVES 

Students will: 

1. Predict how a structure will react to vibrations (oscillations) of 

different frequencies. 

2. Perform an experiment to establish the relationship between the 

height of a structure and its natural frequency. 

3. Describe the phenomenon of resonance. 

MATERIALS

for one BOSS Model 

Q Master 4.3a, BOSS Model Assembly 

Q 4 pieces of wood, 1 x 4, each 15 cm (6 in.) long 

Q 1 piece of wood, 2 x 4, for a base, about 45 cm (18 in.) long 

Q 2 threaded rods, 10 x 24, each 96 cm (36 in.) long 

Q 2 threaded rods, 10 x 24, each 61 cm (2 ft.) long 

Q Goggles for eye protection 

Q Hacksaw or power saw with metal-cutting blade 

Q Electric drill or hand drill with 1⁄4-in. and 3⁄4-in. wood bore bits 

Q Hammer 

Q 8 wing nuts, 10 x 24 

Q 8 tee nuts, 10 x 24 

AGU / FEMA 248 S EISMIC S LEUTHS
Q 8 washers, #8 VOCABULARY 

Q A wide permanent marker in any color that will contrast with the 

wood 

Q Poster paints: red, green, blue, black, and white, and 5 brushes 

Amplitude: a measurement of the energy of a 

wave. Amplitude is the 

displacement of the 

(optional) 

for each small group 

Q One copy of Master 4.3b, BOSS Worksheet 

Q Pencils or pens 

Q Stopwatch 

Q Meter stick 

PROCEDURE 

Teacher Preparation 

Build the BOSS model by following the directions on Master 4.3a. 

Practice with your model until you’ve got a feel for each frequency 

and you can get any of the rod assemblies to resonate. One technique 

is to use a firm push first, then watch the number you want and wiggle 

the base very lightly at its natural frequency to get resonance. 

A. Introduction 

Find out what students already know about the concepts of amplitude, 

frequency, and resonance. If they are not familiar with these terms, 

introduce them by building on what students already know from other 

areas. They may know, for example, that resonance and frequency are 

used in describing the tone of musical instruments and the quality of 

sound produced by different recording techniques and players. The 

phenomenon of resonance also accounts for laser light and for the 

color of the sky. 

B. Lesson Development 

1. Direct students’ attention to the BOSS model, and explain its name. 

Ask the students to predict which numbered rod assembly will 

oscillate the most when you wiggle the base. Have them hold up 1, 2, 

3, or 4 fingers to indicate their prediction. (They will probably say 

number 1 because it is the tallest.) 

2. Oscillate the BOSS model so that some rod assembly resonates 

other than the one most students predicted. This will baffle the 

students, so let them predict again. Again make the rod resonate for an 

assembly they did not predict. Finish this demonstration after several 

tries by making the rod resonate for the assembly most of the students 

did predict, so that they get it right. Invite discussion. 

3. Relate the blocks and rods to buildings of various heights in an 

earthquake. Ask students if they think buildings would oscillate like 

this in an earthquake. (They always do, and in some earthquakes the 

effect is especially pronounced. In the 1985 Mexico City earthquake, 

the ground shaking resonated with the natural frequencies of 8-to-10- 

medium from zero or the height of a 

wave crest or trough from a zero 

point. (In this activity it’s how far to 

the side the block moves.) 

Frequency: the rate at which a 

motion repeats, or oscillates. The 

frequency of a motion is directly 

related to the energy of oscillation. In 

this context, frequency is the number 

of oscillations in an earthquake wave 

that occur each second. In 

earthquake engineering, frequency 

is the rate at which the top of a 

building sways. 

Hertz (Hz): the unit of measurement 

for frequency, as recorded in cycles 

per second. When these rates are 

very large, the prefixes kilo or mega

are used. A kilohertz (kHz) is a 

frequency of 1,000 cycles per 

second and a megahertz (MHz) is a 

frequency of 1,000,000 cycles per 

second. 

Oscillation or vibration: the 

repeating motion of a wave or a 

material—one back and forth 

movement. Earthquakes cause 

seismic waves that produce 

oscillations, or vibrations, in 

materials with many different 

frequencies. Every object has a 

natural rate of vibration that 

scientists call its natural frequency. 

The natural frequency of a building 

depends on its physical 

characteristics, including the design 

and the building materials. 

Resonance: an increase in the 

amplitude (in this case, the distance 

the top of a building moves from its 

rest position) of a physical system 

(such as a building) that occurs 

when the frequency of the applied 

oscillatory force (such as earthquake 

shaking) is close to the natural 

frequency of the system. 

AGU / FEMA 249 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

You may choose to have 

students build models in 

class. In that case, you 

will need to make student copies of Master 4.3a, and 

assembly will become step 1 under 

Lesson Development. You will also 

need more materials. 

Instruct students to start 

the stopwatch as a 

numbered block reaches 

its maximum swing and 

story buildings. The effect was severe damage to medium-height 

buildings that had the same frequency as the ground shaking and 

resonated with it. Higher and lower buildings were hardly damaged.) 

Use the BOSS model as a visual aid when describing this event. You 

may also want to draw attention to the photos or books you used in 

Lesson 1 of this unit. 

4. Divide students into seismic engineering teams (SETs) and 

distribute one copy of Master 4.3b, BOSS Worksheet, to each group. 

Tell students that they will take turns performing an experiment with 

the model, recording their data, and providing the answers asked for 

on the data sheet. Give these directions: 

a. Hold the base stationary, pull the wooden number 1 out several 

centimeters to the side, and release it. As the rod oscillates, use a 

stopwatch to measure the time for 10 oscillations. Record this number. 

b. Practice until you can get almost the same swing each time, then 

repeat the measurement four times. Calculate the average of these four 

times. Now calculate the natural frequency of the number by dividing 

10 cycles by the average time. Record it. Repeat this procedure for the 

other three numbers. 

c. Measure the height of each assembly from the base to the top, and 

record it. 

d. Plot height versus natural frequency on the graph provided. 

(Students should come up with a hyperbola, a curve representing an 

inverse relationship in which, as the height of the structure increases, 

its natural frequency decreases.) 

e. Ask the class: From what you have learned, do the earthquakes with 

the highest numbers on the Richter Scale always do the most damage? 

(Students should already know that the amount of damage has to do 

with population density and other factors, but now they will be aware 

of something new. To illustrate the relationship of frequency and 

resonance, use the example of someone pushing a child in a swing. 

The person pushes a little at a time, over time, and soon the swing 

goes very high without a big push. Each small push is at the right 

frequency. Similarly, a building may vibrate with a great amplitude 

without big earthquake vibrations because the smaller vibrations came 

at that structure’s natural frequency.) 

5. Ask the SETs to share and discuss their results. Again point out the 

connection between the experimental results and the way real 

buildings resonate. Other things being equal, taller buildings have 

lower natural frequencies than short buildings. 

C. Conclusion 

Review the terms and concepts introduced in this lesson. Explain that 

seismic waves caused by earthquakes produce oscillations, or 

vibrations, in materials with many different frequencies. Every object 

has a natural rate of vibration that scientists call its natural frequency. 

The natural frequency of a building depends on its physical 

start counting with zero. Often 

students will start counting with one 

when they start the stopwatch and 

end up with only nine swings. 

AGU / FEMA 250 S EISMIC S LEUTHS
cal characteristics, including the design and the building materials. 

Resonance is a buildup of amplitude in a physical system that occurs 

when the frequency of an applied oscillatory force is close to the 

natural frequency of the system. In the case of an earthquake, the 

ground shaking may be at the same frequency as the natural frequency 

of a building. Each vibration in the ground may come at or 

dangerously close to the natural frequency of the structure. 

Ask the class to hypothesize what would happen when buildings of 

two different heights, standing next to each other, resonate from an 

earthquake. Wiggle the BOSS model so that assemblies 2 and 3 

vibrate greatly, and let students see how buildings hammer together 

during powerful earthquakes. If you have some images of this effect 

from actual earthquakes, show them now. 

Entice students to further investigation by leaving them with the 

question: “How could you add structural elements to reduce resonance 

in a building?” 

ADAPTATIONS AND EXTENSIONS 

1. Tell students that one way to protect a building from resonating 

with an earthquake is to isolate its foundation, or base, from the 

ground with devices much like wheels. This technique is called base 

isolation. Structural engineers are now developing the technology to 

place buildings on devices that absorb energy, so that ground shaking 

is not directly transferred to the building. 

Invite students to add standard small wheels from a 

hardware store to their models as an illustration of one of 

the many base isolation technologies, or add wheels to 

your own BOSS model, then shake the table. Better yet, 

place the model in a low box or tray and shake it. Then 

take out the model, fill the box with marbles or BBs, and 

replace the model on this base. Now shake the box. 

Challenge students to come up with other base isolation 

techniques. 

2. If any of your students have studied harmonic motion in 

a physical science or physics class, challenge them to 

explain how the BOSS model is an example of an inverted 

pendulum. 

3. To help students connect the numbered rod assemblies 

to actual buildings, make paper sleeves and decorate them 

to resemble buildings in your area. At some point in the 

lesson, slide the sleeves over the rod assemblies to show 

how buildings can collide, or hammer against each other, 

during an earthquake. V

AGU / FEMA 251 S EISMIC S LEUTHS
4.3a MASTER PAGE BOSS Model Assembly

1. Cut one of the meter-long threaded rods down 

to 75 cm, leaving the other full length. 

2. Cut one of the 61-cm threaded rods down to 45 

cm, leaving the other full length. 

3. Drill a .63-cm (1/4 in.) hole through the center 

of one of the short sides in each of the 15-cm 

pieces of wood. (See assembly diagram.) 

4. Hammer a tee nut into the hole on one end of 

each 15-cm piece. 

5. Countersink four 3/4-in. holes about 1/8 in. 

deep into the 45-cm 2 x 4 at 12-cm intervals, as 

marked on the diagram. (This will allow you to 

countersink the nuts so they don’t scratch the 

surface where the model rests.) 

6. Drill four 1/4-in. holes in the 45-cm 2 x 4 in the 

countersunk holes. 

7. Hammer a tee nut into each countersunk hole. 

Turn the board over so the tee nuts are on the 

bottom. 

8. Assemble the rods and the base as shown on the 

diagram. 

9. Use the permanent marker to label the 15-cm 1 

x 4 blocks in order, 1, 2, 3, and 4. 

Optional: Paint the four 15-cm pieces of wood 

in four different colors. When they are dry, 

number them, with the white paint. 

AGU / FEMA 252 S EISMIC S LEUTHS
AGU / FEMA 253 S EISMIC S LEUTHS
4.3b MASTER PAGE BOSS Worksheet

Name ___________________________________________________________ Date _____________________ 

Cooperative Group ____________________________ Scientist __________________________________ 

Coordinator ____________________________ Technician __________________________________ 

Engineer ____________________________ 

Record oscillation times in the data table below in the appropriate place for each rod assembly. These times are 

measured in seconds per 10 cycles. Repeat the measurement four times to minimize human error, then record. 

Caution: Start the stopwatch as a numbered block reaches its maximum swing and start counting with zero, otherwise you 

will end timing only nine swings. Practice this until your times for 10 oscillations are fairly close to each other. 

Calculate the average time for each oscillation by adding four measurements and dividing by four. Record. 

Calculate the natural frequency. Divide 10 cycles by the average time (do not simply move the decimal point). 

Frequency is measured in hertz, or cycles per second. Record. 

A. Data Table: Oscillation Times 

Rod Assembly Oscillation Time (sec/10 cycles) 

Trial 1 Trial 2 Trial 3 Trial 4 

Avg. Oscillation Times 

(sec/10 cycles) 

Natural Frequency Hertz 

(cycles/sec) 

#1

#2

#3

#4

1. How much variation do you notice among the four trials? __________________________________________ 

2. What relationship do you notice, if any, between the height of the rods and their natural frequencies? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

B. Heights of the Rod Assemblies 

1. Measure the height of each rod assembly from the base to the top of the block and record it. 

Rod Assembly Height (cm) 

#1 

#2 

#3 

#4 

2. What is the approximate difference in height between #1 and #2, #2 and #3, and so on? 

___________________________________________________________________________________________ 

AGU / FEMA 254 S EISMIC S LEUTHS
4.3b MASTER PAGE BOSS Worksheet

3. Plot the height versus the natural frequency of each 

rod assembly on the graph provided. You should have 

four data points. Connect the points with the best fitting 

straight or curved line you can. 

4. What kind of line did you get from your data? 

_____________________________________________ 

5. As the height of the rod assemblies gets larger, what 

happens to their natural frequency? 

_____________________________________________

_____________________________________________

_____________________________________________

_____________________________________________ 

C. Summary 

1. What variable is manipulated in this experiment? (How do the four rod assemblies differ from each other?) 

___________________________________________________________________________________________ 

2. What is the responding variable in this experiment? (What did you measure?) 

___________________________________________________________________________________________ 

3. What does oscillate, or vibrate, mean? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

4. Define frequency. 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

5. Why does only one rod assembly oscillate greatly (or resonate) when you wiggle the base? 

___________________________________________________________________________________________ 

6. What is resonance? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

7. How are the rod assemblies like buildings? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

8. (extra credit) How can a building be protected from resonating with seismic vibrations? 

___________________________________________________________________________________________ 

___________________________________________________________________________________________ 

AGU / FEMA 255 S EISMIC S LEUTHS
4.3b MASTER PAGE BOSS Worksheet (key)

Record oscillation times in the data table below in the appropriate place for each rod assembly. These times are 

measured in seconds per 10 cycles. Repeat the measurement four times to minimize human error, then record. 

Caution; Start the stopwatch as a numbered block reaches its maximum swing and start counting with zero, otherwise you 

will end timing only nine swings. Practice this until your times for 10 oscillations are fairly close to each other. 

Calculate the average time for each oscillation by adding four measurements and dividing by four. Record. 

Calculate the natural frequency. Divide 10 cycles by the average time (do not simply move the decimal point). 

Frequency is measured in hertz, or cycles per second. Record. 

A. Data Table: Oscillation Times 

Rod Assembly Oscillation Time (sec/10 cycles) 

Trial 1 Trial 2 Trial 3 Trial 4 

Avg. Oscillation Times 

(sec/10 cycles) 

Natural Frequency Hertz 

(cycles/sec) 

#1 11 0.9 

#2 6.7 1.5 

#3 5 2.0 

#4 3 3.3 

1. How much variation do you notice among the four trials? Oscillation times vary by less than 10 percent. 

2. What relationship do you notice, if any, between the height of the rods and their natural frequencies? 

The shorter the rod, the higher the natural frequency. The taller the rod, the lower the natural frequency. 

B. Heights of the Rod Assemblies 

1. Measure the height of each rod assembly from the base to the top of the block and record it. 

Rod Assembly Height (cm) 

#1 89 

#2 73 

#3 57 

#4 42 

2. What is the approximate difference in height between #1 and #2, #2 and #3, and so on? 

Approximately 15 cm, the height of the wooden rectangle at the top of each rod assembly. 

Note: Data will vary with specific BOSS model and student. Values in the tables are to assist the teacher and are not to be used in 

evaluating students. 

AGU / FEMA 256 S EISMIC S LEUTHS
MASTER PAGE 

3. Plot the height versus the natural frequency of each rod 

assembly on the graph provided. You should have four data 

points. Connect the points with the best fitting straight or 

curved line you can. 

4. What kind of line did you get from your data? 

 A symmetrical curve, or hyperbolic curve. 

5. As the height of the rod assemblies gets larger, what 

happens to their natural frequency? 

As the height increases, the natural frequency decreases. 

C. Summary 

1. What variable is manipulated in this experiment? (How do the four rod assemblies differ from each other?) 

 The height of the rods varies. 

2. What is the responding variable in this experiment? (What did you measure?) 

 The natural frequency of each rod assembly. 

3. What does oscillate, or vibrate, mean? 

 Wiggle back and forth, or move repetitively. 

4. Define frequency. 

 In this case, the frequency is the number of oscillations per second. 

5. Why does only one rod assembly oscillate greatly (or resonate) when you wiggle the base? 

 The vibration only adds up in one rod, or only one rod will resonate at each shaking. 

 You have found the rod’s natural frequency. 

6. What is resonance? 

 When a structure is vibrated at its natural frequency, the vibrations add up. This is called resonance. 

7. How are the rod assemblies like buildings? 

 They have mass that is attached to the base by a structure. 

 Or—They have fixed bases attached to freely oscillating tops by tall, stiff structures. 

8. (extra credit) How can a building be protected from resonating with seismic vibrations? 

 Dampen the building’s vibration with something like the shock absorbers on a car. 

 Isolate the base of the building from the ground. (Accept other reasonable suggestions.) 

AGU / FEMA 257 S EISMIC S LEUTHS
4.4 

 in a Box

VOCABULARY

Retrofitting: making 

changes to a completed 

structure to meet needs 

that were not considered 

RATIONALE 

In cooperative SETs (seismic engineering teams), students win 

construct an inexpensive shake table for testing structures they have 

built. 

FOCUS QUESTIONS 

How do earthquake engineers use shake tables to model the effects of 

an earthquake on buildings, bridges, and other structures? 

OBJECTIVES 

Students will: 

1. Construct a model of a shake table. 

2. Design structures of various types and use the shake table to test 

their seismic survivability. 

3. Analyze the failures of their design models and suggest ways to 

reduce damage. 

at the time it was built; in this case, 

to make it better able to withstand an 

earthquake. 

Variable: in a scientific experiment, 

the one element that is altered to test 

the effect on the rest of the system.

MATERIALS TEACHING CLUES AND CUES 

for each small group 

Q One copy of Master 4.4a, Shake Table Directions 

Q One piece of cardboard approx. 28 cm by 38 cm (11 in. x 15 in.) 

Use corrugated 

cardboard for greatest 

strength.

Q Wide packaging tape 

Q Hole-punching tool 

Q Metric ruler 

Q One cardboard box with flaps removed, approx. 30 cm by 40 cm by 

20 cm (12 in. x 16 in. by 8 in. deep) 

Q Dark blue or black marker 

The size of the box may 

vary, as long as the size 

of the cardboard varies 

with it. 

Q Phillips screwdriver 

Q 3 strands of packaging string, one about 30 cm long (12 in.) and 

two about 60 cm long (24 in.) 

Q 4 heavy-duty rubber bands 

AGU / FEMA 258 S EISMIC S LEUTHS
QPaper clips TEACHING CLUES AND CUES 

QTwo craft or ice cream sticks 

QVCR and videotape (optional; see adaptations) 

A gallon plastic jug with 

the top cut off makes an 

excellent storage 

container for the dry 

materials. 

QA variety of materials for building structures, such as sugar cubes, 

ice cream sticks, small interlocking blocks, peanut butter (for 

mortar), dry spaghetti, straws, pipe cleaners, paper clips, cardboard, 

string, aluminum foil, and Styrofoam 

PROCEDURE 

Teacher Preparation 

1. Several days before you plan to do this activity, ask students to 

bring cardboard boxes and building materials from home. Suggest the 

items at the end of the materials list; students may think of others on 

their own. Gather the remaining materials, including extra odds and 

ends for students who forget, and arrange them in a convenient place. 

2. Following the directions on Master 4.4a, build one shake table to 

use as a demonstration model. 

A. Introduction 

Tell the class that earthquake engineers use devices called shake tables 

to model the effects of an earthquake on buildings, bridges, and other 

structures. In this lesson, students will build simple shake tables and 

use them to test their own model structures. 

TEACHING CLUES AND CUES 

Give students plenty of 

time to complete this 

step. 

Use a paper clip to 

anchor one end of the 

rubber band, and a 

second paper clip as a 

B. Lesson Development 

1. Direct students to gather into SETs as for the other lessons in this 

unit. 

2. Distribute one copy of Master 4.4a, Shake Table Directions, to 

each team. Invite students to assemble their materials and build the 

shake tables. Offer assistance only as needed. 

3. When all the groups have completed their tables, list these 10 

variables on the chalkboard or poster paper: 

Q shape of structure 

Q height of structure 

Q construction materials 

Q shape of structural elements (triangle or rectangle) 

needle to thread the rubber bands 

through the holes. 

Q nonstructural exterior features (overhanging moldings, heavy 

decorative panels)

Q foundation strength 

Q siting (type of soil structure is built on) 

Q duration (how long the earthquake lasts) 

Q intensity (how intense earth shaking is at the building’s site) 

Q frequency 

AGU / FEMA 259 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

Work with the class to 

standardize the 

operating procedure as 

much as possible. Have 

Ask each SET to select three variables from the list and design one 

model to test their impact, singly or in combination, when the 

structures are placed on the shake table. Remind students to include 

lifelines like bridges and electrical wires with their supports, as well as 

houses and other buildings. 

4. Have students in each SET take turns operating the model, while the 

other members of the team record their observations. 

5. Assign each SET to write a brief report, based on the notes from 

testing, that includes 

Q a summary of the team’s observations 

Q reasons why their design suffered and/or resisted damage 

Q suggestions for making each design more quake resistant 

Q suggestions for retrofitting structures, where applicable 

Q diagrams illustrating all of the above 

them practice putting the string in 

one short jerk, and be sure that 

everyone uses approximately the 

some kind of pull. This will allow you 

to compare the work of various 

groups, and make students’ results 

reproducible. 

C. Conclusion 

Invite one representative from each SET to share the highlights of the 

team’s report. When all the reports have been given and discussed, 

conduct open discussion around one or more of these topics: 

Q How do municipalities develop building codes for earthquakeprone areas?

Q Should schools, senior citizen homes, hospitals, fire stations, police 

stations, and other essential facilities be forced to follow tougher 

earthquake codes? Why? Why might governments encounter 

resistance to these standards? (because of the expense involved, 

among other factors) 

Q Is it possible to develop a classification system for types of 

structures and their reaction to an earthquake? What factors would 

such a system include? 

ADAPTATIONS AND EXTENSIONS 

1. If a VCR is available, have each team record its experiments and 

play them back in slow motion for detailed observation. Try to 

determine the frequency of each structure. 

2. Challenge students to develop improved shake table designs, based 

on this model and their own ideas. Some students may choose to 

develop a shake table and test their best model structures as a science 

fair project. 

3. Interested students might design a lifelines model that effectively 

illustrates the impact of a damaging earthquake upon buried pipe, 

sewer, gas, oil, water, and electrical lines. 

4. As a research project, students might assess, in dollars and cents, 

the, loss of property that has occurred in specific earthquakes because 

of structural and nonstructural failures, then research the cost and 

availability of earthquake insurance in: 

AGU / FEMA 260 S EISMIC S LEUTHS
Q your respective area 

Q New Madrid, Missouri 

Q San Francisco, California 

Q Boston, Massachusetts 

Q Anchorage, Alaska 

Q Kona, Hawaii 

Q Charleston, South Carolina 

Q Syracuse, New York 

Q other geographic areas of interest 

Do the insurance policies have the same premiums and regulations in 

all of the above geographic areas? Explain. Is all earthquake damage 

covered by insurance? Why or why not? V

Note: This activity was inspired by one developed by Katharyn E. K. Ross, (1993), 

“Using Shake Tables in The Pre-College Classroom: Making The Impact of 

Earthquakes Come Alive,” Proceedings: 1993 National Earthquake Conference, 

Central United States Earthquake Consortium, Memphis, TN, Vol. 1, pp. 423-429. 

AGU / FEMA 261 S EISMIC S LEUTHS
4.4a MASTER PAGE Shake Table Directions 

A. The Shake Platform 

1. Reinforce the cardboard by covering all four edges with packaging tape or doubling the thickness. 

2. Center a hole in each corner of the piece of cardboard 2.5 cm (1 in.) from both edges.

3. Locate the center of the long side of the cardboard by measuring halfway between the two holes you made at 

the comers in step 2. Punch a hole at that center point, one inch from the outside edge on one side. Repeat for the 

two short sides. Punch a hole in the exact center of the cardboard. You now have a total of eight holes in the 

platform. 

B. The Shoe Box 

1. On one of the two ends of the box that is 30 cm across 

(one of the shorter sides), measure 6 cm (about 2.5 in.) 

down from the top and mark this point. Draw a straight 

line through the point all the way across this end of the 

box. Measure 4 cm (about 1.5 in.) in from the right edge 

along the line and mark this point. Punch a hole there 

with the Phillips screwdriver. Punch another hole in the 

center of the box bottom. 

Note: Size of platform should be 5-8 cm 

less than box dimensions to allow room 

for shaking. Dimensions will vary with 

box size.

AGU / FEMA 262 S EISMIC S LEUTHS
MASTER PAGE 

2. Measure 4 cm from the left edge on the same line and punch another hole, as illustrated. Punch two more holes 

4 cm beneath the top two. Then, measure to find the point at the center of a four holes on this side. Mark that point 

and punch one small hole. 

3. Follow the same procedure on the opposite end of the box. 

C. Putting It Together 

1. Tie the 30-cm length of string securely to the center of a craft or ice cream stick. Pull the free end of the string 

down through the center hole on the top of the shaking platform. The stick will keep the string from pulling 

through the hole. Leave enough string to pull through to the outside of the box.

2. Tie the two longer pieces to the center of a craft or ice cream stick. Pull them down 

through the center hole on the long side of the platform, then out through the center 

hole on the short sides of the platform. Reinforce the stick with tape if desired. When 

the table is fully assembled, you will pull on these strings to shake the platform. 

3. While one student holds the platform in place inside the box, parallel to the floor, 

another student will thread a rubber band through the right upper hole in the A end of 

the box and the right outer hole of the shake platform, then out the lower hole in the 

box. 

Use a paper clip to hold the rubber band in place. Do the same thing with the opposite holes on End A. Then, turn 

the box and repeat with End B. Pull the loose ends of both strings out through the center holes. 

AGU / FEMA 263 S EISMIC S LEUTHS
The Building Challenge

AGU / FEMA 264 S EISMIC S LEUTHS

4.5 

VOCABULARY

Braces, or Bracing: 

structural elements built 

into a wall to add 

strength. These may be 

RATIONALE 

A model structure can demonstrate the effects of diagonal bracing, 

shear walls, and rigid connections on a building’s ability to carry loads 

similar to those created by an earthquake. 

FOCUS QUESTIONS 

How can you design and build a model structure to carry vertical and 

horizontal loads? 

OBJECTIVES 

Students will: 

1. Use diagonal bracing, shear walls, and rigid connections to provide 

load paths in a structure. 

2. Design and build a structure that will carry both vertical and 

horizontal loads caused by ground shaking. 

3. Measure the magnitude of the shear force or horizontal load a 

structure can carry. 

MATERIALS 

for each small group (SET) 

Q Structures from Lesson 4.1 

Q 20 Styrofoam sticks, 2.5 cm x 2.5 cm x 15 cm, precut in preparation 

for lesson 4.1 

Q 3 pieces of string, each 30 cm long 

Q 10 paper clips 

Q 20 toothpicks 

Q Any materials from Lesson 4.4 that students want to use 

Q 1 square of tag board, 17.5 cm x 17.5 cm (about 7 in. square), to act 

as a shear wall 

Q 2 right triangles of tag board, cut from a 6-cm square, to act as rigid 

connections 

made of various materials and 

connected to the building and each 

other in various ways. Their ability to 

withstand stress depends on the 

characteristics of the materials and 

how they are connected. 

Diagonal braces: structural 

elements that connect diagonal 

joints. These braces may be made of 

solid materials or flexible materials. 

How they function depends on what 

they are made of and how they are 

connected. 

Load: the sum of vertical forces 

(gravity) and horizontal forces (shear 

forces) acting on the mass of a 

structure. The overall load is further 

broken down into the loads of the 

various parts of the building. 

Different parts of a building are 

designed and constructed to carry 

different loads. 

Rigid connections: connections 

that do not permit any motion of the 

structural elements relative to each 

other. 

Shaking: in this lesson, rapid 

horizontal vibration of the base of the 

model, simulating an earthquake. In 

an actual earthquake, of course, 

shaking occurs in many directions. 
Q1 square of cardboard, 30 cm x 30 cm or larger (about 1 ft square) VOCABULARY 

to serve as the base 

QOne copy of Master 4.5a, Building Challenge Design and Analysis 

Sheet 

Shear force: force that 

acts horizontally 

(laterally) on a wall. 

These forces can be 

for the teacher

QHot glue and glue gun (to be used by one group at a time, under 

direct supervision) 

QShaking table from Lesson 4.4 

QA dog leash or other nylon strap about 2.5 cm wide and at least 60 

cm long 

QSeveral meters of string 

QA small pulley 

QWeights, either a kilogram mass set or a small basket and pennies 

QMaster 4.5b, Certificate of Achievement 

QSlides or videos from the unit resource lists (optional) 

PROCEDURE 

Teacher Preparation 

1. If you want to make the testing of student models a special event, 

make plans now. See Adaptation 1. If you have arranged to involve 

guest experts, remind them of the date. 

2. Prepare the testing setup. Collect all the materials and have them 

ready to distribute. 

A. Introduction 

Briefly review with students what they have experienced so far in this 

series of activities. Especially promote discussion of the ideas 

developed in Lesson 4.2. Be careful to leave the applications of those 

ideas very open, to avoid giving students the impression that there is 

only one right way to design a structure. 

caused by earthquakes and by wind, 

among other things. Different parts 

of a wall experience different shear 

forces. 

Shear walls: walls added to a 

structure to carry horizontal shear 

forces. These are usually solid 

elements, and are not necessarily 

designed to carry the structure’s 

vertical load. 

Structural elements or Structural 

features: a general term for all the 

essential, non-decorative parts of a 

building that contribute structural 

strength. These include the walls, 

vertical column supports, horizontal 

beams, connects, and braces. 

B. Lesson Development 

1. Direct students to gather in the seismic engineering teams (SETs) 

they formed in Lesson 1 of this unit. You may want to have students 

choose roles within the teams, like coordinator, engineer, and 

technician, to organize the effort and to assign accountability for 

timing, design, construction, and describing the performance of the 

structure. 

2. Return to each team the structure members built in Lesson 1. 

Challenge the teams to design and build a new structure that will be 

tested in a controlled environment. Hand out the worksheets and give 

students time to design their structures before they receive their 

materials. Circulate among the groups and approve step 1 and step 2 of

the designs as they are completed. 

3. Demonstrate the procedure you will use to test the structures. 

AGU / FEMA 265 S EISMIC S LEUTHS
TEACHING CLUES AND CUES

This design may take a 

full class period. 

Trace the structure’s 

outline with a pencil or 

pen, put glue on the 

cardboard along the 

outline, and press the structure down 

firmly. The hot glue may melt the 

Styrofoam if applied directly. Warn 

students not to drip the glue on their 

hands. 

This activity will 

generate considerable 

excitement. Let students 

enjoy it, but maintain 

order to be sure 

4. Hand out all the materials except the glue guns, being certain every 

team receives the same set of materials. Allow some time for 

experimentation with the materials before students finalize their load 

path diagrams. Be sure students in each group have drawn force 

arrows on their design (step 3) to predict how they think earthquake 

shear forces will travel through (or load) their structure. 

5. Establish how much time the SETs will have to build their 

structures, either by setting a uniform time for all or by inviting each 

SET to commit to a time limit and appoint one member of the team to 

keep track of time. (This could simulate the process of bidding on 

contracts, and add an extra element of competition.) Then give the 

signal to begin. 

6. When building is finished, use one of the models from Lesson 1 to 

demonstrate fastening the structures to the center of the cardboard 

bases with hot glue. Have groups bring their models to the materials 

table to use the glue gun so you can supervise the process. 

C. Conclusion 

As the teams in turn bring their models to the front of the room for 

testing, test every model two ways—with the shaking table and by 

applying weight. Tell students they are not allowed to touch their 

structures during testing. 

Ask two students from each team to hold the cardboard base down 

while you test their model with weights. Use the strap to add horizontal stress in any increment the group specifies. Call out the weights 

and keep a record on the board of the greatest weight each structure 

held. Award the certificate of achievement to the teams whose 

structures withstand the shaking table and hold the greatest stress 

before breaking. (This may be one team or two.) 

Ask one member of each team to describe how their structure behaved 

in testing. Where did it fail? Why? 

Close by connecting the images students have of earthquake damage to 

buildings with how their structures were damaged by the artificial 

earthquakes of this event. Slides or videos would help to make this real. 

ADAPTATIONS AND EXTENSIONS 

1. After you have done this with one class and feel comfortable with 

it, you may want to make the testing of student models a special event. 

Create some award for the structure that carries the greatest shear 

force. Invite your local newspaper reporters and school board 

members, arrange to use the auditorium, tape appropriate music, and 

plan refreshments. Take videos of the structure tests. Ask the principal 

to apply the weights and judge the event, and invite local emergency 

services officials to attend. 

2. The experiences and materials the students developed in this unit 

make a fine portfolio. Invite students to include drawings of their 

designs and evaluate their learning by describing how they would build 

a structure next time or how they would retrofit their structure. V

all students have fun and are treated 

equally. 

AGU / FEMA 266 S EISMIC S LEUTHS
AGU / FEMA 267 S EISMIC S LEUTHS
MASTER PAGE Building Challenge Design 

and Analysis Sheet 4.5a 

Name ___________________________________________________________ Date _____________________ 

Cooperative Group Scientist 

Coordinator Technician 

Engineer 

1. Sketch a design for your structure in the space provided below. 

2. Use this space to show what it will look like from the front. 

3. Use this space to show what it will look like from the side. 

4. Do a load path diagram for your structure on the back of this page. 

In all your drawings, show clearly how the joints will be made. 

Get your instructor’s approval for all four drawings before actually building your structure. 

AGU / FEMA 268 S EISMIC S LEUTHS
AGU / FEMA 269 S EISMIC S LEUTHS
4.5b MASTER PAGE Certificate of Achievement 

AGU / FEMA 270 S EISMIC S LEUTHS
4 UNIT RESOURCES 

Books 

Arnold, Christopher, and Reitherman, Robert. (1982). 

Building Configuration and Seismic Design. New 

York: John Wiley and Sons. 

Federal Construction Council Consulting Committee 

on Civil and Structural Engineering. (1992). Base 

Isolation for Seismic Safety: Summary of a 

Symposium. Washington, DC: National Academy 

Press. Summaries of nine papers describing the theory 

and practice of base isolation. 

Federal Emergency Management Agency. (October 

1990). Non-Technical Explanations of the NEHRP 

Recommended Provisions. FEMA 99. Washington, 

DC: Building Seismic Safety Council. Explains the 

necessity of a building code and how earthquakes 

affect buildings. 

Lagorio, Henry J. (1990) Earthquakes—An Architect’s 

Guide to Nonstructural Seismic Hazards. New York: 

John Wiley and Sons. 

Moore, Gwendolyn B., and Yin, Robert K. (1984). 

Innovations in Earthquake and Natural Hazards 

Research: Synthetic Accelerograms. Washington DC: 

Cosmos Corporation (202-728-3939). Discusses the 

use of computer-derived earthquake simulations to 

predict how buildings will respond to earthquake 

shaking. 

Plafker, G., and Galloway, J.P., eds. (1990). Lessons 

Learned from the Loma Prieta, California, 

Earthquake of October 17, 1989. U.S. Geological 

Survey Circular 1045. Washington, DC: U.S. 

Geological Survey. 

Salvadori, M. (1990). The Art of Construction.

Chicago, IL: Chicago Review Press. Simple and 

readable, expressly written for young readers. 

Periodical Articles 

Bedway, B. (Feb. 23, 1990). “Building for a 

Landscape on the Loose.” Science World, pp. 9+. For 

ages 12–15. 

Boraiko, AA. (1986). “Earthquake in Mexico.” 

National Geographic 169: 655–675. 

Brady, Gerry. “Desk Top Model Structure for 

Dynamic Earthquake Demonstrations.” U.S. 

Geological Survey. Applies simple models to predict 

natural frequency. Plans provided for constructing 

models of strong column/weak beam and weak 

column/strong beam buildings, plus descriptions of 

buildings’ reactions to earthquakes and explanations 

for the results. 

Robison, Rita. (November 1989). “Isolated Examples.” 

Civil Engineering: 64–67. Describes base isolation in 

practice. 

Rosenstock, L. (March 17, 1989.) “Can Buildings Be 

Made to Survive Earthquakes?” Current Science, pp. 

6–7. For ages 10–16. 

Taries, Alex. (April 1993). “First U.S. Application of 

Seismic Base Isolation.” Phenomenal News: Natural 

Phenomena Hazards Newsletter: 1-4. 

Non-Print Media 

The Great Quake of ‘89. Videodisc and Macintosh 

software. Includes segments taken from ABC news 

coverage showing actual damage to the Bay Bridge, 

Highway 880, the San Francisco Marina, and the 

downtown. The Voyager Company, Santa Monica, 

CA; 310-451-1383. 

Note: Inclusion of materials in these resource listings does 

not constitute an endorsement by AGU or FEMA. 

AGU / FEMA 271 S EISMIC S LEUTHS
UNIT FIVE 
5 INTRODUCTION 

What Should People Do Before, 

During, and After an Earthquake? 

Following the pattern established in earlier units, this 

set of lessons returns students from model structures to 

the actual structures in their own community. Some of 

the activities will require outside help. The relationships with experts in the community that you and your 

students established in Unit 1 and have developed in 

subsequent units will stand you in good stead. 

In Lesson 1, students explore the tantalizing possibilities of earthquake prediction. The first activity is 

based on an actual series of events stemming from one 

rather ambivalent recent prediction of an earthquake 

on the New Madrid Fault, the site of the most widely 

felt earthquake in U.S. history in 1811-1812. Students 

read accounts of the prediction and its aftermath, 

discuss the reactions of different groups, and learn 

how to evaluate such a prediction. In the second 

activity they consider levels of probability and 

categorize various scientific and nonscientific 

approaches to predicting earthquakes. When they have 

finished these activities, they will realize they cannot 

place their faith in any warning system currently 

available. Their best bet, wherever they live, is to be 

prepared for earthquakes and other natural disasters. 

Lesson 2 begins where the students are, in school and 

at home. The first activity is an earthquake and 

evacuation drill, followed by a classroom hazard 

assessment. The earthquake and evacuation drill is 

absolutely basic for your students’ safety; do not omit 

this lesson. Even if your students do not live in an 

earthquake-prone area now, they may someday. 

Students develop a checklist for home hazard assessment in the second activity of Lesson 2. In Lesson 3, 

they learn the elements in the construction of a typical 

wood frame house by visiting a house to inspect its 

foundation and other structural elements. They 

complete a checklist and take home detailed instructions for reinforcement projects they can do with the 

assistance of a parent or other adult. 

Moving out into the community, in Lesson 4 students 

evaluate the potential earthquake damage to various 

structures in their community. They will conduct a 

sidewalk survey to estimate vulnerability of buildings 

to earthquake damage. Engineers and other experts 

you contacted earlier will provide valuable assistance 

in this project. They can not only help students to 

generate data, but also advise them on how to interpret 

it. 

Lesson 5 builds directly on work students did in Unit 1 

to assess their own community’s vulnerability. In this 

activity they will see the relationships of various 

secondary disasters to the earthquake that initiates 

them and describe how local emergency services 

would work together to alleviate their effects. The 

community map begun in Unit 1 and elaborated in 

Unit 2 will be further developed in this activity. 

AGU / FEMA 272 S EISMIC S LEUTHS
5.1 

Predicting

VOCABULARY

Prediction: a statement 

that something is likely 

to happen based on past 

experience. A prediction 

ACTIVITY ONE 

I READ IT IN THE NEWSPAPER

RATIONALE 

By reading newspaper accounts of an earthquake “prediction” or 

forecast that proved to be false, students will learn to be critical 

consumers of media reports. They will analyze the content of articles 

spanning more than a year and compare the varying reactions of 

different people and groups. 

FOCUS QUESTIONS 

What would you do if an earthquake was predicted for your town? 

OBJECTIVES 

Students will: 

1. Read media accounts analytically. 

2. Visualize the effect of an earthquake prediction on a community. 

3. Know how to obtain reliable earthquake information from the 

appropriate government agencies. 

MATERIALS

Q Student copies of Master 5.la, Newspaper Accounts (6 pages) 

Q Paper and pencils or pens 

is usually only as reliable as its 

source. 

Probability: in mathematics, the 

ratio of the number of times 

something will probably occur to the 

total number of possible 

occurrences. In common usage, an 

event is probable, rather than merely 

possible, if there is evidence or 

reason to believe that it will occur. 

Retrofitting: making changes to a 

completed structure to meet needs 

that were not considered at the time 

it was built; in this case, to make it 

better able to withstand an 

earthquake. 

TEACHING CLUES AND CUES 

According to the Federal 

Emergency Management Agency (FEMA), 

an earthquake prediction 

PROCEDURE 

Teacher Preparation 

Read the articles before you distribute them to students. Outline the 

highlights of each article, especially noting the effects of the forecast 

upon the community, how the forecast is reported slightly different in 

each story, and the response of governmental agencies. 

must include time, place, magnitude, 

and probability. An earthquake 

forecast is much less precise. 

A. Introduction 

Tell the class that in the fall of 1989, climatologist Iben Browning 

reportedly predicted that an earthquake of magnitude 6.0 or greater 

AGU / FEMA 273 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

The second activity in 

this lesson, Faulty 

Reasoning, reviews the 

federal government’s 

would occur on December 3, 1990, plus or minus 48 hours. However, 

his forecast also said that the earthquake would occur between the 

30° N and 60° N lines of latitude, an area that encircles the Earth. 

According to scientists, the probability that a seismic event of 

magnitude 6.0 or greater will happen in such a broad zone of the 

Earth’s surface is actually very high. 

However, the media reported that Browning had specifically predicted 

a catastrophic earthquake in the highly seismic area of New Madrid, 

Missouri, which in 1811-12 was the epicenter of the most powerful 

earthquakes ever recorded in the continental United States. People in 

the New Madrid area reacted to the continual flow of media coverage 

about the impending quake by stocking up on food and water, 

purchasing expensive earthquake insurance, making plans to travel to 

distant places, developing emergency community preparedness plans, 

and retrofitting buildings. School systems even scheduled “earthquake 

breaks.” On the day of the predicted seismic event, the little 

midwestern town of New Madrid was overrun by the television and 

newspaper media. 

official protocol for assessing 

earthquake predictions. 

B. Lesson Development 

1. Divide the class into groups of four or five students each and 

distribute at least two newspaper articles on Master 5.la to each group. 

Instruct students to read the articles and take notes individually, then 

discuss what they have read. Student notes should answer the 

following questions: 

Q How did government agencies react to the prediction? 

Q How did the scientific community react? 

Q How did some entrepreneurs react (people who saw an opportunity 

to make money)? 

Q How did many laypeople react? 

2. Now ask students in each group to pool their notes and write a brief 

team report that covers the following points: 

Q How did Iben Browning arrive at his prediction? 

Q How did the people of the New Madrid seismic zone and 

surrounding, areas react to the media coverage? 

Q How did the scientific community react? 

Q How did the news media react? 

Q In your opinion, which governmental agencies should citizens 

consult to obtain information about the accuracy of earthquake 

forecasting? 

Q How would personally react to headlines and newspaper accounts of 

a devastating earthquake that was forecast for your home town? 

3. Invite teams to orally present their reports to the class. When all 

groups have reported, discuss and analyze the teams’ conclusions in 

light of new information from other teams. Encourage students to 

point out discrepancies among the various reports. (Iben Browning’s 

AGU / FEMA 274 S EISMIC S LEUTHS
doctoral degree, for example, is variously reported as being in physiology, in climatology, in zoology, in biology, and in genetics and 

bacteriology.) Point out, however, that the pages were originally arranged 

in chronological order, so it takes the full set to tell the full story. No one 

group will have as much information as the class as a whole. 

C. Conclusion 

Invite discussion of the nature of Browning’s earlier “successful” 

predictions. Could they have been of the same open-ended nature as 

this one? How difficult is it to successfully predict an earthquake after 

it has happened? 

Be sure students know where to obtain accurate earthquake information: from the U.S. Geological Survey, the Federal Emergency 

Management Agency, their state office of emergency services, and the 

state geological surveys. (The latter have various names, such as the 

California Governor’s Office of Emergency Services, the Missouri 

Emergency Management Agency, the Vermont Division of 

Emergency Management, and the Utah Division of Comprehensive 

Emergency Management.) Check the resource list in Unit 1 and your 

local telephone books for these listings. 

ADAPTATIONS AND EXTENSIONS 

1. According to the articles, Browning specified a time period that 

would coincide with the Moon’s maximum gravitational attraction 

upon the Earth. Ask students how they would set up a test to 

demonstrate that the Moon affects earthquake or volcano activity. 

2. Distribute copies of the August 1991 article, the last in the set, to 

every student, or read it aloud with the class. Discuss the conclusion 

that the scientific community was partly to blame. 

ACTIVITY TWO 

FAULTY REASONING

RATIONALE VOCABULARY 

Because of the randomness of seismic events and the fact that scientific 

understanding about earthquake-generating mechanisms is still evolving, earthquake prediction today is imprecise, indeed even speculative. 

Generalization: a 

statement made after 

observing occurrences 

that seem to repeat and 

to be related. 

FOCUS QUESTION 

Why is predicting earthquakes not an exact science? 

OBJECTIVES 

Students will: 

1. Explain the purpose of predicting earthquakes. 

2. Identify several types of seismic predictions. 

3. Explain why earthquake prediction is complex and based largely on 

probability. 

AGU / FEMA 275 S EISMIC S LEUTHS
AGU / FEMA 276 S EISMIC S LEUTHS

M A T E R I A L S TEACHING CLUES AND CUES 

Q Chalkboard or overhead projector, chalk or markers 

Q Student copies of Master 5.1b, Approaches to Predicting 

Earthquakes 

Point out that the degree 

of probability is an 

essential element in prediction. You can predict 

Q Student copies of Master 5.1c, Levels of Generalization: 

Classification Chart 

Q Back of Master 5.1c, Answer Key 

with a probability of 99.9% that an 

earthquake of magnitude 2 will occur 

in southern California tomorrow. For 

larger quakes, the degree of probability drops sharply. 

PROCEDURE 

A. Introduction 

Tell students that with increasing numbers of the world’s people living 

in active earthquake zones, earthquake prediction or forecasting has 

been receiving more and more attention in recent years. Begin by 

asking students to name some advantages of being able to predict 

earthquakes. Record responses on the overhead or chalkboard. (Likely 

answers will include saving lives and reducing property loss and 

damage, providing guidelines for development and human settlement, 

providing valuable data for the scientific community, helping people 

to prepare for earthquakes on both a short-term and a long-term basis, 

and allowing communities to return to normal more quickly after an 

earthquake.) 

Ask: Would there he any disadvantages to being able to predict or 

forecast earthquakes? (Answers might include financial losses to 

businesses forced to close and the anxiety people would feel if they 

knew an earthquake was imminent. 

Lesson Development 

1. Ask: Are we, in fact, able to predict or forecast earthquakes with 

any certainty? Students may have heard of some theories and attempts 

at prediction, but they will also know that earthquakes have claimed 

lives and property in recent years. If earthquake prediction was an 

exact science, these losses would have been greatly reduced. 

Remind students that while significant efforts at developing systems of

accurate prediction are underway in earthquake-prone countries like 

Japan, the United States, and the People’s Republic of China, 

seismologists are still a long way from accurate prediction. Point out 

that of the several types of phenomena that may predict an earthquake, 

many may be due to other causes and yield false alarms. 

2. Organize the class into groups of three of four students each. Have 

all the students in each group list these terms at the top of a blank 

sheet of notebook paper: time, magnitude, place, and probability. Ask 

each group to write briefly how they think these terms relate to 

seismic prediction and why they are important. Also discuss the idea 

of coincidence, versus that of causality. For example, a sunrise occurs 

within 24 hours of every earthquake, but sunrises cannot be said to 

cause earthquakes. 
AGU / FEMA 277 S EISMIC S LEUTHS

TEACHING CLUES AND CUES 

According to Bruce Bolt 

(Earthquakes, 1993 

edition, p. 185), the 

methods of prediction 

3. After several minutes, ask one student in each of the groups to 

summarize the group’s findings. While answers may vary, the pattern 

of response should consistently indicate how helpful such precise 

information would be to surviving an earthquake with minimum loss 

of life and property damage. 

4. Write this statement on the overhead or chalk board: “Earthquake 

prediction or forecasting takes place at several levels of generalization 

and involves various approaches.” Stress the term generalization, so 

students will recognize that prediction is broadly based and in many 

instances, largely theoretical. 

5. Distribute copies of Master 5.lb and instruct students to classify 

each of the approaches to predicting earthquakes listed into one of the 

three categories on the table that follows. Their challenge is to 

organize the data about earthquake predictions into a chart classifying 

different kinds of information. 

6. When the students have developed the charts, allow time for sharing 

and comparing answers. The important element in this part of the 

activity is not that students make the “right” classification, but that 

they can defend their reasoning. 

C. Conclusion 

Explain to the class the federal government’s official protocol for 

evaluating earthquake predictions. 

The National Earthquake Prediction Evaluation Council (NEPEC) 

convenes to hear evidence for the prediction of an earthquake above 

magnitude 5.5. If the NEPEC validates the prediction, the following 

will occur: 

that currently show the most promise 

require elaborate equipment and 

many workers, so that their cost is 

likely to be prohibitive. 

Issuance of Earthquake Predictions. The Director of the 

United States Geological Survey (USGS) is hereby given the 

authority, after notification of the Director of the Federal 

Emergency Management Agency (FEMA), to issue an 

earthquake prediction or other earthquake advisory as he [sic] 

deems necessary. ... The Director of FEMA shall have 

responsibility to provide state and local officials and residents 

of an area for which a prediction has been made with 

recommendations of action to be taken. 

Public Law 95-124, Earthquake Hazards Reduction Act, 

as amended [P.L. 96-472] 

Add that the USGS also issues earthquake advisories. The state of 

California has its own earthquake prediction evaluation council and its 

own notification protocol. 

Ask students to review the notes they have taken and the chart data 

they have organized, then select the theory or approach that seems 

most plausible to them. As homework or in class, each may write a 

personal prediction of how this approach will be developed and 

refined in the coming years. Students may want to defend their 

predictions in a class discussion. 
AGU / FEMA 278 S EISMIC S LEUTHS

ADAPTATIONS AND EXTENSIONS 

1. It may be useful to illustrate the concept of mathematical 

probability with dice or the toss of a coin. The probability of heads in 

a coin toss is 50-50. 

2. Invite interested students to learn more about some of the scientific 

prediction methods, such as creep meters and radon monitoring, and 

report back to the class. Consult the unit resources and your local 

libraries. V
5.1a MASTER PAGE Newspaper Accounts

AGU / FEMA 279 S EISMIC S LEUTHS

Volume 1 “News of Geologic Importance” Issue 1 

From the Dallas Morning News, July 22, 1990 

Prediction prompts residents 

to wonder, worry

From the Arkansas Democrat, 

November 29, 1989 

New Madrid 

tremors due, 

forecast says 

MEMPHIS, TN—A climatologist who predicted the San Francisco earthquake Oct. 17 

says the New Madrid Fault region could be in

for serious tremors next year. 

Iben Browning is a Tijeras, NM, scientist

who develops long-range weather forecasts 

for businesses. He bases his quake predictions 

on the theory that tidal forces of the Sun and

Moon produce stress in the Earth. 

Browning, an inventor with a doctorate in

physiology, has studied weather for 30 years, 

but does not publish his findings in scientific 

journals. He is better known in business circles, and publishes a monthly newsletter. His 

New Madrid forecast is based on a 179-year

cycle of tidal forces last felt in 1811. 

Browning said the conditions will be ripe for

tremors Dec. 3, 1990. 

“The configuration will be the same as it

was the year the original earthquake went

off,” Browning said Monday. 

That isn’t to say tidal forces would cause 

a major earthquake next year south of St. 

Louis to a point north of Memphis, he said. 

Experts have predicted a major

earthquake in the New Madrid zone could

cause major damage to match that of the 

recent California quake. 

Dr. Arch Johnston, director of the Center

for Earthquake Research and Information at

Memphis State University, said the tidal force 

theory is backed by some scientific data, but

isn’t conclusive by any means. 

THE NORTHEAST ARKANSAS TOWN 

OF 25,000—a county seat with Air Force 

base and several small industries—is 

perched directly over the site of [Iben 

Browning’s earthquake] prediction. 

Knowing what lies beneath the flat delta 

farmland clearly makes some uneasy. 

“Our fire chief told our firemen they 

can’t take a vacation. Some already asked,” 

said Mr. Edwards, a Fire Department lieutenant. “He said we could ship our families 

out, but we’re staying. It was said kind of in 

a jest, but I think that everyone is actually 

pretty serious about this.” 

One geophysicist studying Dr. Browning’s methods says the projection can’t be 

ignored because he had predicted other

earthquakes—including last October’s California temblor. 

But most experts dismiss the warning. 

They acknowledge that there is a 50-50 

chance that a destructive quake will hit the 

fault by decade’s end, but they say the projection lacks scientific validity. 

“It seems like people are becoming worried about it for no reason at all,” said Dr. 

Brian Mitchell, chairman of the Department 

of Earth and Atmospheric Sciences at St. 

Louis University. 

At the center of the furor is an ailing 72- 

year-old inventor from Tijeras, NM, who 

has spent much of the last 20 years offering 

clients advice on the esoteric topic of future 

world climates. 

Dr. Browning declined to be interviewed. But his daughter, Evelyn Browning 

Garriss, said her father began forming his 

wide-ranging theories while working at 

Sandia Laboratories in Albuquerque, NM. 

Dr. Browning has a doctorate in biology 

from the University of Texas, and Ms. 

Garriss said his interests range across many 

fields. She said he has been a test pilot and

developed weaponry and TV technology. 

Ms. Garriss said the ideas that spawned

her father’s latest projection arose from

research for the U.S. government on peaceful uses for atomic bombs. While studying 

how explosions affect the atmosphere, she 

said, he became fascinated with volcanoes. 

He found that volcanoes are triggered by the 

same gravitational pulls that cause ocean

tides, and he “discovered that the same forces 

that trigger volcanoes also trigger

earthquakes,” she said. 

That theory produced his projection of an

earthquake on the New Madrid Fault. Although rejected by most scientists, Dr. 

Browning’s new warning has gained attention

from many in a region already worried about

the New Madrid Fault’s potential for

destruction. 

Some earthquake-preparedness efforts 

have been underway for six years because 

seismologists warned in the early 1980s that a

temblor measuring 6.0 on the Richter scale 

had a 50-50 chance of occurring before 2000. 

Indiana, Kentucky, Missouri, and the cities of

Carbondale, IL, Memphis, TN, and St. Louis 

have approved seismic building codes in the 

past two years. 

Since 1984, seven states and the Federal 

Emergency Management Agency have developed a regional emergency response system through the Central U.S. Earthquake 

Consortium in Memphis. 

Most state officials place little stock in

the prediction, but they hesitate to reject it for

fear of encouraging complacency about real 

threats posed by the fault. Mississippi 

officials are accelerating preparedness planning. And in Illinois, officials are forming a

plan to address panic that might result if any 

detectable tremors hit the region near the 

predicted date, said Tom Zimmerman, the 

state’s emergency planning director. 

To further soothe regional concerns, state 

emergency officials want scientific experts to 

formally evaluate the prediction. Several state 

officials said they have asked the National 

Earthquake Prediction Evaluation Council, 

based in California, to address the issue. 

The council of pre-eminent earth scientists has turned down the request. 

“They don’t want to glorify the 

prediction,” Dr. Mitchell said. 
MASTER PAGE 

San Francisco Chronicle, July 25, 1990 

AGU / FEMA 280 S EISMIC S LEUTHS

What If He’s Right? 

by Jerry Carroll

ALBUQUERQUE, NM—The scariest man in

America walked through the door with his

predicting the eruption of Mount St. Helens on

May 18, 1980. In this latter instance he was

fields of bio-engineering, computers, electronics, environmental systems, information theory, microbics, microminiaturization, optics, 

and space navigation. 

 “I was a test pilot in Victorville [CA], flying two-engine and four-engine airplanes.”

While fello pilots drank beer after ork
MASTER PAGE 

America walked through the door with hi

AGU / FEMA 281 S EISMIC S LEUTHS

s

daughter, looking with his bald head and spectacles like everybody’s idea of a nice grandpa. 

Given what we were going to talk about, I half

expected to see Iben Browning in long robes

and a tall wizard’s list. 

He told audiences before last October’s

earthquake that the earth was going to move

in the Bay Area, and now he says there is a

50-50 chance there’ll be a major earthquake

December 3 on the New Madrid Fault in

Missouri, on the Haywood Fault in East Bay, 

or in Tokyo. 

Browning bases his forecasts—which he

calls mathematical calculations about the pressures the Sun and Moon exert on the Earth’s

surface—on forces he says have a profound if

little known effect on the course of civilization. 

While his projections fascinate the media, 

they leave the science community with a

healthy dose of skepticism. 

“No evidence,” say some. 

Scientists who have studied tidal influences

of the Sun and the Moon have come up with

no evidence that they trigger earthquakes, said

James Dorman, associate director of the Center

for Earthquake Research and Information at

Memphis State University. In 1972, Dorman

studied 30,000 earthquakes looking for a correlation, but failed to find one. “Browning has

not convinced anyone he knows what he’s

doing,” he said. 

But Browning has his believers. 

The New Madrid Fault was responsible in

1812 for the mightiest earthquake in American

history. Estimated at more than 8.5 on the

Richter Scale, it toppled chimneys in

Cincinnati, made church bells ring in Boston, 

and awakened James Madison in the White

House and Thomas Jefferson in Monticello. A

similar quake today could claim hundreds of

thousands of lives and cause more than $50 

billion in damages. 

The South Mississippi County School

District No. 57 in Arkansas, for one, thought

enough of Browning’s warning to cancel classes December 3 and 4. The Missouri and

Arkansas National Guards are planning earthquake exercises those days. 

In a memorandum last month to midwestern

earthquake experts and the Missouri Emergency

Management Agency, David Stewart of the

Center for Earthquake Studies

at Southeast Missouri State University in Cape

Girardeau, MO, wrote: “That he was correct in the Loma Prieta event is a verifiable

fact.” 

Furthermore, Stewart continued, “He was

also apparently correct within a few days of 

May 18, 1980. In this latter instance he was

speaking before a group of several hundred in

Portland, OR, on May 15, 1980 when he told

them it would go in about a week.” The volcano, dormant for 123 years, had been threatening to blow since March 27. 

Stewart said: “His calculations had also 

picked the dates of Sept. 19, 1985, and Nov. 

13, 1985, upon which the Mexico City earthquake and the Nevado del Ruiz volcano eruption in Columbia, respectively, occurred.” 

The memo, which was leaked, got Stewart

in hot water. “He swallowed Browning’s story

hook, line, and sinker,” Dorman said. “Stewart

did not boost his own stock in the scientific 

community.” 

A Visionary? 

So who is this man and how can he appear to do 

with a sharp pencil what seismologists

can’t, for all their high-tech laser beams, strain

gauges, and tilt and creep meters? Is he a seer, 

a visionary who screws his eyes shut and holds

a finger to his temple? 

Do we lump him in the same category as

Jim Berkland, the Santa Clara County geologist who says he predicts earthquakes using

a theory based in part on how many pets run

away from home? 

“He has an intellect like a giant,” said

Dwaine W. Rogge, president and founder of the

Commerce Financial Group in Lincoln, NE. 

“He must have an IQ of 200-plus,” said agricultural specialist Roger Spencer, a first vicepresident of Paine-Webber of Chicago. 

The two of them, like the majority of

Browning’s clients and the subscribers to his

monthly newsletter, rely on him for help in

investments and business decisions based on

Browning’s analysis of climatic trends. Before

diabetes limited his mobility, Browning shared

top billing at business and economic conferences with the likes of Milton Friedman and

Henry Kissinger. He spoke 40 to 50 times a

year, getting $2,500 for his talks. “Earthquake

projections,” Browning told me, “are purely a

sideline, one that has really become a nuisance.” 

He said that he made only seven projections about earthquakes or volcanoes erupting

and has been right each time. It doesn’t bother him that his fellow scientists ignore him. 

Given his lack of formal credentials in the field, 

it’s to be expected, he said. “Anyway, I’m not

talking to them. I’m talking to my clients.” 

Scientist, Master Consultant 

Browning is primarily an inventor. He has 67 

patents, the most recent for a high-definition

television system licensed to the Japanese. He

has been a consultant for business in the 

While fellow pilots drank beer after work, 

Browning, who has total recall, stuffed his

mind with the Encyclopedia Brittanica. “I read

articles at random, integrating them into what

I already knew.” By war’s end, he had read

more than a thousand. 

After the war, he got a master’s degree from

the University of Texas in physics and bacteriology and a doctorate there in genetics and

bacteriology. 

Military Consultant 

When he wasn’t inventing, Browning worked

as a consultant for defense industries. But

while studying the effects of atomic bombs for

the Sandia National Laboratories in 1957, he

realized they were puny compared to the

power unleashed by volcanic eruptions. 

That’s when he began his study of climate, 

immersing himself in several scientific disciplines in a manner not often done in an age

of narrow specialization. The data he consulted ranged from magnetic field intensities during ancient Egyptian dynasties to records of

lynx pelts bought from trappers by Hudson Bay

Co. in the 17th century. 

He became convinced that earthquakes

and volcanic eruptions were triggered by

sunspot activity and the pull of the Sun and

Moon on the Earth’s brittle crust—the tidal

effect. 

Seismologist William Ellsworth of the U.S. 

Geological Survey in Menlo Park, a major

leader in quake research, says, “If there is a

tidal effect, it clearly is not something either

universal or of any practical importance.” 

At least two other scientists agree. 

Brian Mitchell of the Department of Earth

and Atmospheric Sciences at St. Louis

University and Arch Johnson of the Center for

Earthquake Research in Memphis wrote disaster officials in the New Madrid Fault area

pointing out that of five earthquakes Browning

said were triggered by tidal forces, only one

occurred during a high-tide period. 

“I don't think the prediction is anything we

should pay attention to,” Mitchell said. 

Not Over Yet 

Browning says that even if December 3 (when

tidal forces hit a 27-year high) arrives and it

turns out that seismic pressures here, in

Missouri, and Japan haven’t yet built to the

point where earthquakes are triggered, that

doesn’t mean we’re out of the woods. January

19, 1992, will bring on the highest highs in

more that 1,600 years. 

You’re a pessimist, I said. “No I’m not,”

Browning replied with equanimity. “Man will

survive. He always has.” 
MASTER PAGE 

The Dallas Morning News, July 26, 1990 

Experts to evaluate earthquake warning 

by Lee Hancock

The U.S. Geological Survey will officially

evaluate a New Mexico man’s warning that

an earthquake may rock the central United

States on Dec. 3, 1990, an agency official

said Wednesday. 

Walter Hays, an official with the

Geological Survey in Washington, said the

agency would convene a panel of geologists

and seismologists from throughout the central United States to study the prediction. 

“We’re not at all impressed with this

forecast,” he said. “On the surface we would

not expect there is any basis for concern. But

we do want to set people at ease and be satisfied in our own minds that we haven’t

overlooked something.” 

The location of the predicted earthquake

is along the New Madrid Fault, which runs

between Marked Tree, AR, and Cairo, IL, 

and has branches in West Tennessee and

the Missouri boot heel. 

Scientists say it is impossible to predict 

exactly when an earthquake will occur. 

However, they say they are trying to estimate the probability of an earthquake along

several highly active faults in the United

States. 

The decision to evaluate the prediction

follows a plea for help by the region’s sevenstate earthquake response coalition, an

agency that has been struggling for more

than a month to address growing regional

fears about the prediction by Iben Browning, 

a self-styled climatologist from Tijeras, NM. 

Dr. Hays said U.S. Geological Survey scientists have considered about 300 predictions since 1977 that ranged from the scientific to the ridiculous. But he said that the

widespread public concern makes Dr. 

Browning’s prediction unique and that it

was the primary reason for the evaluation. 

Dr. Hays said the study probably would

be completed by the end of September. 

The National Earthquake Prediction 

Council, an advisory board of earth science

experts set up by the U.S. Geological Survey, 

last month refused to evaluate Dr. 

Browning’s prediction. “They didn’t want to 

glorify it,” one mid-south seismologist said. 

Dr. Hays said the 13-member council

would evaluate the findings of the regional scientists’ group at the request of the federal geological agency. 

“On the surface we don’t expect to see

any basis for this to be a credible prediction,” he said. “But you have to go through

a process.” 

The council has officially endorsed 13 

predictions since its creation in 1980, said

Dr. Hays, deputy chief for research applications in the Geological Survey’s office of

earthquakes, volcanoes, and engineering. 

The endorsed predictions, which project

activity along faults in Alaska and California

over periods ranging from four to 30 years, 

are still pending, Dr. Hays said. 

The New York Times, August 20, 1990 

Midwest Quake Is Predicted 

by William Robbins

AGU / FEMA 282 S EISMIC S LEUTHS
MASTER PAGE 

NEW MADRID, MO., AUG. 15—Life on th

AGU / FEMA 283 S EISMIC S LEUTHS

e

fault line is always interesting, as people in this

trembly old Mississippi River town often say, 

but a prediction by a man named Iben

Browning is making life hereabouts downright exciting. 

Dr. Browning, a climatological consultant

from New Mexico, has calculated that on Dec. 

3, give or take 48 hours, this area could once

again be the center of a destructive earthquake. 

People in Missouri and neighboring states are

taking his prediction seriously enough to plan

events like National Guard drills and informational town meetings, to store food, and to 

consider closing schools on the appointed day. 

There is considerable skepticism among

experts and residents of this area about Dr. 

Browning’s prediction, which involves calculations of tidal forces resulting from the gravitational effects of the Earth, the Moon, and

the Sun. But New Madrid is conditioned by its

history to take a sober view of warnings. 

This town is near the epicenter of one of

the most devastating earthquakes ever recorded in North America. A series of quakes, beginning with a colossal shock, struck at 2 a.m. on

Dec. 16, 1811, while settlers and Indians in the

Mississippi River frontier slept. Tremors shook

the earth almost continuously for months, and

two even greater shocks struck on Jan. 23 and

Feb. 7, 1812. 

Debate on Predictability 

Seismologists say it is impossible to predict

when another big earthquake might strike. But

based on what they know of geologic 

conditions, they calculate that there is a 50 

percent chance for a 6.3-magnitude quake by

the end of the decade and a 90 percent chance

for such a

quake by 2040. 

Most scientists doubt the ability to pinpoint

the date of an earthquake. But at least one, 

David Stewart, director of the Earthquake

Information Center at Southeast Missouri

State University in nearby Cape Girardeau, 

says he has looked into Dr. Browning’s previous predictions and accords him respect. 

Dr. Browning’s previous warnings have

been widely reported in another quake-skittish

locale, San Francisco. He is known to have predicted the 1989 San Francisco earthquake a

week in advance in an appearance before

about 500 business executives and their wives

at a convention. He is also said to have predicted the eruption of Mount Saint Helens in

1980. 

Like the experts, the people with the

biggest stake in the debate, those who live here, 

are also divided on Dr. Browning’s prediction. 

Don Lloyd, the city administrator, typified

the most optimistic stance. “We know it’s coming sometime, but it’s just as likely to happen 

tomorrow as next Dec. 3,” he said the other day. 

Most people are like the police chief, Jimmy 

Helines, or officials of the National Guards of

Missouri and Arkansas. While they are not

panicking, they see nothing wrong with taking precautions, either. 

Missouri’s Army National Guard is planning earthquake exercises Oct. 13 to 14, and the

Arkansas National Guard is planning a

similar drill Dec. 1 to 5. “We were planning

an exercise anyway,” said Maj. Cissy

Lashbrock, the Arkansas Guard’s public information officer. “But Browning has attracted so 

much attention, this looked like a good time

to let people know we do have a plan.” 

Mr. Helmes has planned to store food and

water supplies in a warehouse and to station

school buses nearby for emergency transportation. Mayor Dick Phillips and Mr. Lloyd

are planning a town meeting at which Dr. 

Stewart will discuss precautions. 

In addition, officials of a few schools in

nearby towns are considering closing them for

the day. Gerald Murphy, a high school coach, 

wants his wife, Beth, to take their baby and

got out of town, and James and Gloria Taylor

of nearby Lilboum are planning to take their

daughter and son-in-law on a trip on the first

weekend in December. 

See Quake (next page) 
MASTER PAGE 

Quake (from previous page)

The talk has naturally focused attention

on the man who made the prediction. 

Dr. Browning’s academic background is in

mathematics, physics, and microbiology, and

his doctorate, in biology, is from the University

of Texas. He is also a self-taught climatologist

and serves as a consultant on the subject to 

many businesses and executives. 

“No Public Pronouncements”

“I make no public pronouncements,” the 72-

year-old scientist said in a telephone interview

from his home in Sandia Park, NM. “What I

say is for my clients.” He said predictions that

have surfaced publicly have been recounted by

members of private audiences. 

It was at a convention of the Equipment

Manufacturers Institute in San Francisco that

he said his calculations indicated an earth 

quake there about Oct. 16, the day before it

occurred, and one on Dec. 3 in the New Madrid

The Wall Street Journal, September 18, 1990 

Will the Earth Move on Dec. 3? 

Midwest Is Rattled By a Scientist’s Prediction of a Major Earthquake 

by Michael J. McCarthy 

AGU / FEMA 284 S EISMIC S LEUTHS
MASTER PAGE 

area. 

AGU / FEMA 285 S EISMIC S LEUTHS

Emmett Barker, president of the institute, was present and heard the predictions. 

Regarding Dr. Browning’s method, Brian

Mitchell, chairman of the Department of Earth

and Atmospheric Sciences at St. Louis

University, said, “Recent studies with the best

available data show no correlation between

tidal forces and earthquakes.” 

And Pat Jorgenson, a spokeswoman for the

United States Geological Survey in Menlo 

Park, CA, said scientists there “are not at this

time doing any research into earth tides and

any possible relation to seismic activity,”

although they are aware “that this is a muchdiscussed proposition.” She said that the agency’s scientists had conducted studies on the

claims but that these “proved inconclusive.” 

Still, Dr. Stewart, of Southeast Missouri

State, said he thinks Dr. Browning’s method

should not be summarily rejected. “Here’s a

man who has hit several home runs,” he said. 

“Will he hit another on Dec. 3? We don’t know, 

but that’s no excuse for not being prepared.” 

MEMPHIS, TENN.—Friday nights used to be

slow at The Fault Line, a nightclub here on

busy Poplar Avenue. But after word spread

that a major earthquake was forecast for Dec. 

3 in the Midwest, The Fault Line began throwing earthquake parties. 

On Friday nights now, hundreds of patrons

pour into the club to swig “Earthquake

Shooters” and sign up to win December

Earthquake Escape Packages to the Bahamas

or Hot Springs, AR. 

But even as Memphians whoop it up, the

prediction that the Big One may come this

December is triggering tremors up and down

the Mississippi River Valley. Shaken, thousands of people are crowding into earthquake

survival classes. In Arnold, MO, 3,000 people

showed up for one course. 

In Missouri and Arkansas, some schools

and businesses have announced plans to close

in early December. Entrepreneurs are hawking quake survival insurance, survival kits, and

gas-line safety gadgets. 

Some people are planning to flee. “You can’t

run from everything,” says Tammy

McCormick, a nurse in Bytheville, AR, who 

will take her two youngsters and spend several days with the relatives in North Carolina. 

“But it seems stupid to stay on a fault line

with a prediction like this one.” 

Iben Browning, a 72-year-old scientist, 

predicted October's Bay Area quake a week

before it happened, say people who heard him

speak to the Equipment Manufacturers

Institute. And he predicted “geological disaster” on Sept. 19, 1985, along a band of latitude

that included Mexico City—where a massive

quake struck on that day. 

Mr. Browning, who has a Ph.D. in physiology, genetics, and bacteriology, writes a climate newsletter out of New Mexico. He has 

clients, such as Paine-Webber, Inc., who have

long paid for his wisdom on how the weather

will affect their agricultural investments. 

Since 1971, Mr. Browning says, he has

picked the correct dates of four large earthquakes, two volcanoes—and one day with both

a volcano and an earthquake. 

He bases his forecasts on tidal forces caused

by the positions of the Sun and the Moon— 

an old theory, critics say, that doesn’t wash. 

On Dec. 3, those forces are expected to be at

a 27-year high. Mr. Browning says that will

exert pressure that could trigger faults already

ripe to fail. 

A Skeptical Majority 

Skepticism abounds. “No responsible scientist

can predict an exact day for an earthquake,”

says Brian Mitchell, a quake expert at St. Louis

University, echoing the majority opinion. 

But Mr. Browning shouldn’t be written off

so quickly, says Southeast Missouri State’s Mr. 

Stewart, who recently spent four days with Mr. 

Browning. “He has a methodology that can

determine, plus or minus a window of a day

or two, an enhanced probability of a volcano 

or an earthquake in certain latitudes,” says Mr. 

Stewart. “No one else is able to replicate it, but

that doesn’t mean it’s wrong.” 

Mr. Browning says it’s not easy being on

record with predictions that few other scientists will support. “I feel like a lonely little petunia in a cabbage patch,” he says. But asked if

he enjoys being right, he says, “It’s the only

damn thing that matters. If one is a business

consultant, they don’t pay you for being

wrong.” 

Mr. Browning says he is tentatively booked

to give a talk in Minneapolis on Dec. 3, and

he doesn’t plan to go there via St. Louis. But

he adds: “I highly recommend against panic. 

That will kill more people than earthquakes.” 
MASTER PAGE 

The New York Times, October 19, 1990 

Panel of Scientists Finds No Basis 

For Prediction of Missouri Quake 

ST. LOUIS, OCT. 18 (AP)—Projections of a

major earthquake in the Midwest in early

December are without scientific basis, a group 

of scientists said today. 

The 11 scientists reporting to the United

States Geological Survey said there was a longterm possibility of a major earthquake along

the New Madrid Fault, but said there was no 

credibility in the widely circulated projection

made by Iben Browning, a climatologist and

business consultant based in Sandia Park, NM, 

of a 50-50 chance it will happen Dec. 3. 

Public anxiety over Mr. Browning’s New

Madrid projection has been widely reported, 

coupled with reports that Dr. Browning had

also warned of last year’s Northern California

earthquake a week in advance in an appearance before about 500 business executives and

their wives at a convention in San Francisco. 

The scientific group said today that it had

found no evidence that Mr. Browning had

predicted last year’s earthquake. Mr. Browning

has said the reports of his predictions are based

on accounts from members of the private audiences that he addresses. 

A woman who answered the telephone

Thursday at Mr. Browning’s home and identified herself as his wife said he was unavailable for comment. 

The scientists said a transcript of his Oct. 

10, 1989, speech showed that “his statement

was ‘there will probably be several earthquakes around the world, Richter 6 plus, and

there may be a volcano or two.’ No mention is

made of an earthquake occurring in the San

Francisco area or even California.” 

The scientific group issued its finding at a

news conference in St. Louis. The scientists

who contributed to the report were brought

together from universities and governmental

agencies to evaluate the scientific validity of

Mr. Browning’s projection. 

“Such a projection, especially at the

predicted 50-50 chance level, implies a level

of detailed knowledge that simply does not

exist for the New Madrid or any other fault

zone in the world,” the group said in its reports

for the National Earthquake Prediction

Evaluation Council. 

Mr. Browning bases his projections on the 

forces of tides and gravity. He has said that

for 48 hours before and after Dec. 3, these

forces will be particularly strong. 

“Browning’s correlation of earthquake

activity with danger periods at times of highs in

tidal forces does no better at predicting earthquakes of magnitudes greater than 6.5 than

does random guessing,” the scientists’ report

said. 

The New Madrid Fault runs from Marker

Tree, AR, across southeastern Missouri to 

southern Illinois, and produces hundreds of

small quakes every year, most hardly felt. It

is named for the Missouri town of New Madrid, 

about 140 miles south of St. Louis. 

In 1811-1812, a series of quakes estimated at up to 8 on the Richter scale of ground

motion struck the New Madrid region, causing the Mississippi River to appear to flow

backward and ringing church bells in

Washington, DC. 

Southeast Missourian, Cape Girardeau, MO, Dec. 3, 1990 

‘Circus’ comes to New Madrid: 

Projection puts town in spotlight 

by David Hente, Staff Writer

NEW MADRID—For the past several months, 

tiny New Madrid has been the focus of growing national and international attention. On

Sunday, the media circus came to town. 

The attention was touched off by the projection of climatologist Iben Browning that a

major earthquake could occur along the geological fault named after the town. 

Residents of New Madrid and others who 

live along the fault will learn today if Dr. 

Browning’s projection comes to pass. 

New Madrid, population 3,204, is located

at the head of a large bend in the Mississippi

River, in the Missouri boot heel. 

Until recently, few people outside of this

area had heard very much about New Madrid, 

and even fewer knew how to pronounce the

name of the town correctly (New MAD-rid). 

But Browning’s projection caught the attention of the news media, and New Madrid is

now on the minds of people throughout the

nation and the world. 

Over the weekend, tourists, visitors, and

the news media have flocked into the town. 

“I’ve seen more tourists in the past two 

weeks than I had seen in the past six months,”

said Jean Hanner, manager of Rick’s Texaco, 

located on Main Street a few blocks from the

river. 

As Dec. 3 approached, the media continued to swarm into town. By midday Sunday, 

more than 20 satellite transmission trucks and

vans were parked along the New Madrid levee

and in other parts of town. A network technician said that was more than were at the Super

Bowl game last year. 

The four major networks, CBS, ABC, 

NBC, and Cable News Network, along with

television stations from Atlanta, GA, Chattanooga, 

TN, Louisville, KY, Dallas-Fort Worth, TX, 

Nashville, TN, Kansas City, and St. Louis were

preparing to transmit live coverage Sunday

and Monday via satellite. Numerous other

radio stations and print media reporters were

also on hand. 

AGU / FEMA 286 S EISMIC S LEUTHS
MASTER PAGE 

Research News, August 1991 

The Lessons of Dr. Browning 

by Richard A. Kerr 

When a self-taught climatologist predicted a major quake for the 

Midwest, seismologists ignored him, but leaving the field to 

pseudoscience proved a big mistake.

BOULDER, COLORADO—Jill Stevens wanted to alert millions of Midwesterners to the

earthquake threat beneath their feet. As head

of the information side of the Center for

Earthquake Research and Information at

Memphis State University, she had been warning, with limited success, that much remained

undone to protect the citizenry from rare but

lethal quakes. But to the average

Midwesterner, earthquake country stopped at

the California border, so why worry—until

the winter of 1989, when one Dr. Iben

Browning came along. 

A self-taught climatologist, Browning did

Stevens’ job for her—and more. He predicted

that a catastrophic earthquake would strike the

Mississippi Valley during the first week of

December 1990. The media leaped on the prediction and suddenly the populace became all

too aware of the threat. That might have been to 

the good, says Stevens, except that the prediction was scientifically groundless—and so 

specific and apocalyptic as to provoke near-hysteria. Stevens recalls a 6-year-old girl whose

earthquake fears could not be soothed on the

phone, and elderly callers to her center who 

worried how they would get back in their

wheelchairs after the big one struck. Schools

and factories closed on the target day, 3 

December, and groups such as the Red Cross

wasted precious funds in their efforts to calm

the public. 

Although ultimate responsibility for the

misleading quake prediction has to rest with

Browning (who died 3 weeks ago), Stevens and

others who gathered here last month for the

16th Annual Hazards Research and

Applications Workshop lay a healthy share of

blame at the feet of a group that wanted no 

part of Browning or his prognostications: the

scientific community. “If I have any criticism,”

said Lacy Suiter, director of the Tennessee

Emergency Management Agency, “it’s why the

scientific community that had the ultimate

responsibility didn’t call Browning a quack

early on.” And it was this concern that led participants of the meeting to hope that the next

time a bogus earthquake prediction surfaces— 

and there are sure to be more—scientists will

recognize its potential for touching off a frenzy and promptly do their part to squelch it. 

AGU / FEMA 287 S EISMIC S LEUTHS
MASTER PAGE Approaches to Predicting 

Earthquakes

5.1b 

Attempts to predict or forecast earthquakes have been based on these approaches, among others: 

1. Recognizing that seismic activity concentrates in zones of plate tectonic activity 

2. Observing and recording the abnormal behavior of animals 

3. Monitoring seismic activity at plate boundaries 

4. Observing and recording persistent changes in the elevation of given topographic survey points 

5. Locating and monitoring faults in places other than plate boundaries 

6. Compiling data on the seismic history of a given area and measuring the intervals between 

previous quakes 

7. Monitoring the changes in emission of radon (radioactive gas) from rocks by electronic monitoring of deep wells 

8. Monitoring the level of the water in wells 

9. Measuring variations in the magnetic field of large rock formations 

10. Trenching across a fault to uncover evidence of past earthquake movement 

11. Detecting strain in the rocks of the Earth’s crust by geodetic surveys 

12. Using creep meters (wire strands extending across a fault) to indicate stress and movement 

l3. Recording variations in the speed of waves in the swarms of tremors that frequently precede 

earthquakes 

14. Talking to earthquake survivors and recording their descriptions of past quakes 

15. Observing foreshocks and measuring variations in P waves 

16. Placing a network of seismograph stations on the ocean floor across the continental shelf and an 

ocean trench 

17. Monitoring selected sites in an area that has no history of major seismic activity to detect 

micro-earthquakes 

18. Monitoring changes in the occurrence of micro-earthquakes. 

AGU / FEMA 288 S EISMIC S LEUTHS
AGU / FEMA 289 S EISMIC S LEUTHS
MASTER PAGE 

Levels of Generalization 

Classification Chart

5.1c 

Name ___________________________________________________________ Date _____________________ 

Directions: Place the number of each item on the preceding list in the category you think is most appropriate. 

Subjective Observation Seismic Zone Analysis Instrumentation and Measurement 

AGU / FEMA 290 S EISMIC S LEUTHS
MASTER PAGE 

Levels of Generalization 

Classification Chart (key) 5.1c 

Suggest answers 

(Note that some items may belong in either of the last two categories.) 

Subjective Observation Seismic Zone Analysis Instrumentation and Measurement 

2, 14 1, 3, 6, 10, 12, 16 4, 5, 6, 7, 8, 9, 11, 12, 13, 15, 16, 17, 18 

AGU / FEMA 291 S EISMIC S LEUTHS
5.2 

Starting Here, Starting Now 

VOCABULARY 

Aftershock: an earthquake that follows a 

larger earthquake, or 

main shock, usually 

ACTIVITY ONE 

LEARNING THE DRILL 

RATIONALE 

Students who have rehearsed what to do in the event of an earthquake 

are more likely to stay calm and proceed rationally than students who 

have not. 

FOCUS QUESTIONS 

If an earthquake happened here, right now, what would you do? 

OBJECTIVES 

Students will: 

1. Describe and recognize the early signs of an earthquake. 

2. Drop, cover, and hold until a quake is over. 

3. Evacuate the school or other building in an orderly fashion. 

4. Describe procedures for coping with various earthquake hazards. 

originating in the same fault zone as 

the main shock. 

Foreshock: an earthquake that 

precedes a larger earthquake, or 

main shock, usually originating in the 

same fault zone as the main shock.

MATERIALS 

Q Materials to produce sound effects (optional) 

Q Standard first-aid manual 

PROCEDURE 

Teacher Preparation 

1. Choose an open area outside the school where your class would be 

safe in the aftermath of an earthquake. You may also want to let 

teachers in neighboring classrooms know that your class will be 

holding an earthquake and evacuation drill. 

2. Review basic emergency procedures in a standard first-aid manual, 

such as how to apply pressure for bleeding and how to handle injured 

people. 

AGU / FEMA 292 S EISMIC S LEUTHS
TEACHING CLUES AND CUES 

Most moderate-to-large 

earthquakes are 

followed, within the 

ensuing hours, days, 

A. Introduction 

Tell students that instead of a fire drill, they are going to have an 

earthquake drill. Impress them with the seriousness of this exercise; 

like a fire drill, it could literally save their lives. Explain that when 

they hear the signal Drop, cover, and hold, every student is to follow 

this procedure: 

Q Get under the table or desk. 

Q Turn away from the windows. 

Q Cover the back of your neck with one hand. 

Q Tuck your head down. 

Q Hold onto a leg of the table or desk, and move with it if it moves. 

Reinforce the list of actions by writing one word for each action on the 

board and asking students to repeat the three words Drop, Cover, and 

Hold. Remind them that earthquake shaking typically lasts less than a 

minute, so they will not be uncomfortable for long. 

B. Lesson Development 

1. Have several students demonstrate the drop, cover, and hold drill 

for the class, then have students practice it all together. 

2. Ask for a volunteer to describe the beginning of the earthquake, 

complete with sound effects, if the student chooses, and then to signal 

drop, cover, and hold. (Students will be familiar with earthquake 

sights and sounds by this time, so most of them should be prepared for 

this task.) Instruct the volunteer to begin talking at your signal, and to 

call out “Drop, cover, and hold” after just a moment or two of 

description. 

and months, by numerous smaller 

earthquakes (aftershocks) in the 

same vicinity. 

3. When the student signals, take cover, begin counting, and count 

slowly up to 60. (Remember, most earthquakes last less than a 

minute.) Then tell students that the earthquake is over, but they must 

be prepare for aftershocks. Ask them to evaluate their performance. 

4. If either you or the students believe the class could have done 

better, tell them an aftershock is beginning and repeat the procedure 

with a different volunteer. Emphasize the need for a quick response. 

5. When you are satisfied with the students’ response, tell them that 

the shaking has stopped and it is time to evacuate the building. Follow 

your normal fire drill route (or a safer route) to the outside of the 

building and lead the class to the spot you have chosen. 

6. When everyone is gathered outside, explain to the class that they 

will stay there for the rest of the period. It would not be safe to go 

back into the building until it has been inspected. Ask students to 

name some hazards they might have encountered along the way if an 

earthquake had occurred (fallen lockers or trophy cases, fires, smoke, 

fumes from laboratory chemicals or broken equipment, live electrical 

wires). Discuss procedures for dealing with these hazards. Then 

brainstorm responses to some other contingencies that might develop, 

AGU / FEMA 293 S EISMIC S LEUTHS
indoors or out. Ask students what they would do if. TEACHING CLUES AND CUES 

Q their normal evacuation route is blocked by wreckage? (Take time 

now to plan an alternate route with the class and be sure that 

everyone understands it.) 

This simulation may 

arouse feelings of fear or

anxiety for some 

students. Encourage 

Q an aftershock occurs while they are outside or en route? (drop and 

cover) 

Q a student or teacher is injured and can’t walk? (Don’t try to move 

the person unless there is immediate danger of fire or flooding. 

Instead, cover him or her with a sturdy table or whatever is 

available and send someone for medical help after the earthquake 

shaking stops.) 

Q someone is cut by shattered glass and is bleeding severely? (Apply 

pressure to stop the bleeding.) 

students to express their feelings 

freely and to be supportive of each 

other’s feelings. Emphasize that 

these reactions are normal and 

healthy, but that learning how to 

avoid injury will increase their 

chances of survival and those of 

everyone around them. Be aware 

that inappropriate optimism (“It can’t 

happen to me”) is just as unrealistic 

as extreme fear and anxiety. 

Q someone is hit by a falling lamp or brick? (If the person is 

conscious and able to walk, take him or her to a first-aid station as 

soon as possible. Even if the person appears to be unhurt, assign 

someone to stay close and watch for signs of dizziness or nausea.) 

Do not excuse students 

with special needs from 

participating in earthquake drills. It may not 

7. If any time remains in the class period, use it to review first-aid 

procedures and listen to the students’ feelings about the possibility of 

an earthquake or other natural disaster. Better yet, arrange for the 

school nurse or a Red Cross trainer to present this information. 

C. Conclusion 

The next day, back in the classroom, ask students to name some of the 

other places they might be when an earthquake occurs, and suggest 

safety procedures for each situation. Answers might include: 

Q Outdoors (Find an open place away from trees, buildings, power 

lines, and other structures. Kneel or sit until the shaking passes.) 

Q In a car (Stop as soon as possible, ideally in a level place away from 

buildings, power lines, bridges, and highway overpasses and 

underpasses. Passengers should stay in the car and hold on to doors 

and seats. The vehicle’s shock absorbers may cushion some of the 

shaking.) 

Q On the bus or subway (Stay calm and follow instructions from the 

driver or conductor.) 

be possible for students with 

impaired mobility to get under a desk 

or table. They can, however, learn to 

react quickly and turn away from 

windows, move away from light 

fixtures and unsecured bookcases, 

and use their arms or whatever is 

handy to protect their heads. 

Encourage other students to plan 

procedures to assist them with 

immediate protection and 

evacuation. 

Q In an open mall, a gymnasium, or other, indoor place with no 

shelter (Move to an inside wall. Kneel next to the wall, facing away 

from windows. Bend head close to knees, cover sides of head with 

elbows, and clasp hands behind the neck. If you are carrying a coat, 

a notebook, a package, or even a towel, hold it over your head for 

protection from debris or flying glass.) 

Conclude with time for questions and discussion. 

AGU / FEMA 294 S EISMIC S LEUTHS
ADAPTATIONS AND EXTENSIONS 

1. Some students may enjoy making an audiotape to use in step 2 of 

Lesson Development, above. 

2. Encourage students to take classes in first aid and cardiopulmonary 

resuscitation (CPR) from the Red Cross or other community 

organization, and to update training they already have. If a number of 

students are interested, arrange for a trainer to visit your class or 

provide presentations for the entire school. Students will gain 

confidence as well as competence. 

3. Invite the school’s health instructor or a representative from the Red 

Cross or other emergency agency to participate in the earthquake drill. 

4. Invite the class to join you in setting up a schoolwide earthquake 

drill. Invite the school administration and local emergency services 

officials with whom you established contact in Unit 1. 

5. If you repeat this drill in Unit 6 as part of the community 

earthquake simulation, vary it by putting up signs at one point along 

the evacuation route to indicate that the route is blocked. Lead the 

class out by the alternate route you planned in step 6, above. 

VOCABULARY 

ACTIVITY TWO 

RVS AT YOUR ADDRESS: RAPID VISUAL SCREENING OF SCHOOL 

AND HOME FOR EARTHQUAKE HAZARDS

Hazard: an object or 

situation that holds the 

possibility of injury or 

damage. 

RATIONALE 

Every teacher wants the classroom to be a safe environment for 

students. In this activity, you and your students will assess the safety 

of your classroom and make plans to remedy any earthquake hazards. 

Students will also assess their own homes. 

FOCUS QUESTIONS 

Can you imagine what your classroom would be like during an 

earthquake? 

How could you make your classroom and your school a safer place to 

be? 

How could you make your home safer? 

OBJECTIVES 

Students will: 

1. Distinguish between structural and nonstructural features of a 

building. 

2. Recognize nonstructural earthquake hazards in the classroom. 

3. Develop a rapid visual screening format to use in their homes. 

4. Devise methods to reduce earthquake hazards in school and at home. 

Nonstructural feature: an element 

of a building that is not essential to 

its structural design and does not 

contribute structural strength. 

Examples are windows, cornices, 

and parapets. 

Rapid visual screening (RVS): a 

method of assessing risk that relies 

on external observation. An observer 

who is trained in RVS can derive 

enough information from a quick 

visual assessment to know if closer 

examination is necessary. 

Retrofitting: making changes to a 

completed structure to meet needs 

that were not considered at the time 

it was build; in this case, to make it 

better able to withstand an 

earthquake. 

AGU / FEMA 295 S EISMIC S LEUTHS
MATERIALS 

Q Paper and pencils or pens 

Q Chalkboard and chalk or overhead projector and markers 

Q Student copies of Master 5.2a, RVS Checklist for the Classroom, 

one for each small group 

Q Student copies of master 5.2b, RVS Checklist for the Home 

PROCEDURE 

Teacher Preparation 

Write a brief letter telling parents that you are teaching a unit on 

earthquakes and encouraging their participation in a rapid visual 

screening of their home. 

Using the checklist on Master 5.2a, look around your classroom and 

note any items that could harm you and your students if an earthquake 

suddenly started to shake the room. Do not make any changes at this 

time unless you see a situation that needs immediate correction. 

TEACHING CLUES AND CUES 

If students made a 

shaking table in Unit 4, 

have volunteers demonstrate on the shaking 

A. Introduction 

1. Place several books on a desk. Have a student come up to the front 

of the room and shake the desk. Ask students to describe what they 

observed. 

2. Remind students that in earlier lessons they have demonstrated the 

importance of structural features in increasing building safety. Ask 

them to name some structural features. (girders, beams, floors, loadbearing walls, columns, foundations) 

3. Ask: Are these the only features of buildings that are affected by an 

earthquake? Explain that nonstructural features—outside brick walls 

that don’t bear weight, decorative overhangs, and panels added after 

construction; and inside cabinets, bookshelves, desktop computers, 

laboratory equipment, hanging light fixtures, wall decorations, 

aquariums, potted plants, and windows—can also injure people and 

damage property if they are not properly fastened to survive a strong 

earthquake. 

B. Lesson Development 

1. Ask students to quickly scan the classroom and each write down the 

name of at least one object or nonstructural feature that could be a 

hazard during earthquake shaking. Tell them they have just completed 

a rapid visual screening, or RVS. 

2. On the chalkboard or overhead projector, compile a list of the items 

students noted. Build a class discussion around the observations, 

asking students to specify why they considered particular items 

hazardous. 

3. Divide students into small groups and distribute copies of Master 

5.2a, RVS Checklist for the Classroom. Give students about 10 

minutes to complete the checklist. When they have finished, ask: Did 

table instead. 

AGU / FEMA 296 S EISMIC S LEUTHS
the list suggest any items we overlooked in our own assessment? If so, 

add these items to the class list. 

4. Ask students to share the methods they proposed to make the 

classroom safer during an earthquake. Many will be as simple as 

relocating or removing furnishings. Others may require tie downs, 

anchors, or fasteners to hold them in place during the shaking. 

Help the class reach consensus on a short list of changes to improve 

their own classroom for earthquake safety. 

5. Give students class time to develop an RVS checklist for their 

homes, based on their own screening of the classroom and Master 

5.2b. Assign students to screen their homes, with the cooperation of 

their families, and write brief reports of their findings, including 

suggestions for what they could do to make their homes safer during 

an earthquake. 

C. Conclusion 

Let colleagues know that your students are available to do hazard 

screenings of other classrooms. Assign teams of students to screen the 

classrooms of any interested teachers and develop plans to retrofit 

those classrooms for earthquake safety. 

ADAPTATIONS AND EXTENSIONS 

1. Encourage your students to present their data, analysis, and suggestions for retrofitting to the school’s principal, staff, or parent 

teacher organization and to their families. Both in school and at home, 

students may volunteer to do all or some of the work. 

2. Invite interested students to develop a one-minute radio or television 

spot to inform their community about rapid visual screening. V

AGU / FEMA 297 S EISMIC S LEUTHS
5.2a MASTER PAGE RVS list for the Classroom 

Name ___________________________________________________________ Date _____________________ 

Instructions 

1. Check yes or no for each of the following items. Skip any items that are not applicable to your classroom. 

2. Go back and circle all the nos. These are the items that you have identified as potentially dangerous to you and 

your classmates. 

3. For each no, suggest a way to remove the danger. (Use the comments space.) 

4. For each yes, explain why your team thinks the feature is earthquake resistant.

Yes No 

R R Are desks and tables located where they cannot slide and block exits? 

comments: 

R R Are large, heavy office machines secured to the wall or floor and located where they cannot slide, 

fall, or, block exits? 

comments: 

R R Are the tops of tall (4- or 5-drawer) file cabinets securely attached to the wall? 

comments: 

R R Do file cabinet doors have latches? 

comments: 

R R Are desktop computers securely fastened to work spaces? 

comments: 

R R Are bookshelves, cabinets, and coat closets secured to the wall and/or attached to each other? 

comments: 

R R Are display cases or aquariums protected against overturning or sliding off tables? 

comments: 

R R Is floor-supported, freestanding shop equipment secured against overturning or sliding? 

comments: 

R R Is freestanding equipment on wheels protected against rolling? 

comments: 

AGU / FEMA 298 S EISMIC S LEUTHS
MASTER PAGE 

Yes No 

R R Are all wall-mounted objects that weigh more than five pounds firmly anchored to the building’s 

structural framing? 

comments: 

R R Are all heavy, sharp, or breakable wall decorations securely mounted, with closed-eye hooks, for 

example? 

comments: 

R R Do books or materials stored on shelves have adequate restraints to keep them from flying off the 

shelves? 

comments: 

R R Are laboratory chemicals on shelves restrained? Are potentially hazardous chemicals stored 

securely? Are chemical storage areas vented, and located away from exits and corridors? Is there 

an up-to-date inventory of all chemicals stored? 

comments: 

R R Are the fluorescent light fixtures merely resting on the hung ceiling grid, or do they have other 

supports? 

comments: 

R R Are decorative ceiling panels or latticework securely attached? 

comments: 

R R Will hanging light fixtures swing freely without hitting each other if allowed to swing a minimum 

of 45 degrees? 

comments: 

R R Are fire extinguishers securely mounted? 

comments: 

R R If there are potted plants and other heavy items on top of file cabinets or in other overhead 

locations, are they restrained? 

comments: 

R R Do you see other hazards not included on this list? Specify. 

comments: 

AGU / FEMA 299 S EISMIC S LEUTHS
5.2b MASTER PAGE RVS list for the Home 

Name ___________________________________________________________ Date _____________________ 

R 1. Place beds so that they are not next to large windows. 

R 2. Place beds so that they are not below hanging lights. 

R 3. Place beds so that they are not below heavy mirrors. 

R 4. Place beds so that they are not below framed pictures. 

R 5. Place beds so that they are not below shelves with objects that can fall. 

R 6. Replace heavy lamps on bed tables with light, nonbreakable lamps. 

R 7. Change hanging plants from heavy pots into lighter pots. 

R 8. Use closed hooks on hanging plants, lamps, etc. 

R 9. Make sure hooks for hanging plants, lamps, etc. are attached to studs. 

R 10. Remove all heavy objects from high shelves. 

R 11. Remove all breakable things from high shelves. 

R 12. Replace latches, such as magnetic touch latches on cabinets, with latches that will hold during an 

earthquake. 

R 13. Take glass bottles out of medicine cabinets and put on lower shelves. 

(PARENT NOTE: If there are small children around, make sure you use childproof latches when 

you move things to lower shelves.) 

R 14. Remove glass containers that are around the bathtub. 

R 15. Move materials that can easily catch fire so they are not close to heat sources. 

R 16. Strap water heater to the studs of the nearest wall.* 

R 17. Move heavy objects away from exit routes in your house. 

R 18. Block wheeled objects so they cannot roll. 

R 19. Attach tall heavy furniture, such as bookshelves, to studs in walls. 

R 20. Use flexible connectors where gas lines meet appliances such as stoves, water heaters, and dryers. 

R 21. Attach heavy appliances such as refrigerators to studs in walls. 

R 22. Nail plywood to ceiling joists to protect people from chimney bricks that could fall through the 

ceiling. 

R 23. Make sure heavy mirrors are well fastened to walls. 

R 24. Make sure heavy pictures are well fastened to walls. 

R 25. Make sure air conditioners are well braced. 

R 26. Make sure all roof tiles are secure. 

R 27. Brace outside chimney. 

R 28. Bolt house to the foundation.* 

R 29. Remove dead or diseased tree limbs that could fall on the house. 

R 30. Install plywood reinforcements.* 

* See Master 5.3c, Strengthening Your Wood Frame House, for materials and instructions. 

AGU / FEMA 300 S EISMIC S LEUTHS
AGU / FEMA 301 S EISMIC S LEUTHS
Find and Fix the Hazards

(Wood Frame Homes)

AGU / FEMA 299 S EISMIC S LEUTHS

5.3 

TEACHING CLUES AND CUES 

If possible, prepare your 

students for this activity 

and the others in this 

lesson, then conduct 

one 

field trip that combines several of the 

activities. 

This activity emphasizes 

wood frame houses 

because they are 

common single-family 

RATIONALE 

Relatively simple modifications can greatly increase the safety of a 

wood frame house. Even students who do not currently live in such 

houses may at some future time. 

FOCUS QUESTIONS 

What are some structural earthquake hazards in a typical wood frame 

home? 

What can be done to reduce structural hazards in these homes? 

OBJECTIVES 

Students will: 

1. Assess risk factors in an existing wood frame house. 

2. Name several ways to strengthen an existing wood frame 

construction. 

MATERIALS

dwellings in many parts of the 

country. If you are not teaching all 

the lessons in this unit, be sure 

students understand that other types 

of structures also pose serious 

hazards. 

Q Classroom map of the local area, from Unit 1 

Q Master 2.5b, Soil and Geologic Maps and Map Sources (optional) 

Q Student copies of Master 5.3a, Structural Checklist 

Q Student copies of Master 5.b, Wood Stud Frame Construction 

Q Flashlights 

Q Goggles or other eye protection 

Q Head protection (helmet or hard hat) 

Q Clip board, paper, and pencil for notes 

Q Knee pads (optional) 

Q Student copies of Master 5.3c, Strengthening Your Wood Frame 

House 
PROCEDURE 

Teacher Preparation 

Contact a local realtor to find a nearby wood frame house that students 

can visit to conduct their assessment, or arrange with a contractor to 

visit a building site. If no vacant home is available, plan to use your 

own home or that of a friend or colleague. Arrange for transportation 

and permissions as necessary. 

A. Introduction 

Survey the class, asking: How many students live in wood frame 

houses? How many have friends or relatives who live in wood frame 

houses? How many have lived in such houses at some point in their 

lives? (Be sure students understand that the frame of the house may be 

wood even if the outside sheathing is stucco, decorative brick, brick 

veneer, stone, or some other material.) Record a count of student 

answers on the board. 

Tell the class that many homes in regions across the country are 

constructed of wood frame systems. These wooden structures are 

lightweight and flexible, and properly nailed joints are excellent for 

releasing earthquake energy and resisting ground shaking. 

Nevertheless, frame houses are sometimes damaged by an earthquake, 

causing a great deal of unnecessary trouble and expense for 

homeowners. This damage is unnecessary because most often it could 

have been prevented by some very basic alterations. It pays to find out 

if your home needs rehabilitation or strengthening and what can be 

done to lessen the earthquake hazard. 

B. Lesson Development 

1. Tell students that they are going to play the role of potential home 

buyers. Each of them has just landed a new job at a higher salary, and 

has decided to buy a new wood frame house. First, however, they 

must conduct a visual inspection of each home they consider buying to 

identify potential earthquake hazards. In this lesson they will learn 

what to look for in the foundation and other structural components. 

2. Ask: What seismic hazard designation has been applied to the area 

where we live? (In Unit 3, Lesson 3, you noted this information on the 

classroom local map. It is also available on Master 1.3b, U.S. 

Earthquake Hazard Map.) Explain that the degree of earthquake risk in 

any structure depends on where it is located as well as how it is built. 

If your school is located in a region identified on Master 1.3b as one 

of low seismic hazard, however, remind students that this map depicts 

what has happened; it does not predict what may happen. Earthquakes 

can occur anywhere in the world. Moreover, most Americans move 

several times in the course of their lives. 

3. If you did Lesson 2.5, students will also know the soil characteristics 

of their own region. If this information is not on your classroom map, 

refer students to local maps of soil characteristics, and 

AGU / FEMA 300 S EISMIC S LEUTHS
TEACHING CLUES AND CUES

Engineers and architects 

are the people best 

qualified to assess the 

strength of structures 

ask them to characterize the soil of the site they will be visiting. (See 

Master 2.5b, Soil and Geologic Maps and Map Sources.) Emphasize 

again that the site and the mode of construction interact. 

4. Distribute copies of Master 5.3a, Structural Checklist, and Master 

5.3b, Wood Stud Frame Construction. Point out the numbered areas 

on the drawing, and tell students that these are among the things they 

will be inspecting on their field trip. 

5. Travel with your class to the site you have chosen. Direct pairs or 

small groups of students to conduct inspections. When one group has 

finished, those students can complete their worksheets while the others 

proceed. 

C. Conclusion 

If you are in a moderate- or high-risk area, and your students find that 

their own homes could be reinforced to better withstand an 

earthquake, distribute copies of Master 5.3c, Strengthening Your 

Wood Frame House. Assign students to take home these simple 

directions for four inexpensive projects. High school students and their

parents can follow the steps on these pages to reinforce their wood 

frame homes. 

ADAPTATIONS AND EXTENSIONS 

If a majority of your students live in wood frame houses, you may 

assign this activity as an out-of-class exercise. Cover the information 

in the introduction with the whole class, then hand out copies of 

Master 5.3a, Structural Checklist. Ask students to assess the stability 

of their own homes and complete a report to share with their families 

and/or their classmates. Have students check on local building laws or 

talk to the city building inspector. Invite the building inspector to visit 

your class and talk about local building codes. V

Note: Master 5.3c, Strengthening Your Wood Frame House, is adapted from 

An Ounce of Prevention: Strengthening Your Wood Frame House for 

Earthquake Safety, with permission from the Bay Area Regional Earthquake 

Preparedness Project, 101 8th Street, Room 152, Oakland, CA 94607.

and their resistance to earthquakes. 

If your students have serious concerns, encourage them to discuss 

with their parents the possibility of 

bringing in a professional. Even the 

first modification on Master 5.3c is 

best undertaken after structural 

analysis, especially an analysis of 

foundation soils. 

AGU / FEMA 301 S EISMIC S LEUTHS
AGU / FEMA 302 S EISMIC S LEUTHS
5.3a MASTER PAGE Structural list 

Name ___________________________________________________________ Date ______________________ 

Instructions. Rate each component listed on a scale 

from 1 (good) to 5 (poor). 

1. The foundation must react as one unit for maximum 

earthquake resistance. The best foundations are steelreinforced concrete that reach down to bedrock. 

Examine the foundation. 

- Is it wood, brick, or concrete? 

- Is there any sign of steel reinforcement? 

- Are there holes or pits in the foundation? 

- Is the concrete powdery or crumbly? 

- Are there signs of water damage? 

- Are there visible cracks longer than 1 cm? 

Rating (Circle one): 1 2 3 4 5 

2. The wood plate (also known as a sill plate or a 

mudsill). This is the first structural wooden member 

placed on the foundation. Examine the wood plate. 

- Is it bolted to the foundation? 

- How far apart are the bolts? (The standard spacing 

is about four feet apart.) 

- Is the wood plate fasten or reinforced with metal 

plates? 

Rating (Circle one): 1 2 3 4 5 

3. Short stud walls (cripple walls) 

- Are they made of wood, brick, or another 

material? 

- Are they braced to resist earthquake-generated 

lateral forces? 

- Are they connected to the wood plates? 

- How is the floor frame fastened to the stud wall? 

Rating (Circle one): 1 2 3 4 5 

4. Exterior walls (shear walls) 

- What are the exterior walls made of? (brick, 

block, wood siding?) 

- Are they tied together? 

- If the walls are brick, block, or stone, what is the 

condition of the mortar? 

- Are they braced to resist earthquake-generated 

lateral forces? 

Rating (Circle one): 1 2 3 4 5 

5. Masonry fireplace chimneys. An unreinforced brick 

chimney is the weakest part of a house when 

earthquake shaking begins. 

- Does the house have one or more chimneys? 

- Is each chimney’s foundation part of the house? 

- What are the chimneys made of? 

- Are they reinforced and designed to be earthquake 

resistant? 

Rating (Circle one): 1 2 3 4 5 

6. Utilities and their mountings 

- Is the gas main mounted on flexible pipes? 

- Is the electrical service firmly mounted? 

- Is the main water shutoff accessible? 

Rating (Circle one): 1 2 3 4 5 

7. Exterior porches 

- Does the house have one or more porches? 

- Is the porch or porches attached to the house? 

How? 

- Is the foundation of the porch attached to the 

foundation of the house? 

Rating (Circle one): 1 2 3 4 5 

8. Make specific recommendations on how to correct 

any seismic deficiencies identified. 

AGU / FEMA 303 S EISMIC S LEUTHS
AGU / FEMA 304 S EISMIC S LEUTHS
5.3b MASTER PAGE Wood Stud Frame Construction

Reproduced from Rapid Visual Screening of Buildings for Potential Seismic Hazards: A Handbook, FEMA Earthquake 

Hazard Reduction Series 41.

AGU / FEMA 305 S EISMIC S LEUTHS
AGU / FEMA 306 S EISMIC S LEUTHS
MASTER PAGE Strengthening Your Wood 

Frame House: Four Projects 

5.3c 

adapted with permission of the Bay Area 

Regional Earthquake Preparedness Project 

Step 1: Steel Plate Bolting

Materials and Tools Needed

Q 1 cm (1/2 in.) diameter expansion bolts of a style acceptable to the 

local building department. Length of bolt determined by depth of 

hole, thickness of sill plate, and a projection of not less than 2.5 

cm (1 in.) above sill plate 

Q Masonry drill bit with carbide tip. Size determined by size and 

style of expansion bolt. 

Q Electric rotary impact drill or heavy-duty drill 

Q Short-handled sledge hammer or carpenter’s hammer for setting 

the bolts. 

Q 1 cm (3/8 in.) diameter plastic tubing 

Q Adjustable crescent wrench 

Q Chalk or lumber crayon 

Q Measuring tape 

Q Eye protection 

Q Noise protection 

Q Dust mask 

Installation Instructions for Step 1 

1. Lay out bolt locations. Bolts should be spaced at not more than 2 

m (6 ft) apart. Begin layout at not less than 10 cm (4 in.) or more 

than 30 cm (12 in.) from the end of any section of sill plate. 

2. Drill holes through the sill plate and into the foundation with a carbide drill bit of the size recommended for the style of expansion bolt 

used. Drill holes a minimum of 11.5 cm (4.5 in.) into foundation wall. 

3. After drilling a hole, clean out the concrete dust by inserting the plastic tubing into the hole and blowing out the dust. 

4. Place a cut washer over the bolt so it rests on top of the sill plate. Place the nut on the bolt and turn until the top of the nut is even with 

the top of the bolt. Insert expansion bolt into the hole until it stops. Using the sledge hammer or carpenter’s hammer, strike the top of the 

hole. 

5. Using a crescent wrench, tighten the nut until the sill plate begins to crush under the washer. 

AGU / FEMA 307 S EISMIC S LEUTHS
MASTER PAGE 

Step 2: Install Blocking at Sill Plate 

Note: This blocking is necessary only when the depth of the studs is different from the width of the sill plate, such as 2 x 4 studs attached 

to a 2 x 6 sill. If the stud depth and the sill plate width are the same, skip this step. 

Materials and Tools Needed 

Q Nominal 5 cm (2 in.) thick lumber (actually 4 cm, or 1.5 in. thick) the same depth as the studs 

Q 16d (16-penny) common nails 

Q Electric drill to pre-drill holes for nails, if necessary 

Q 0.2 cm (1/16 in.) diameter drill bits for pre-drilling nail holes and a bit at least 0.2 cm (1/16 in.) larger than the diameter (point-to-point 

distance across) of the anchor bolt nut 

Q Carpenter’s hammer 

Q Measuring tape 

Q Pencil 

Q Eye protection 

Q Dust mask 

Installation Instructions for Step 2 

1. Measure distance between studs. 

2. Cut pieces of blocking from 5 cm (2 in.) thick piece of lumber, the same depth as the studs, equal to the distance between studs, that the 

blocking fits snugly. 

3. In those stud spaces, where a new anchor bolt has been installed, mark the bolt location on the bottom of the blocking and drill a hole 

large enough that the blocking fits over the bolt and rests fully on the sill plate. 

4. Nail the blocking to the sill plate with between 3 and 6 16d nails. If blocking begins to split while the nail is driven, remove the nail and 

drill pilot holes for each nail with the 0.2 cm (1/16 in.) diameter drill bit. 

AGU / FEMA 308 S EISMIC S LEUTHS
MASTER PAGE 

Step 3: Install Plywood

Materials and Tools Needed

Q 1 cm (3/8 in.) or 1.2 cm (15/32 in.) thick plywood of Structural 1 

of CDX grade 

Q Nominal 5 cm (2 in.) thick lumber (actually 4 cm or 1.5 in. thick) 

the same depth as the studs. This will be used for blocking, if 

required. 

Note: The size of access to the average crawl space frequently 

doesn’t allow large pieces of plywood. You may need to use two or 

more smaller pieces of plywood. When multiple pieces are used to 

cover the height of the wall, blocking must be installed at the joint 

and completely nailed. If a single piece of plywood can be installed 

the full height of the reinforcing wall, blocking will not be necessary. 

Q 8d common nails for use with 1 cm (3/8 in.) plywood 

Q 10d common nails for use with 1.2 cm (15/32 in.) plywood 

Q 16d common nails for use with blocking, if required 

Q Electric circular saw 

Q Electric drill 

Q 0.2 cm (1/16 in.) diameter drill bit for pre-drilling nail holes if 

blocking is required 

Q Nail gun or carpenter’s hammer 

Q Measuring tape 

Q Chalk, lumber crayon or pencil 

Q 4 cm to 5 cm (1.5 in. to 2 in.) diameter hole saw 

Installation Instructions for Step 3 

1. If access to the crawl space under the house is such that full-width 

sheets, or sheets cut to the height of the cripple studs, will not fit, cut 

plywood sheets lengthwise to a width not less than 46 cm (18 in.). 

2. If sheets need to be cut, blocking will be necessary. Cut the 5 cm (2 in.) nominal thickness lumber to fit snugly between the studs. Nail 

each block to the studs with 2 16d nails at each end. Nails should be driven into the side of the stud. Pre-drilling for the nails will make this 

operation easier. Blocking should be installed at the same height for the full length of the plywood sheet. 

3. Starting at a comer, measure across the studs to find a stud where the sheets of plywood can butt. In order to do this, find the stud closest 

to, but not less than 1.2 m (4' ft.) or closest to, but not more than 2.4 m (8 ft.) from the corner. Measure the location of all ventilation vents 

and cut out holes in the plywood to match the vents. 

4. Mark the location of each stud at the top plate and on the foundation wall with chalk or lumber crayon. 

5. After cutting the plywood to fit, lay it up against the studs and hammer a nail in each comer of the plywood to hold it in place. Using a 

nail gun, or a carpenter’s hammer, place a nail every 10 cm (4 in.) around the perimeter of the plywood sheet. Then place a nail every 15 

cm (6 in.) along each stud. Use the nails appropriate for the thickness of the plywood. 

6. Once the plywood has been fully nailed, drill a 4 cm to 5 cm (1.5 in. to 2 in.) diameter hole above and below the blocking. 

AGU / FEMA 309 S EISMIC S LEUTHS
MASTER PAGE 

Step 4: Strap Water Heater

Materials and Tools Needed

QTwo 1.8 m (6 ft.) lengths of 4 cm (1.5 in.) 

gauge pre-drilled strap 

QOne 3.1 m (10 ft.) length of 1 cm (.5 in.) 

EMT tube (conduit) 

QFour 1 cm x 7.5 cm (5/16 in. x 3 in.) lag 

screws with washers 

QTwo 1 cm x 2 cm (5/16 in. x 3/4 in.) hex 

head machine bolts with 1 nut and 2 

washers each 

QTwo 1 cm x 3 cm (5/16 in. x 1-1/4 in.) 

hex head machine bolts with 1 nut and 2 

washers each 

QElectric drill 

QTape measure 

QHammer 

QHacksaw 

QCrescent wrench 

QVise or clamp 

QPower drill 

Q1 cm (3/8 in.) drill bit 

QCenter punch 

Installation Instructions for Step 4 

1. Mark water heater at 15 cm (6 in.) from 

top and about 46 cm (18 in.) up from 

bottom. Transfer these marks to the wall. 

Locate the studs in the wall on both sides of 

the water heater. 

2. Drill a 0.5 cm (3/16 in.) hole 7.5 cm (3 in.) deep through the wall sheathing and into the center of the wood studs at the four marks made 

in step 1. 

3. Measure around the water heater and add 7.5 cm (3 in.) to the measurement. Using a hacksaw, cut the two 4 cm (1.5 in.) 16-gauge metal 

straps to this length for encompassing water heater. 

4. Mark 4 cm (1.5 in.) from each end of metal straps, insert them in a vise, and bend the ends outward to approximately a right angle. Bend 

the straps into a curve. 

5. Measure the distance from a point midway on each side of the water heater to the hole drilled in the wan (probably two different 

lengths). Add 4 cm (1.5 in.) to these measurements. Using a hacksaw, cut two pieces of tube to each of these two lengths. 

6. Using a hammer, flatten approximately 4 cm (1.5 in.) at each end of the four pieces of tubing by laying the tube on a flat metal or 

concrete surface and striking with the hammer. Be sure you flatten both ends on the same plane. 

7. Insert the flattened ends of the tubes, one at a time, into a vise or clamp. With the hammer and center punch make a mark 2 cm (3/4") 

from each end at the center of the flattened area of the tube. Drill 1 cm (3/8 in.) holes in each end of all four tubes (8 holes). Be sure tubes 

are clamped down while drilling. Bend each end to about 45 degrees. 

8. Wrap the straps around the heater and insert a 1 cm x 3 cm (5.16 in. x 1.25 in.) bolt with washers into the bent ends. Tighten nuts with 

fingers. Insert 1 cm x 2 cm (5/16 in. x 3/4 in.) bolts through straps from the inside at the mid-point on each tube strut and insert on hole in 

the wall stud. You may need to tap the lag screw gently into the hole to start it, then tighten with crescent wrench. 

9. Adjust the straps to the proper height and tighten nuts snugly. If the nuts are too tight, the straps could tilt the heater.

Note: Flexible gas and water supply lines to the water heater will greatly reduce the danger of water pipe leaks and fire or explosion from 

a gas leak after an earthquake. If your water heater does not have a flexible gas line, contact a licensed plumber to install one. These 

instructions are for a 30 to 40 gallon water heater within 30.5 cm (12 in.) of a stud wall. 

AGU / FEMA 310 S EISMIC S LEUTHS
5.4 

Rapid Visual Screening (RVS) 

in the Community 

VOCABULARY 

Canopy: a covered area 

that extends from the 

wall of a building, 

protecting an entrance. 

RATIONALE 

Students will perform an informal RVS (rapid visual screening) to 

determine the nonstructural hazards to people and property that could 

be caused by buildings in their community during an earthquake. 

FOCUS QUESTIONS 

What buildings in my town or city might pose a serious risk of 

casualties, property damage, and/or severe curtailment of public 

services, if a damaging earthquake happened here? 

OBJECTIVES 

Students will: 

1. Conduct a sidewalk survey of nonstructural building hazards in 

their community. 

2. Record their observations on data collection forms. 

MATERIALS 

Q Transparency from Master 1.3b, U.S. Earthquake Hazard Map 

Q Classroom wall map of your own region which includes seismic 

hazard designations. This may have been prepared in Unit 1. 

Q Overhead projector (optional) 

Q Transparency made from Master 5.4a, Nonstructural Hazards 

Q Student copies of Master 5.4a, Nonstructural Hazards 

Q Student copies of Master 5.4b, RVS Observation Sheet, six for each

team 

Q Clipboard for holding observation sheets and drawing paper 

Q Pens or pencils 

Q Blank drawing paper 

Q Straightedge or ruler for drawing sketches 

Cantilever: a beam, girder, or other 

structural member which projects 

beyond its supporting wall or column. 

Cladding: an external covering or 

skin applied to a structure for 

aesthetic or protective purposes. 

Cornice: the exterior trim of a 

structure at the meeting of the roof 

and wall. 

Glazing: glass surface. 

Masonry veneer: a masonry (stone 

or brick) facing laid against a wall 

and not structurally bonded to the 

wall. 

Parapet: part of a wall which is 

entirely above the roof. 

Portico: a porch or covered walk 

consisting of a roof supported by 

columns. 

Veneer: an outside wall facing of 

brick, stone, or other facing materials 

that provides a decorative surface 

but is not load-bearing.

AGU / FEMA 311 S EISMIC S LEUTHS
Q Camera, preferably instant (optional; if available, replaces sketches) 

Q Tape or stapler, for affixing photo (optional) 

Q Red marking pen 

PROCEDURE 

Teacher Preparation 

Select site(s) for the class field assignments, choosing the nearest large 

concentration of buildings. Students may choose buildings to survey 

or they may be assigned. 

A. Introduction 

Tell students that they are going to assume the role of building 

inspectors in completing an informal sidewalk survey of buildings in 

their community. 

B. Lesson Development 

1. Ask students whether their region of the country is thought to be at 

low, moderate, or high risk for earthquakes. If you do not have this 

information on your classroom map, project the transparency made 

from Master 1.3b, U.S. Earthquake Hazard Map. If your school is 

located in a region pictured on the map as one low seismic hazard, 

remind students that they may not always live where they live now, 

and other natural disasters may affect the buildings. 

2. Tell students that a building may be structurally sound but its 

exterior decorations may create a hazard. These are called 

nonstructural hazards. Project the transparency made from Master 

5.4a, Non-structural Hazards, and elicit student descriptions of 

nonstructural hazards on the outside of buildings in the drawing. 

3. Tell students that for the purpose of this exercise, they will assume 

that a major earthquake is likely in their area in the next several years. 

They will take a walk and record their observations of nonstructural 

hazards. 

4. Assign each student a partner. Distribute six copies of Master 5.4b, 

RVS Observation Sheet, to each pair, and ask each pair of students to 

complete the following steps for six buildings, noting all the 

information on their observation sheets. 

a. Record a description of the building and its address or location. 

b. Note materials used in construction. 

c. Estimate the year of its construction. 

d. Record its size (number of floors, area, shape, and other 

information). 

e. Determine the current use (business, apartments or other). 

f. List the readily visible nonstructural hazards. 

g. Sketch or photograph the building. 

AGU / FEMA 312 S EISMIC S LEUTHS
5. Back in the classroom, suggest ways for students to fill in any missing information. Individuals may volunteer to call their mentors in the 

chamber of commerce, the local building department, or the public 

works department. Students could also call the firm that developed or 

manages a building. Then instruct all the students who filled out forms 

on the same building to compare their data and discuss any 

discrepancies. The goal of this process should be an assessment of 

each building surveyed that represents the students’ best consensus. 

C. Conclusion 

On the classroom local map you started in Unit 1, use a red marker to 

circle any block or group of blocks where concentrated nonstructural 

damage could be expected in the event of an earthquake. Open a class 

discussion of what students have learned. If students have not already 

expressed an opinion, ask if the sidewalks they traveled would be safe 

places to be during an earthquake. Generally, the most dangerous 

place to be is at building exits and directly adjacent to buildings (on 

the sidewalks, for example). 

ADAPTATIONS AND EXTENSIONS 

1. If a structural engineer is present or structural information is 

available from the building manager, students may also informally 

judge which buildings could be expected to withstand heavy earthquake shaking. 

2. If structural information is available from the building manager, 

students may also list the type of building construction used (wood, 

steel, masonry, cement, or other building materials.) V

AGU / FEMA 313 S EISMIC S LEUTHS
AGU / FEMA 314 S EISMIC S LEUTHS
5.4a MASTER PAGE Nonstructural Hazards

Name ___________________________________________________________ Date _____________________ 

AGU / FEMA 315 S EISMIC S LEUTHS
5.4a MASTER PAGE Nonstructural Hazards (key) 

Date: 

AGU / FEMA 316 S EISMIC S LEUTHS
5.4b MASTER PAGE RVS Observation Sheet

Name ___________________________________________________________ Date _____________________ 

1. Building name 

2. Street address 

3. Materials used in construction 

4. Year of construction 

5. Size (number of floors), area, and shape 

6. Current use 

7. List of nonstructural hazards (see Master 5.4a and vocabulary for illustrations and definitions) 

a. 

b. 

c. 

d. 

e. 

f. 

g. 

h. 

i. 

j. 

k. Sketch building or attach photo. 

l. 

m.

(Continue on back if necessary) 

AGU / FEMA 317 S EISMIC S LEUTHS
AGU / FEMA 318 S EISMIC S LEUTHS
Are the Lifelines Open? 

Critical Emergency Facilities and Lifeline 

Utility Systems

AGU / FEMA 319 S EISMIC S LEUTHS

5.5 

VOCABULARY 

Lifeline: a service that is 

vital to the life of a 

community. Major lifelines include transportaRATIONALE 

How well a community recovers from a damaging earthquake depends 

on the survival of critical emergency facilities and major utility 

systems (“lifelines”). In this lesson, students resume their focus on 

community preparedness. 

FOCUS QUESTIONS 

Where are the critical emergency facilities and major lifelines in my 

community, and how vulnerable are they? 

How would my community survive a damaging earthquake? 

OBJECTIVES 

Students will: 

1. Name and locate the critical emergency facilities and lifelines in 

their community, and evaluate their sites for geological hazards. 

2. Contact civic leaders, heads of emergency facilities, and public 

utility officials to learn about their emergency plans, or renew existing 

contacts. 

3. Report to the class and the community on what they have learned. 

MATERIALS

tion systems, communication 

systems, water supply lines, electric 

power lines, and petroleum or 

natural gas pipelines. 

Q Brainstorming list of survival necessities from Unit 1, Lesson 2 

Q Master 5.5a, Lifelines and Critical Emergency Facilities TEACHING CLUES AND CUES 

Q Back of Master 5.5a, Problem Areas 

Q Master 5.5b, A Chain of Disasters 

If your students have not 

developed a map of your 

own area that contains 

Q Local map(s) showing locations of major emergency facilities and 

lifeline systems 

Q Classroom local map developed in Lesson 1.3, with notes on soil 

conditions from Lesson 2.5 

Q Red marking pen 

Q Local telephone directories 

information on fault and soil types, 

use the maps on Master 2.5c to 

show them how this kind of 

information is presented visually. 
TEACHING CLUES AND CUES

If your community is in 

one of the parts of the 

country where earthquakes have not been 

recorded, students can learn about 

preparations for other kinds of 

natural hazards, such as floods, 

hurricanes, and tornadoes. In many 

cases the same systems would be 

affected and the some kinds of 

preparations will have been made. 

Fire departments will be an excellent 

source of emergency information. 

TEACHING CLUES AND CUES

Emphasize that every 

student is to make at 

least one phone call. 

Calling several people in 

PROCEDURE 

Teacher Preparation 

Read Master 5.5a, Lifelines and Critical Emergency Facilities. Decide 

how you will group students for this activity. If necessary, combine 

categories, such as natural gas and petroleum fuels, so that together the 

groups cover all the areas. For each group, make one copy of the local 

map(s) with locations of major emergency facilities and lifeline 

systems. Also make one copy of a local map showing geological hazards, if your classroom map does not already have this information. 

A. Introduction 

Display the list of necessities for survival that students developed in 

Unit 1, Lesson 1. Review the list with the class and ask if they have 

anything to add, or if anything they included at that time now seems 

less than essential. When the class has reached consensus, display 

Master 5.5a or distribute copies. Does the list include anything 

students have omitted? To reinforce the connections among the many 

kinds of damage earthquakes can cause, display Master 5.5b, A Chain 

of Disasters. Have students revise their list of necessities again to 

incorporate anything they may have missed. Emphasize the 

importance of emergency facilities—such as hospitals, fire stations, 

and police departments—and of public utilities—such as telephone 

lines, electric power systems, water supply systems, and transportation 

into and out of the affected area. 

B. Lesson Development 

1. Divide the class into small groups and assign one or more of the 10 

systems listed on Master 5.5a to each group. Individual student’s 

responsibilities will reflect their mentor’s areas. 

2. Distribute one set of maps to each group. Instruct students to 

compare the lifeline maps to the classroom local map and note any 

geological features in their service area that might constitute a hazard. 

Invite them to develop their own system for indicating relative degrees 

of risk on the lifeline maps: coding by color, by number, or by 

different kinds of symbols, for example. When they have worked out a 

system that satisfies everyone, students can transfer this information to 

the classroom map. 

3. Instruct students in each group to plan reports on the community’s 

plans for surviving the first 72 hours after an earthquake. They may 

need to renew their contacts with key people in their assigned service 

areas and schedule phone interviews. Give students class time to 

prepare lists of questions for their interviews. Then ask each group to 

exchange its list with another group and critique the questions. 

4. When every group’s questions have been reviewed and students are 

satisfied that they will elicit the necessary information, ask students to 

make the phone calls outside of class and take notes on what they 

learn. 

5. The next time the class meets, allow 10 minutes for students in each 

group to pool their information. Then invite a representative 

each system will increase the 

amount and quality of information 

students receive. Students are also 

likely to find what they learn 

reassuring—for example, that local 

hospitals have emergency backup 

generators. 

AGU / FEMA 320 S EISMIC S LEUTHS
from each group to report to the class on how the system that group 

studied would operate during an emergency. 

C. Conclusion 

On the classroom local map, use red ink to indicate any lifelines or 

critical facilities that may be at high risk in the event of an earthquake or other natural disaster. 

Discuss students’ reactions to what they have learned. If they are 

pleased with the community’s level of preparedness, overall or in any 

of the separate systems, encourage them to write letters of congratulation to the appropriate officials or to the newspaper. If they are 

concerned that preparation seems inadequate, or if they have concerns 

about siting and geological hazards, they may write letters expressing 

their concern and recommending improvements. 

Direct students to put their notes from this activity away in a safe 

place. They will need this information again in the Unit 6 role-playing 

activity. 

ADAPTATIONS AND EXTENSIONS 

1. If you know that your area is one of low seismicity, try to locate 

flooding maps, erosion maps, or maps of other types that are 

particularly relevant to your area. Have students learn about 100-year 

floods, the effect of windstorms over time, or other hazards that are 

specific to your community. 

2. Provide maps of the state or the region surrounding your local area. 

Challenge students to identify alternate emergency facility locations 

and alternate transportation routes and map them out for classroom 

display. V

AGU / FEMA 321 S EISMIC S LEUTHS
AGU / FEMA 322 S EISMIC S LEUTHS
MASTER PAGE 

Lifelines and Critical 

Emergency Facilities

5.5a 

A. Critical Emergency Facilities 

1. Medical facilities: hospitals, blood banks 

2. Emergency response facilities: police stations, fire departments 

3. Local office: emergency operations center 

B. Lifeline Utility Systems 

1. Transportation systems: highways, freeways, bridges, airports, railroads, docks and marinas

2. Communication systems: telephones, radio, television, newspapers 

3. Water supply: dams and reservoirs, aqueducts, distribution lines 

4. Waste water: treatment plants, holding tanks, collection lines, effluent lines 

5. Electric power: transmission towers and lines, switching stations, power generating plants, local distribution 

lines 

6. Natural gas: holding tanks, pipeline distribution lines 

7. Petroleum fuels: refineries, tank farms, pipelines 

AGU / FEMA 323 S EISMIC S LEUTHS
5.5a MASTER PAGE Problem Areas

Name ___________________________________________________________ Date: _____________________ 

1. If electricity is cut off, electric appliances will not function. Without refrigeration, large amounts of food and 

medicine will be liable to spoil. Gasoline pumps and auto service stations win be unable to pump gasoline. 

Without power, airport control towers will have to rely on backup systems. Airports may function at limited 

capacity or not at all. 

2. If water distribution systems fail, the community will have no clean drinking water. Water may be limited or 

unavailable for fighting fires. 

3. If hospitals are damaged, they will not be able to provide care and treatment for injuries and casualties. Even if 

a building’s structure survives, its services may be limited by lack of water and electricity and lack of 

transportation. Modern hospitals rely heavily on technology. 

4. Rupture of petroleum fuel or natural gas pipelines may cause serious fires in the community and outlying areas, 

as well as shortages of heat and power. 

5. If sewer systems fail, lack of sanitation may cause epidemics, such as cholera. 

AGU / FEMA 324 S EISMIC S LEUTHS
5.5b MASTER PAGE A Chain of Disasters

AGU / FEMA 325 S EISMIC S LEUTHS
AGU / FEMA 326 S EISMIC S LEUTHS
5 UNIT RESOURCES 

Books 

American Red Cross, Los Angeles Chapter. (1985). 

The Emergency Survival Handbook. In English and 

Spanish. A simple, practical, and easy-to-use guide; 

includes disaster planning, first aid, and survival skills. 

Bay Area Regional Earthquake Preparedness Project 

(BAREPP). (1990). An Ounce of Prevention: 

Strengthening Your Wood Frame House for 

Earthquake Safety. Oakland, CA: CA-OES, 

415-540-2713. 

Federal Emergency Management Agency (FEMA). 

(September 1986). “Family Earthquake Safety—Home

Hazard Hunt and Earthquake Drill.” FEMA 113. Tips 

on safe places and danger zones in the house, 

earthquake drills, and what should be done before and 

after. 

Federal Emergency Management Agency (FEMA). 

(1990). “Guidebook for Developing a School 

Earthquake Safety Program.” FEMA 88. Washington 

DC: FEMA Publications, 500 C St., SW, Washington, 

DC 20472. This 50-page guide covers earthquake 

hazard identification; drills; response, communication, 

& shelter planning. 

Federal Emergency Management Agency. (1993). 

“Identification & Reduction of Nonstructural Hazards 

in Schools.” FEMA 241. 

Federal Emergency Management Agency. (October 

1990). Non-Technical Explanation of the NEHRP 

Recommended Provisions. FEMA 99. Washington, 

DC: Intended to help individuals assess how earthquakes affect buildings & how enforcement of 

building codes helps to minimize loss. 

Federal Emergency Management Agency. (July 1988). 

Rapid Visual Screening of Buildings for Potential 

Seismic Hazards: A Handbook. FEMA 154. 

Washington, DC: FEMA Describes the technique of 

rapid visual screening of buildings for potential 

seismic hazard. 

Federal Emergency Management Agency. (1989). 

Seismic Considerations: Elementary and Secondary 

Schools. FEMA 149. Washington, DC: Building 

Seismic Safety Council. Covers the costs & benefits of 

applying seismic design in the construction of new 

school facilities. Explains how damage occurs to 

nonstructural components & building contents. 

Helfant, David Benaroya. (1989). Earthquake Safe: A 

Hazard Reduction Manual for Homes. Berkeley, CA: 

Builders Booksource. A little book with reasonable 

explanations, detailed procedures, and plentiful 

illustrations. 

Lagorio, Henry J. (1990). Earthquakes. New York: 

John Wiley and Sons, Inc. An architect’s guide to 

nonstructural seismic hazards. Focuses on site 

planning, building design, urban planning and design, 

rehabilitation of existing buildings, and disaster 

recovery and reconstruction. 

Matthys, Levy, and Salvadori, Mario. (1992). Why

Buildings Fall Down. New York and London: W.W. 

Norton and Company. 

Wesson, R.L., and Wallace, R.E. (1985). “Predicting 

the Next Great Earthquake in California.” Scientific 

American 252, 2: 35-43.

AGU / FEMA 327 S EISMIC S LEUTHS
UNIT RESOURCES 

Nonprint Media 

Microstation, V. 5. A computer-assisted drafting 

program for student use. Order from Intergraph 

Corporation, Huntsville, AL, 1-800-345-4856. 

$150 with educational discount. 

Reducing Nonstructural Earthquake Damage—A 

Practical Guide for Schools. Video (13:00 min). 

Schools & Earthquakes—Building Schools to 

Withstand Earthquakes. Video (14:27 min). Both 

available from FEMA. 

Note: Inclusion of materials in these resource listings does 

not constitute an endorsement by AGU or FEMA.

AGU / FEMA 328 S EISMIC S LEUTHS
UNIT SIX 
6 INTRODUCTION 

Now You Know It, Can You Show It? 

The concluding unit of this curriculum offers a 

variety of summing-up and assessment activities. 

Students will feel pride in their accomplishments 

after a pair of high-pressure simulations, a fastpaced quiz game, and finally, a reprise of the 

writing activity in Unit 1. The appendix to this unit 

provides materials from an intensive, communitywide simulation developed by Vermont teacher 

Sean Cox and adapted with his permission. You 

can use these materials to enrich your students’ 

experience of Lesson 6.2. 

Students who have developed relationships with 

people responsible for emergency preparedness 

will particularly enjoy the opportunity to role-play 

in the first two lessons. In the first they will enact 

a meeting of a crisis team charged with developing 

a comprehensive local earthquake preparedness 

plan. In the second, Earthquake Simulation, they 

will put that plan into practice. 

How much your students and your community 

benefit from Lesson 2, in particular, depends on 

how much you and they have invested in the 

curriculum up to this point. With the full 

involvement of community disaster officials and at a 

locale outside the school, this activity can be 

incredibly realistic and dramatic, as the experience of 

Sean Cox and his community makes clear. 

After the excitement of Lesson 2, students will 

welcome the purely intellectual stimulation of Lesson 

3, Test Your E.Q. I.Q. The questions are designed to 

test attitudes as well as information, and to reinforce 

knowledge by repetition. 

Both you and your students will be pleased to see 

how much information they can add to their Unit 1 

compositions in the final postassessment activity. 

This process reinforces essential writing and thinking 

skills. 

Now that students have completed this series of 

lessons, encourage them to continue to read and write 

about earthquakes and disaster preparedness. Some 

of the topics that have been introduced in these units 

may lead to science projects, college majors in 

related topics, and future careers. The information 

students have gained may even save their lives. 

AGU / FEMA 330 S EISMIC S LEUTHS
Preparing for the Worst: 

A Simulation

AGU / FEMA 331 S EISMIC S LEUTHS

6.1 

RATIONALE 

When natural disasters occur, many communities are totally unprepared because they lack a comprehensive emergency management 

program. Coordinated planning is essential if the stricken community 

is to return to a normal state of affairs. 

FOCUS QUESTIONS 

What kind of plans need to be in place to serve a community in the 

event of a natural disaster? 

OBJECTIVES 

Students will: 

1. Recognize the importance of advance planning for a community’s 

emergency response. 

2. Simulate the development of a community emergency plan for 

preparing for, responding to, and recovering from a natural disaster. 

MATERIALS

Q Transparency made from Master 6.1a, Edenton Map and Profile 

Q Transparency made from back of Master 6.1a, Edenton Map and 

Profile 

Q Overhead projector 

Q Student copies of Master 6.1a, Edenton Map and Profile (2 sides) 

Q Master 1.3a, Preparedness People (from Unit 1) 

Q Master 6.lb, Planning Roles (optional, for reference only) 

Q Self-adhesive name tags, one for each student 

Q Transparency made from Master 6.1c, Phases of an Effective 

Management Plan 

Q Transparency markers in four colors 
TEACHING CLUES AND CUES

In most parts of the 

country, there has not 

been any significant 

effort to coordinate 

PROCEDURE 

A. Introduction 

Begin by asking students what they would do if an earthquake struck 

the area where their school is located. Help them to recognize that the 

most important immediate response is not to panic and to seek cover 

as quickly as possible. The most available cover in the classroom is 

the protection offered by the desks and tables the students are using, 

so “drop, cover, and hold” is the first response. If you have not done 

so recently, conduct a drop-and-cover drill now, using the instructions 

in Unit 5, Lesson 2. 

Now expand the discussion to determine what students think would 

happen in their community if the earthquake was powerful enough to 

cause both loss of life and major property damage. 

community resources to respond to 

a major civic emergency like an 

earthquake. This planning scenario 

is intended to address an emergency 

resulting from an earthquake, but the 

process will yield procedures for 

dealing with other kinds of disasters 

as well. 

Q How would the community respond? 

Q Who would be in charge of managing the rescue operation? 

Q Who would be in charge of long-term recovery? 

Q What plans are already in place to assure that the emergency would 

be responsibly managed? 

B. Lesson Development 

1. Explain the purpose of the simulation and tell students that they will 

be playing the roles of community leaders charged with developing an 

outline for emergency management in the event of a disaster resulting 

from a natural or human-made hazard. They are meeting to develop a 

system to manage the effects of an emergency, preserve life and 

minimize damage, provide necessary assistance, and establish a 

recovery system in order to return the city to its normal state of affairs 

as quickly as possible. Their plan must define clearly who does what, 

when, where, and in what order to deal with the community crisis. 

Each student will adopt the role that she or he began learning about in 

Lesson 3 of Unit 1. For this activity, however, they are citizens of 

Edenton, a mid-size city located in an area of moderate risk for 

earthquake activity. In the late summer and fall, brush and forest fires 

also pose a threat to the community. Other disaster situations could 

develop from terrorism, civil disorder, a major transportation accident 

like a bus or train wreck, or an accident involving the release of 

hazardous materials. When the emergency exceeds the local 

government’s capability to respond, city officials may also call on 

state and federal governments for assistance. 

2. Project the back of Master 6.1a, Edenton Map and Profile, and go 

over the information with the class. Then project the map. Distribute 

copies of both sides for students’ reference. 

3. Direct students’ attention to the map of Edenton on Master 6.la. On 

the basis of the information provided, and other knowledge of the 

community they have gained from the profile, ask students to identify 

AGU / FEMA 332 S EISMIC S LEUTHS
TEACHING CLUES AND CUES

Be sure students understand that the lines they 

draw around these 

areas are only rough 

indica 

tions. In reality, each would be 

surrounded by a zone of influence, in 

which repercussions would also be 

felt. 

Students may choose 

whether to work in 

committees for part of 

the planning period or to 

all of the following. (The student who is playing the role of city 

manager will mark the transparency as indicated, using a different 

color for each type of information.) 

a. at least one area where you could expect landslides, liquefaction 

failures, and/or fault ruptures. (These areas should be outlined and 

numbered.) 

b. at least two groups of blocks where you could expect concentrated 

building damage. Include at least one commercial and one residential 

block group. (These areas should also be outlined and numbered, and 

may be referred to as Concentrated Damage Area 1,2,3, and so forth.) 

c. major facilities, such as hospitals, schools, government buildings, 

and high rise buildings that might be rendered at least temporarily 

unusable by an earthquake or other natural disaster. 

d. highway overpasses, roads, and other transportation facilities that 

might collapse or be left impassable by an earthquake. 

4. As a review, and to focus students on the roles they have been 

learning about, ask each to prepare a brief job description. Have 

students exchange their job descriptions with each other and ask and 

answer questions until they are clear about the functions and 

responsibilities of each. Master 6.lb contains some sample job 

descriptions for your reference. 

5. Once roles have been reviewed and job descriptions written, project 

Master 6.1c, Phases of an Effective Management Plan. Have the city 

manager convene the Edenton Emergency Management Planning 

Committee and call the meeting to order. 

6. Students will work together to develop a plan. The city manager, 

referring to the Phases transparency, will remind the group that every 

plan must have three parts: 

a. Before: preparations to be made before an emergency strikes, such 

as purchasing safety equipment, upgrading building codes, and 

educating the public. 

b. During: strategies for emergency response during an earthquake or 

other crisis. Lines of communication will be particularly critical in this 

phase. 

c. After: recovery plans for returning the community to conditions as 

normal as possible. 

7. When the group has completed its emergency management plan, 

provide time for students to report the details of their plan. Help them 

to evaluate their plan by asking these questions: 

remain in one group. 

QIs the plan realistic and timely? 

QIs it comprehensive? 

QIs it cost-effective? 

QDo we have the resources to implement it? If not, how might we 

obtain additional resources? 

AGU / FEMA 333 S EISMIC S LEUTHS
C. Conclusion 

Ask each student to augment her or his written job description with 

any particular responsibilities that will develop during a community 

crisis. Tell students that in the next activity they will have a chance to 

implement their plan. If questions arose in the planning process about 

how their city would function in an emergency, encourage students to 

contact their mentors before the next class meeting. V

AGU / FEMA 334 S EISMIC S LEUTHS
6.1a MASTER PAGE Edenton Map

AGU / FEMA 335 S EISMIC S LEUTHS
6.1a MASTER PAGE Edenton Profile

Edenton, the county seat of Belle County, has a population of 150,000. The county itself has 300,000 citizens. As 

Belle County’s only city, Edenton is the focal point of almost all services and activities. Its economy depends on a 

railroad repair facility operated by Amtrak and a large pharmaceutical manufacturing plant. These two operations 

are the city’s largest employers. Because of its pleasant climate year round, its easy accessibility by interstate 

highways from all parts of the state, and a landscape that invites hunting, fishing, hiking, cycling, and camping, 

tourism in recent years has become an increasingly important part of the local economy. 

Vital Statistics 

Population—150,000 

Schools 

8 elementary schools 

4 middle schools 

2 high schools 

1 community college 

Communications 

3 AM stations 

1 FM station 

1 television station 

1 daily newspaper (The Lark) 

Hospitals—2 (Mercy Hospital is a trauma center) 

Police Department—150 officers/20 civilian 

employees 

Fire Department—50 firefighters/10 civilian 

employees 

Recreational System 

8 city parks 

3 swimming pools 

4 fieldhouses 

1 golf course 

Houses of Worship—24 

Airport—1 (within city limits; single runway; 

provides jet service) 

Railroads—service by Amtrak 

Highways—2 interstates converge five miles north 

of the city 

Hotels—2 in center city, Motels—20, most in the 

areas served by the interstates 

Libraries—Main library with 8 neighborhood 

branches (all single-story buildings) 

Day Care Centers—10 licensed facilities 

Nursing Homes—4 

Retirement Communities—2 

Mobile Home Parks—3 

Shopping Malls—2 

Power Plants—1 (oil/gas) 

Water Supply—Aqueducts, pipelines, 2 pumping 

stations, 2 water treatment plants 

AGU / FEMA 336 S EISMIC S LEUTHS
6.1b MASTER PAGE Planning Roles

Chief of Police 

The police chief is responsible for protecting lives and 

property in the area he serves. Specific responsibilities 

include preserving the peace, preventing criminal acts, 

enforcing the law, and arresting violators. The chief is 

under oath to uphold the law 24 hours a day. He or she 

makes many of the final decisions dealing with budgets 

and services provided by the police force. 

Fire Chief 

This official is responsible for protecting lives and 

property from the hazards of fire. Responsibilities include 

fighting fires, rescuing trapped individuals, conducting 

safety inspections, and conducting fire drills and fire 

safety education. The fire chief also assists in other types 

of emergencies and disasters in community life. He or she 

makes many of the final decisions dealing with budgets 

and services provided by the fire department. The fire 

chief usually comes through the ranks, starting as a 

firefighter. 

Director of Public Works 

This official is responsible for the maintenance of 

systems built at public expense for the common good, 

such as highways and dams. In some communities these 

responsibilities may be dealt with separately by officials 

responsible for highway safety and community 

transportation services, water and sewage, and other 

areas; in some, they may be combined in one office. 

Director of Public Health 

This official, usually a physician, is responsible for 

controlling the spread of communicable disease in the 

community and for mitigating any threats to the public 

safety, such as the contamination of public water 

supplies. He or she also engages in proactive education 

and advocacy to encourage positive behaviors, such as 

proper nutrition, and discourage negative ones, such as 

smoking and the abuse of alcohol and other drugs. 

Coordinator of Community Transportation Services 

This official is responsible for the safety of public 

transportation and both public and private vehicles. He or 

she arranges for registration, licensing, and state 

inspections. The coordinator inspects public vehicles and 

coordinates operation and maintenance of equipment, 

storage facilities, and repair facilities. She or he directs 

the recording of expenses and controls, purchasing and 

repair spending. This official also helps plan and direct 

transportation safety activities.

Public Information Officer 

This official supervises a staff of public relations 

workers, directs publicity programs designed to inform 

the public, and directs information to appropriate groups. 

He or she clarifies the local government’s points of view 

on important issues to community or public interest 

groups and responds to requests for information from 

news media, special interest groups, and the general 

public. In an emergency, this function assumes added 

importance. 

Superintendent of Schools 

This official is responsible for managing the affairs of an 

entire public school district. He or she oversees and 

coordinates the activities of all the schools in the district 

in accordance with standards set by the board of 

education. Responsibilities include selecting and hiring 

staff, negotiating contracts with union employees, and 

settling labor disputes. He or she creates and implements 

plans and policies for educational programs, and, when 

necessary, interprets the school system’s programs and 

policies. The superintendent is also responsible for the 

development and administration of a budget, the 

maintenance of school buildings, and the purchase and 

distribution of school supplies and equipment, and 

oversees the school’s transportation system and health 

services. 

City Manager or Mayor 

This professional in public administration has general 

responsibility for the overall operation of the city. All 

department heads answer to this official, who serves as 

the city’s chief executive officer. A city manager is hired 

by the city council and serves at its discretion. A mayor is 

elected by the voters, but holds many of the same 

responsibilities. 

Members of the City Council (as needed) 

Each member determines the needs of the ward or district 

he or she represents by seeking out interviews, 

responding to constituents’ phone calls and letters, and 

referring persons to specific agencies for services. The 

member speaks before neighborhood groups to establish 

communication and rapport between the members of the 

community and the service agencies available. The 

members of the council also have the responsibility to 

help resolve problems facing the community at large, in 

such areas as housing, urban renewal, education, welfare, 

unemployment, disaster response, and crime prevention.

AGU / FEMA 337 S EISMIC S LEUTHS
AGU / FEMA 338 S EISMIC S LEUTHS
MASTER PAGE 

Phases of an Effective 

Management Plan

6.1c 

AGU / FEMA 339 S EISMIC S LEUTHS
AGU / FEMA 340 S EISMIC S LEUTHS
6.2 

Simulation:

Putting Plans Into Action 

RATIONALE 

Most emergency preparedness plans are never put into effect. In this 

activity students will have a chance to test the plans they have made, 

while also testing their own locality’s state of emergency 

preparedness. By the end of this session, students should have a good 

geographic sense of their community and some understanding of how 

the rest of the community will react to emergencies. 

FOCUS QUESTIONS 

How current, comprehensive, and effective are your community’s 

emergency preparedness plans? 

OBJECTIVES 

Students will: 

1. Understand how a community government works and how it 

responds to emergencies. 

2. Evaluate their locality’s earthquake emergency preparedness plans. 

3. Suggest changes in the existing emergency preparedness plan to 

reflect what has been learned. 

4. Develop a personal earthquake emergency response. 

MATERIALS 

Q Master 6.2a, Disaster Script 

Q Classroom community map (from Unit 1) 

PROCEDURE 

Teacher Preparation 

Secure the cooperation of at least some of the mentors who have been 

working with your students throughout this curriculum. If possible, 

arrange for a place outside of school, such as a city government 

building, where students can conduct this simulation. Work with the 

mentors to develop a disaster script, using Master 6.2a as a 

AGU / FEMA 341 S EISMIC S LEUTHS
AGU / FEMA 342 S EISMIC S LEUTHS

TEACHING CLUES AND CUES 

This activity can be as 

elaborate as you choose 

to make it. You may 

want to set aside a half 

day, or even a full day. 

The appendix that follows this unit is a report 

of an actual teacherplanned community 

beginning. Arrange to have at least one emergency preparedness 

official in attendance for this exercise and the debriefing that follows. 

If your class has developed the community map they began in Unit 1, 

they will have a strong sense of their own community’s physical and 

social arrangements. If not, you may want to work with the class to 

prepare a community profile similar to the Edenton Profile in Lesson 1 of 

this unit. 

A. Introduction 

Tell students that in this last unit of the Seismic Sleuths curriculum 

they will have a chance to draw on all that they have learned. Agree 

on a place to serve as the emergency command center. This may be a 

room at city hall, if you have made previous arrangements; your 

school auditorium, or a circle of chairs in the front of your own 

classroom. The community map will be the focal point of this area. 

B. Lesson Development 

1. Have the student who is playing the role of mayor or city manager 

convene a meeting of the preparedness council established in the last 

lesson. The purpose of this meeting is to discuss the budget of each 

department and clarify each administrator’s role in an emergency. 

Focus on the lines of communication and each person’s response to 

specific emergency situations (major fire, tornado, flood, earthquake, 

chemical plant disaster, etc.—focus on those most likely in your 

community). Whoever conducts the meeting will use the large 

community map to plot where each person’s main area of interest lies 

and what geographic areas are essential to maintaining the continuity 

of essential services, such as water treatment, sewage treatment, and 

electrical power. 

2. After 10 minutes or more, when the main points have been 

reviewed, but without warning, tell the students that an earthquake is 

occurring. Conduct a drop, cover, and hold drill, following the 

instructions in Unit 5, Lesson 2. Immediately after the drill, begin 

reading the script. Explain the time frame of the exercise. Students 

should then begin to take control of the situation and implement their 

emergency plans. 

C. Conclusion 

At the next class meeting, set aside some time for a debriefing and 

evaluation. Give students class time to write thank-you letters to their 

mentors and other members of the community who participated in this 

exercise and/or in earlier lessons. Mail the letters from school. 

earthquake preparedness drill. This 

is incorporated as a framework to 

use in constructing such an activity 

for your community. 

ADAPTATIONS AND EXTENSIONS 

1. Encourage students who have shown particular interest to maintain 

contact with their mentors, perhaps through volunteer work, a parttime job, or a request for career information. This association may 

inspire some students’ choice of a career. 

2. Write your own letters of appreciation to any community helpers 

who have not worked directly with individual students. With 

encouragement, some of these individuals may maintain an interest in 

the school and become valuable resources for students and faculty. V
6.2a MASTER PAGE Disaster Script

At 10:05 a.m. today, Tuesday, September 26, 1995, a magnitude 7.0 earthquake struck the community. At noon, 

the following damage had been reported: 

The downtown area was hardest hit. People have reported that most shelves, bookcases and display stands were 

knocked over. Masonry structures have sustained major damage, brick facades are collapsing, chimneys are 

falling, and some buildings have serious structural cracks. No fatalities have yet been reported. 

The hospital reports that its three-story gerontology unit has “pancaked,” causing the second and third floors to 

collapse on the first floor. At the time of collapse, 34 persons—29 patients and 5 staff members—were in that part 

of the building. Other parts of the hospital suffered nonstructural damage, some disruption to power, and an end to 

all but lifesaving procedures. The latest information indicates that the hospital will be at 50% operational capacity 

by 2:30 this afternoon. 

Of the three fire stations, two have stayed operational. The downtown station has been destroyed. Fire department 

personnel were able to move only one pumper wagon before the building collapsed on the ladder truck, 

ambulance, and emergency generator truck. 

This can be changed, embellished, tailored, and expanded for your community and your students. Additional 

effects that may be included:

• Large fire has broken out in downtown area 

• Water mains are cut 

• 20% of the population has sustained injuries 

• Utility lines are down 

• Animals in the zoo have escaped from their cages 

• Looters are rampaging through downtown 

• Sewers have backed up, endangering public health 

AGU / FEMA 343 S EISMIC S LEUTHS
AGU / FEMA 344 S EISMIC S LEUTHS
6.3 

What’s Your E.Q. I.Q.?

TEACHING CLUES AND CUES

Students may enjoy 

competing in the teams 

they established for the 

unit 4 activities (SETs). 

RATIONALE 

Students will review and solidify what they have learned in the 

preceding units by answering questions in cooperative teams. 

FOCUS QUESTIONS 

How well can students recall and apply what they have learned? 

OBJECTIVES 

Students will: 

1. Ask and answer questions about earthquakes and earthquake 

preparedness. 

2. Keep score. 

3. Learn from incorrect responses as well as correct ones. 

MATERIALS

Q Master 6.3a, Earthquake Review Questions 

Q Back of Master 6.3a, Answer Key 

Q Minute timer 

Q Chalkboard and chalk for recording the score 

Q Tag board and laminating materials (optional) 

PROCEDURE 

Teacher Preparation

Copy Master 6.3a and cut the pages apart into cards. You may want to 

back them on tag board and/or laminate them for durability. 

A. Introduction 

Divide the class into teams of four or five students each and give each 

team a number or a name. 

Give groups about 15 minutes to review the earthquake materials in 

their notebooks and ask each other questions as a warm-up. 

AGU / FEMA 345 S EISMIC S LEUTHS
TEACHING CLUES AND CUES

When all the cards have 

been used once, shuffle 

them and begin again. 

Repetition reinforces 

learning. 

B. Lesson Development 

1. Call two teams at a time to the front of the room. Instruct students to 

arrange chairs in two rows facing each other. Hand the deck of 

question cards to one team. For the first round, this team will ask and 

the other team will answer. 

2. Asking and answering both begin with the student on the left. The 

first asker reads a question out loud and starts the timer. The first 

student on the opposing team tries to answer it. If that student cannot 

answer the question, play passes to the second student on the same 

team, then to the third, if necessary, and so on until one minute is up. 

The questioning team keeps score, tallying one point for each correct 

answer. 

3. When any member of the team that is up answers incorrectly, play 

passes to the other team and the roles are reversed. When a member of 

the second team answers incorrectly, call two new teams to the front 

of the room. 

C. Conclusion 

When all the teams have had a chance to play, the team with the 

highest score may challenge any other team to a new round. If another 

team exceeds their score, they become the new challengers. The team 

with the highest score at the end of the period wins. 

ADAPTATIONS AND EXTENSIONS 

Invite students, to write questions and answers of their own to add to 

the deck. Be sure that all members of a group agree on the answer and 

the phrasing of the question before the card is put into play. V

AGU / FEMA 346 S EISMIC S LEUTHS
MASTER PAGE 

Review Questions

6.3a 

1. According to geologic studies, approximately how 

old is the Earth? 

[a] 2 thousand years 

[b] 7 thousand years 

[c] 2 million years 

[d] 4.54 billion years 

5. Although earthquakes occur almost everywhere, 

strong, damaging quakes are especially common in 

the: 

[a] Eastern United States 

[b] Pacific Ring of Fire 

[c] Mediterranean Region 

[d] Great African Rift 

2. All of the following people made major 

contributions to our knowledge of the Earth’s physical 

history and structure except: 

[a] Alfred Wegener 

[b] Inge Lehmann 

[c] Anna Maria Alberghetti 

[d] Andrija Mohoroviçic 

6. Which of these statements best describes the 

relationship between earthquakes and volcanoes? 

[a] Earthquakes cause volcanoes. 

[b] Volcanoes cause earthquakes. 

[c] Volcanoes and earthquakes both occur along the 

margins of Earth’s tectonic plates. 

[d] Volcanoes only occur in hot countries. 

3. Earthquakes are caused by: 

[a] strain energy that builds up and is suddenly 

released 

[b] tides 

[c] bad vibrations 

[d] the Richter scale 

7. Scientists can accurately predict earthquakes in the 

short range by studying: 

[a] the behavior of animals 

[b] changes in radon emissions 

[c] Rayleigh waves 

[d] none of the above 

4. Approximately how many earthquakes large enough 

to be rated significant by the U.S. Geological Survey 

occur worldwide during a calendar year? 

[a] More than 20 

[b] More than 100 

[c] More than 1000 

[d] More than 15,000 

8. The Richter scale measures an earthquake’s: 

[a] magnitude 

[b] amplitude 

[c] pulchritude 

[d] intensity 

AGU / FEMA 347 S EISMIC S LEUTHS
MASTER PAGE Answer Key

b d 

c c 

d a 

a d 

AGU / FEMA 348 S EISMIC S LEUTHS
MASTER PAGE 

9. How much greater is the amount of energy released 

by a magnitude 7 earthquake than the amount released 

by a magnitude 6 quake? 

[a] twice as great 

[b] 10 times as great 

[c] about 30 times as great 

[d] 100 times as great 

13. In which one of these states are strong and 

potentially damaging earthquakes relatively frequent? 

[a] Texas 

[b] Florida 

[c] Wisconsin 

[d] Alaska 

10. The method architects and structural engineers use 

to quickly assess a building’s earthquake resistance is 

called: 

[a] eyeballing 

[b] sedimentation 

[c] rapid visual screening 

[d] estimating 

14. If a strong earthquake struck while you were inside 

a building, what would you do to protect yourself? 

[a] run outside 

[b] dial 911 

[c] drop, cover, and hold 

[d] freeze 

11. The earthquake waves that are the first to arrive at 

the epicenter are called: 

[a] P waves 

[b] A waves 

[c] First waves 

[d] Love waves 

15. How much damage a building suffers in an 

earthquake depends upon: 

[a] how close it is to the fault 

[b] what it is build of and how it is built 

[c] what kind of soil it is built on 

[d] all three 

12. About how long does the violent shaking last in a 

typical earthquake? 

[a] 20 seconds 

[b] one minute 

[c] five minutes 

[d] 30 minutes 

16. To make a room safer in an earthquake, you 

would: 

[a] fasten all unsecured heavy objects 

[b] remove all pets 

[c] turn on the radio 

[d] lock the doors and windows 

AGU / FEMA 349 S EISMIC S LEUTHS
MASTER PAGE Answer Key

d c 

c c 

d a 

a a 

AGU / FEMA 350 S EISMIC S LEUTHS
MASTER PAGE 

17. A break in the Earth’s crust along which 

earthquake movement has occurred is called: 

[a] a gap 

[b] a fault 

[c] an epicenter 

[d] an isoseismal 

20. All of the following are good sources of 

earthquake information except: 

[a] United States Geological Survey 

[b] The National Enquirer 

[c] Federal Emergency Management Agency 

[d] National Earthquake Prediction Evaluation Council 

18. A gigantic ocean wave caused by an earthquake is 

called: 

[a] a samurai 

[b] a sand boil 

[c] a tsunami 

[d] a surface wave 

21. Resonance is buildup of amplitude in a physical 

system that occurs when the frequency of an applied 

oscillatory force is close to the natural frequency of 

the system. 

[a] true 

[b] false 

[c] sometimes 

[d] don’t know 

19. All of the following are structural elements except: 

[a] windows 

[b] bearing walls 

[c] braces 

[d] horizontal beams 

AGU / FEMA 351 S EISMIC S LEUTHS
MASTER PAGE Answer Key

b b 

a c 

a 

AGU / FEMA 352 S EISMIC S LEUTHS
6.4 

HEY, at Me Now!

RATIONALE 

This activity is designed to serve students and teachers as a gauge of 

what they have learned from this curriculum. 

FOCUS QUESTIONS 

What have you learned about earthquakes and earthquake 

preparedness? 

What will you do differently as a result of these lessons? 

OBJECTIVES 

Students will correct, elaborate, and refine their earlier writings by 

applying information they have gained from this curriculum. 

MATERIALS

Q Writing paper and pens or computers and printers 

PROCEDURE 

A. Introduction 

Explain that in this postassessment activity each student is to complete 

the same task he or she did in the preassessment activity. In rewriting 

each of the three passages, however, students are urged to draw upon 

what they have learned from the unit. Remind the students to focus on 

how their new knowledge has changed their way of thinking about 

earthquakes and earthquake preparedness. 

B. Lesson Development 

As they did in Unit 1, students will invent a specific quake. Each of 

their three accounts will describe the same earthquake, but the styles 

of the three will vary. 

New Reporter—a short, concise article describing the who, what, 

where, why, and when of the earthquake. 

Scientist—a scientific account stating what is objectively known about 

the earthquake: its causes, its Modified Mercalli and Richter ratings, 

and the possibility of aftershocks or more large earthquakes. 

AGU / FEMA 353 S EISMIC S LEUTHS
Eyewitness—a personal letter to a friend telling about being in an 

earthquake. This will describe what happened during the earthquake to 

the student, the building in which the student was, family members 

and pets, and the family home. Describe what you had done before the 

earthquake to be prepared, how effective your preparations were, and 

what you would do differently in preparation for the next earthquake. 

Also describe what life was like in the two weeks following the 

earthquake. 

C. Conclusion 

After collecting the papers, pair each student’s postassessment 

writings with the same student’s preassessment writings, and hand 

them out to a different student. Assign students the task of reading 

both sets and commenting on what the writer has learned from the 

unit. Follow with a class discussion of these comparisons, either the 

same day or the next. V

AGU / FEMA 354 S EISMIC S LEUTHS
6 UNIT RESOURCES 

Books 

Davis, James F.; Bennett, John H.; Borchardt, 

Glenn A.; Kahle, James E.; Rice, Salem J.; and Silva, 

Michael A. (1982). Earthquake Planning Scenario for 

a Magnitude 8.3 Earthquake on the San Andreas Fault 

in the San Francisco Bay Area. San Francisco: 

California Department of Conservation, Division of 

Mines and Geology. Although the maps and much of 

the discussion are specific to California, the sections 

on transportation, communications, water and waste, 

electrical power, natural gas, and petroleum fuels 

would be helpful for planning in other areas. 

Federal Emergency Management Agency. Central

City: A Model Community. Integrated Emergency 

Management Course. Emmitsburg, MD: Federal 

Emergency Management Agency, 1988. (SM 171.1) 

Plafker, G., and Galloway, J.P., eds. (1990). Lessons 

Learned from the Loma Prieta, California, 

Earthquake of October 17, 1989. (U.S. Geological 

Survey Circular 1045). Reston, VA: U.S. Geological 

Survey, 703-648-6891. 

Steinbrugge, Karl V.; Bennett, John H.; Lagorio, 

Henry J.; Davis, James F.; Borchardt, Glenn A.; 

and Topozada, Tousson R. (1987). Earthquake 

Planning Scenario for a Magnitude 7.5 Earthquake on 

the Hayward Fault in the San Francisco Bay Area. 

San Francisco: California Department of Conservation, 

Division of Mines and Geology. Although the maps 

and much of the discussion are specific to California, 

the sections on hospitals, schools, transportation, 

communications, water and waste, electrical power, 

natural gas, and petroleum fuels would be helpful for 

planning in other areas. 

Watson, R.W.; Poda, J.H.; Miller, C.T.; Rice, E.S.; and 

West, G. (1990) Containing Crisis: A Guide to 

Managing School Emergencies. Bloomington, IN: 

National Educational Service. 

Non-Print Media 

Silent Quake: Preparedness for the Hearing-Impaired. 

A videotape using American sign language, 

captioning, and voice-overs. Developed by the 

American Red Cross, Los Angeles, CA, available on 

loan from BAREPP, Oakland, CA; 415327-6017. 

Note: Inclusion of materials in these resource listings does 

not constitute an endorsement by AGU or FEMA. 

AGU / FEMA 355 S EISMIC S LEUTHS
APPENDIX 

 Drill: 

A Critical Skills Exercise

by Sean P. Cox, Teacher 

Salem High School, Salem, New Hampshire 

AGU / FEMA 356 S EISMIC S LEUTHS
APPENDIX 

Abstract 

Earth science students at Salem High School have participated in an environment of critical skills. Events are student 

centered, learning stresses both process and curriculum content, and the foundation for activity is problem-solving projects. 

This particular project had students designing and rehearsing part of an emergency management plan in response to a 

hypothetical earthquake affecting Salem, NH. Students assumed the roles of town officials in a three-hour drill held in 

Salem’s Emergency Operations Center (EOC). The drill was sponsored by the town of Salem and the New Hampshire Office 

of Emergency Management. Project origin, planning, performance, and follow-up are detailed in this paper. 

Introduction 

For seven months students in this class spent more than 100 hours not only learning about specific topics in Earth science but 

also learning specific strategies for learning and working together. In March, as our plate tectonics unit progressed, the time

to apply our learning had arrived. A project was designed in cooperation with our town’s emergency management director 

and the New Hampshire Office of Emergency Management. 

In this project students were to design, document, and use a hazard plan to be added to Salem’s Emergency Management 

Plan for earthquake response. Students did extensive research and documentation, preparing a plan and also preparing 

themselves to play roles as decision makers in a disaster. The teacher, the emergency management director, and Office of 

Emergency Management staff members met and communicated many times to finalize the details. 

The actual drill, held in Salem’s Emergency Operations Center (EOC), greatly surpassed all expectations. Students handled 

crisis after crisis as part of a three-hour drill that included mass destruction, dam failure, utility outages, looting, hospital 

closings, and multiple evacuations. Groups of students rotated through three one-hour shifts filling various roles in turn, 

including those of the school superintendent, reporters, and selectmen. There was confusion and near hysteria as a myriad of 

details crowded the EOC. Students struggled at times to prioritize and solve problems. All the participants and observers 

came away with a new respect for each other and a new appreciation of the need to be prepared for the worst. 

How It All Began 

Teaching in this class proceeds from the philosophy that learning is a very complex behavior. Learning is different for each 

individual, and schools need to recognize these differences. Schools also need to teach not only the “what” but also the 

“how” of learning. With this in mind, these 96 people were provided a student-centered environment that made them 

ultimately responsible for their learning both as individuals and as a group. Students spent many class periods doing 

activities that provided experience with various learning styles. Projects were used to create concrete and abstract 

opportunities for learners, including reading, writing, coordinating, prioritizing, and communicating. 

Emphasis is placed on the belief that there are often many viable solutions to a problem. For this reason, creativity is strongly 

fostered, as students are urged to produce quality work from their own base of knowledge and experience. The teacher is not 

the “fountain of knowledge.” Students must find their own answers that they can support fiercely and intimately. Guidance 

and direction are given in the form of specific teacher questions. As students gain experience and comfort completing 

curriculum-based projects in this student-centered class, they begin to take more control of their education, needing less 

teacher input. With greater student responsibility, the teacher’s goal is to balance content and process so that each remains 

equally valued in learning. 

AGU / FEMA 357 S EISMIC S LEUTHS
UNIT RESOURCES 

Earthquake in Salem, NH 

AGU / FEMA 358 S EISMIC S LEUTHS

So why dabble with earthquakes, not to mention the town’s Emergency Management Plan? Because high school students are 

interested in earthquakes. Earthquakes are unpredictable, damaging, and loud—characteristics admired and even shared by 

many teenagers. Moreover, the teachers saw a need for earthquake education, preparedness, and response within the 

community. 

In preparation for this major project, classes throughout the year dealt with process strategies and critical skills. Skills 

including decision making, problem solving, communication, cooperation, and documentation were addressed, rehearsed, 

refined, and incorporated into our classes. Additionally, students carried out many short-term projects in the field of plate 

tectonics and seismology. Specifically, students researched, modeled, and demonstrated types of seismic waves, seismic 

forecasting, hazard assessment, and New England’s seismic history. 

The next step in the project involved a contact with the person in Salem responsible for emergency management. The teacher 

had to determine if the anticipated needs existed and whether or not direct community involvement was possible. Salem’s 

fire chief, who also serves as its emergency management director, acknowledged a void in the town’s disaster response and 

was completely open to student input and community cooperation. As the teacher and the director discussed their needs, the 

project evolved into what they hoped would be a truly meaningful experience. Ninety-six of Salem’s teenagers might 

permanently and positively affect their community. 

The teacher expressed the following goals: 

A. Students will develop and implement a solution with an educational component to a real problem in our community. They 

will: 

 1. do community-based research 

 2. incorporate many information-gathering techniques 

 3. use a maximum number of resources 

 4. use preexisting models and/or plans where appropriate 

B. Students will select, implement, and refine certain process skills, such as decision making, problem solving, 

communication, cooperation, and documentation. 

C. Students will be able to describe all major theories on plate tectonics as well as how those theories relate to earthquakes.

D. Students will be able to describe New England’s earthquake history and its susceptibility to future seismic activity. 

E. The adults will empower students to come up with their own plan in an open environment with a minimum of restrictions. 

Planning, Planning, and More Planning 

The director suggested a drill that would test the students’ solutions as a way of summing up and evaluating the project. This 

drill would not only satisfy the teacher’s desire to test students, but also provide a rehearsal of the town’s Emergency 

Management Plan. The teacher and the director outlined the town’s need for a hazard plan and discussed the specific ways in 

which students might meet that need. A time and date for the drill were set, and a letter to the students was drafted, 

recognizing their recent experiences in these areas and requesting their aid. 

The next task was kicking off this 15-day extravaganza by arranging for expert speakers to come into the school. Issues 

discussed included seismology, engineering, hazard assessment, emergency response planning, and plan implementation. All 

of our guest experts graciously supplied printed materials to supplement their presentations. 

On kick-off day, the educators and the experts decided students needed additional guidelines to properly design a hazard 

plan. The design of the plan was separated into five areas—communication, evacuation, hazard assessment, private 

resources, and public resources. As the first few days passed, students struggled to prioritize the components of the problem 

and divide up responsibilities. The teacher carefully guided students by questioning them and challenging them to use skills 

and knowledge they had already developed. 

Meanwhile, the director scripted the drill, provided the teacher with the roles and titles students would assume during the 

drill (see list below), and secured access to a wide variety of resources. The resources included a college text, Federal 

Emergency Management Agency (FEMA) pamphlets, and a blank hazard plan illustrating plan design. Also made available 

were the telephone numbers of the town’s department heads and of state and regional emergency management personnel, 

and lastly, the most precious resource of all, personal attention and dedication. The New Hampshire Office of Emergency 

Management and its natural hazards program specialist also provided generous amounts of both time and materials. 
UNIT RESOURCES 

EOC Town Officials and Staff Roles 

TOWN OFFICIALS EOC STAFF 

Chairman, Board of Selectmen Message Loggers (2) 

Members, Board of Selectmen (4) Message Runners (2) 

Town Manager Updater, Status Board (1) 

Emergency Management Director Radio Communications (2) 

Fire Chief EOC Security (2) 

Police Chief EOC Logistics (2) 

Public Works Director Public Information Officer 

Health Officer Reporters (3) 

Chief Building Inspector 

Director of Human Resources 

(Welfare) 

American Red Cross Director 

Superintendent of Schools 

As the project continued, the teacher noticed an ever-increasing level of student anxiety and misdirection. Therefore, the 

teacher and the director arranged for a debriefing of the project’s progress. The students presented their ideas and findings to 

a panel consisting of the director, educators, and the New Hampshire natural hazards specialist. The panel was able to give 

students valuable feedback on their plan’s strengths and weaknesses. This day-long debriefing also allowed students a 

chance to look at the project from a critical point of view, breathing new life into their design and implementation efforts. 

At the beginning of the second week, the teacher finalized student sign-up for the roles they were to assume in a three-shift 

rotation. Each student selected (1) a decision making role, where he or she would play an active part in the Emergency 

Operations Center (EOC), and (2) an EOC staff role or a role with rescue equipment and media presentations. Each student 

also had to identify one shift during which to start a journal, recording not only observations of the drill’s varied actions and 

reactions, but also an introspective analysis of the project’s progression from start to finish. 

The director coordinated the attendance of the town’s department heads, the school superintendent, the American Red Cross 

representative, a utility company representative, and the media, as well as state and regional emergency management 

officials. The director and the teacher finalized details and made arrangements for physically disabled and motivationally 

disabled students, school and community rules implementation, lunch, and debriefing. 

It’s D-Day! 

At 8:30 a.m. on D-Day (Drill Day), students anxiously gathered materials and boarded the bus to Salem’s EOC, not knowing 

quite what to expect. Upon arrival at the Main Street fire station housing the EOC, students heard building rules and 

consequences, dropped off their coats, and positioned themselves for the first shift of the drill. With Salem’s youth in place 

as fire and police chiefs, building inspector, school superintendent, radio operator, message runners, EOC security, and 

newspaper reporters, the EOC opened and the drill began. 

The script for the day explained that the EOC had been opened in response to an earthquake at 7:50 a.m., measuring 7.5 on 

the Richter scale and centered in nearby Hudson, NH. With Salem’s adult department heads as advisors, students enacted 

their plan, prioritizing needs, communicating with counterparts, and solving problems, all while using the town’s minimal 

remaining resources as judiciously as possible. 

An excerpt from the drill script details the crisis students were reacting to. 

AGU / FEMA 359 S EISMIC S LEUTHS
UNIT RESOURCES 

SHIFT CHANGE—STATUS REPORT 

It is now 8:00 am (the second morning). 

During the night, the public works department began repairs on the known broken water mains. The water towers are back 

up to capacity, but water service is provided to only a small portion of the town (Main St./Depot area and Lawrence 

Rd./Cluff Rd. area). 

The sewer system is completely out of service and sewerage is beginning to leak into some streams and onto roads. All 

power in town went out for most of the night and is beginning to come on in sections. Cable TV is still out. The cracks in the 

dam at Arlington Pond appear to be worsening. 

The evacuation center has housed approximately 200 people who are in need of food. 

The Police Department spent a long night dispersing looters and making arrests. Approximately 20 people are in custody. 

The Fire Department responded to several building collapses, two house fires, numerous downed power lines, and 15 

ambulance calls. Most of the patients were taken to a temporary first aid station. 

Two relatively minor aftershocks were felt during the night. 

Decisions are made, aid is rendered, and nerves are wracked as each shift struggles with a seemingly endless onslaught of 

high-priority problems. At times, the EOC becomes a jumble of noise and confusion. Internal communication deteriorates 

and priorities temporarily blur. Selectmen try to solicit information from the building inspector, only to find him tied up with 

both the public works director and the health official. Finally, the emergency management director shouts for order, quieting 

the din and returning the EOC to a semblance of organization. After 180 minutes, simulating 24 hours of emergency 

responses highlighted by a telephone call from the Director of FEMA, Mr. Stickney, the drill concludes with a press 

conference. 

As we await the arrival of lunch, all participants are relieved, excited, exhausted, and slightly saddened to know the project 

has reached its end. Students share the disasters and the responses of each shift. Some write feverishly in their journals, not

wanting to forget a single moment. As the 30 pizzas arrive, students and staff alike enjoy a carefree lunch and conversation. 

With lunch cleared away, the group assembles for the anticipated critique and debriefing. Town and state emergency 

management officials have many kind words for the students, followed by praise from Salem’s emergency management 

director and the teacher. In spite of the positive input, students decide that their hazard plan can be improved, and request 

permission to keep the document for that purpose. 

At 1:15 p.m., the students, document in hand, say their good-byes and their thanks as the teachers and directors shake hands. 

After a short ride, the once and future emergency managers are back in school, heading off to their last-period class. These 

96 young teens have had the experience of a lifetime, gaining a priceless perspective on their community and themselves. 

Project Strengths and Weaknesses 

The success of the project far exceeded all expectations. Students were able to not only synthesize a plan for dealing with a 

natural disaster, but also put their plan into action. There were some areas of concern, however. 

Even though the plan allotted 15 decision-making roles, representing town officials, and another 15 staff roles in the EOC, 

there were, several students who had to double up in order to participate in the EOC’s operation. The EOC was always 

overcrowded with students, adult advisors, state and regional observers, and media. 

The strengths were numerous. This activity was truly student centered. Students took the initiative in researching and 

preparing the plan, several times even meeting after school and on weekends. Additionally, students had to make dozens of 

community contacts to gather materials and information. There was a rush of positive public relations for both the school and 

the town of Salem. Print media from Lawrence, MA, and Salem, NH, as well as TV news from Manchester, NH, covered the 

drill. Most satisfying to the teacher, the students ended the experience still wanting to do more, as they communicated 

through their lengthy and detailed journals. 

AGU / FEMA 360 S EISMIC S LEUTHS
Aftershock—an earthquake that follows a larger 

earthquake, or main shock, usually originating along 

the same fault as the main shock. 

Amplitude—a measurement of the energy of a wave. 

Amplitude is the displacement of the medium from 

zero or the height of a wave crest or trough from a 

zero point. 

Body waves—waves that move through the body 

(rather than the surface) of the Earth. P waves and S 

waves are body waves. 

Braces or Bracing—structural elements built into a 

wall to add strength. These may be made of various 

materials and connected to the building and each other 

in various ways. Their ability to withstand stress 

depends on the characteristics of the materials and 

how they are connected. 

Canopy—a covered area that extends from the wall of 

a building, protecting an entrance. 

Cantilever—a beam, girder, or other structural 

member which projects beyond its supporting wall or 

column. 

Cartographer—a map maker. 

Cladding—an external covering or skin applied to a 

structure for aesthetic or protective purposes. 

Cornice—the exterior trim of a structure at the 

meeting of the roof and wall. 

Compression—squeezing, being made to occupy less 

space. P waves are called compressional waves 

because they consist of alternating compressions and 

dilations, or expansions. 

Consolidated—tightly packed, composed of particles 

that are not easily separated. 

Continental drift—the theory, first advanced by 

Alfred Wegener, that Earth’s continents were 

originally one land mass, pieces of which split off and 

gradually migrated to form the continents we know. 

Diagonal braces—structural elements that connect 

diagonal joints. These braces may be made of solid 

materials or flexible materials. How they function 

depends on what they are made of and how they are 

connected. 

Duration—the length of time that ground motion at a 

given site shows certain characteristics. Most 

earthquakes have a duration of less than one minute, in 

terms of human perceptions, but waves from a large 

earthquake can travel around the world for hours. 

Earthquake—a sudden shaking of the ground caused 

by the passage of seismic waves. These waves are 

caused by the release of energy stored in the Earth’s 

crust. 

Earthquake hazard—any geological or structural 

response to an earthquake that poses a threat to human 

beings and their environments. 

Elevation—in architecture, a flat scale drawing of one 

side of a building. 

Epicenter—the point on Earth’s surface directly 

above the location (focus) of the earthquake below the 

surface. 

Epitaph—an inscription on a tombstone, often 

intended to sum up the achievements of a person’s life.

AGU / FEMA 361 S EISMIC S LEUTHS
EARTHQUAKE GLOSSARY 

Fault—a break or fracture in Earth’s crust along 

which movement has taken place. 

AGU / FEMA 362 S EISMIC S LEUTHS

Focus (pl. foci)—the point within the Earth that is the 

origin of an earthquake, where stored energy is first 

released as wave energy. 

Force—the cause or agent that puts an object at rest 

into motion or affects the motion of a moving object. 

On Earth, gravity is a vertical force; earthquake 

shaking includes both horizontal and vertical forces. 

Foreshock—an earthquake that precedes a larger 

earthquake, or main shock, usually originating along 

the same fault as the main shock. 

Friction—mechanical resistance to the motion of 

objects or bodies that touch. 

Frequency—the rate at which a motion repeats, or 

oscillates. The frequency of a motion is directly 

related to the energy of oscillation. In this context, 

frequency is the number of oscillations in an 

earthquake wave that occur each second. In earthquake 

engineering, frequency is the rate at which the top of a 

building sways. 

Generalization—a statement made after observing 

occurrences that seem to repeat and to be related. 

Glazing—glass surface. 

Gravity—the force of attraction between any two 

objects with mass. Gravity is especially noticeable 

when an object of great mass, such as Earth, attracts an 

object of lesser mass. 

Ground water—subsurface or underground water. 

Hazard—an object or situation that holds the 

possibility of injury or damage. 

Hertz (Hz)—the unit of measurement for frequency, 

as recorded in cycles per second. When these rates are 

very large, the prefixes kilo or mega are used. A 

kilohertz (kHz) is a frequency of 1,000 cycles per 

second and a megahertz (MHz) is a frequency of 

1,000,000 cycles per second. 

Horizontal load—the sum of horizontal forces (shear 

forces) acting on the elements of a structure. 

Index fossil—a fossil that, because its approximate 

date is known, allows scientists to determine the age of 

the rock in which it is imbedded. 

Infill—a construction method that starts with a 

structural steel or reinforced concrete frame and fills 

the empty spaces between structural elements with 

brick or hollow concrete block. 

Intensity—a subjective measure of the amount of 

ground shaking an earthquake produces at a particular 

site, based on human observations of the effect on 

human structures and geologic features. The Modified 

Mercalli Intensity scale uses Roman numerals from I 

to XII. 

Isoseismal line—a line on a map that encloses areas of

equal earthquake intensity. 

Joint—a break or fracture in the Earth’s crust along 

which movement has not taken place. 

Joists—the parallel planks or beams that hold up the 

planks of a floor or the laths of a ceiling. 

Lag time—the difference between the arrival time of 

P waves (Tp) and S waves (Ts). 

Landfill—a site where soil has been deposited by 

artificial means—often, where garbage or rubbish has 

been disposed of, then covered with dirt and 

compacted. 

Landslide—an abrupt movement of soil and bedrock 

downhill in response to gravity. Landslides can be 

triggered by an earthquake or other natural causes. 

Latitude—the location of a point north or south of the 

equator, expressed in degrees and minutes. Latitude is 

shown on a map or globe as east-west lines parallel to 

the equator. 

Lifeline—a service that is vital to the life of a 

community. Major lifelines include transportation 

systems, communication systems, water supply lines, 

electric power lines, and petroleum or natural gas 

pipelines. 

Liquefaction—the process in which a solid (soil) 

takes on the characteristics of a liquid as a result of an 

increase in pore pressure and a reduction in stress. 

Load—the sum of vertical force (gravity) and 

horizontal forces (shear forces) acting on the mass of a 

structure. The overall load is further broken down into 

the loads of the various parts of the building. Different 

parts of a building are designed and constructed to 

carry different loads.
EARTHQUAKE GLOSSARY 

Load path—the path a load or force takes through the 

structural elements of a building. 

Loess—an unstratified, windblown mixture of clay, 

sand, and organic matter, usually crumbly and buff or 

yellow-brown in color. 

Longitude—the location of a point east or west of the 

prime meridian, expressed in degrees and minutes. 

Longitude is shown on a map or globe as north-south 

lines left and right of the prime meridian, which passes 

through Greenwich, England. 

Longitudinal waves—p-waves. This term is used to 

emphasize that p-waves move particles back and forth 

in the same line as the direction of the wave. 

Love waves—surface waves that move in a back and 

forth horizontal motion. 

Magnitude—a number that characterizes the size of 

an earthquake by recording ground shaking on a 

seismograph and correcting for the distance to the 

epicenter of the earthquake. Magnitude is expressed in 

Arabic numbers. 

Masonry—stone, brick, or concrete building 

materials. 

Masonry veneer—a masonry (stone or brick) facing 

laid against a wall and not structurally bonded to the 

wall. 

Mass movement—the movement of surface material 

caused by gravity. 

Meteorology—the study of Earth’s atmosphere. 

Modified Mercalli scale of 1931—a qualitative scale 

of earthquake effects that assigns an intensity number 

to the ground shaking for any specific location on the 

basis of observed effects. Mercalli intensity is 

expressed in Roman numerals. 

Natural hazard—any of the range of natural Earth 

processes that can cause injury or loss of life to human 

beings and damage or destroy human-made structures. 

Nonstructural feature—an element of a building that 

is not essential to its structural design and does not 

contribute structural strength. Examples are windows, 

cornices, and parapets. 

Oscillation or vibration—the repeating motion of a 

wave or a material—one back and forth movement. 

Earthquakes cause seismic waves that produce 

oscillations, or vibrations, in materials with many 

different frequencies. Every object has a natural rate of 

vibration that scientists call its natural frequency. The 

natural frequency of a building depends on its physical 

characteristics, including the design and the building 

materials. 

P waves—primary waves, so called because they 

travel faster than S waves, or secondary waves and 

arrive at the station first. These waves carry energy 

through the Earth as longitudinal waves, moving 

particles in the same line as the direction of the wave. 

Paleomagnetism—the natural magnetic traces that 

reveal the intensity and direction of Earth’s magnetic 

field in the geologic past. 

Paleoseismology—the study of ancient earthquakes. 

Parapet—part of a wall which is entirely above the 

roof. 

Path, or Load path—the direction in which energy is 

distributed throughout a structure. In most structures, it 

should be directed toward the ground. 

Peat—a deposit of semicarbonized plant remains in a 

water-saturated environment. Peat is an early stage in 

the development of coal. 

Period—the time between two successive wave crests. 

Pioneer—a person who moves into new and uncharted 

territory. 

Plate tectonics—the theory that Earth’s crust and 

upper mantle (the lithosphere) are broken into a 

number of more or less rigid, but constantly moving, 

segments, or plates. 

Portico—a porch or covered walk consisting of a roof 

supported by columns 

Prediction—a statement that something is likely to 

happen based on past experience. A prediction is 

usually only as reliable as its source.

AGU / FEMA 363 S EISMIC S LEUTHS
EARTHQUAKE GLOSSARY 

Principle of crosscutting relationships—the 

principle stating that a rock is always younger than 

any other rock across which it cuts. Earthquake 

faulting illustrates this principle: Faults are always 

younger than the rocks they cut. 

Principle of superposition—the principle upon which 

all geologic chronology is based stating that in any 

sequence of sedimentary layers that has not been 

overturned or faulted, each layer is younger than the 

one beneath, but older than the one above it. 

Principle of uniformitarianism—the fundamental 

principle stating that geologic processes have operated 

in essentially the same way throughout geological 

time. 

Probability—in mathematics, the ratio of the number 

of times something will probably occur to the total 

number of possible occurrences. In common usage, an 

event is probable, rather than merely possible, if there 

is evidence or reason to believe that it will occur. 

Qualitative—having to do with perceived qualities; 

subjective. Examples: large, cold. 

Quantitative—having to do with measurable 

quantities; objective. Examples: 10 m long, 5o C. 

Radiometric dating—the process of using natural 

radioactivity to determine the age of rocks. 

Rapid visual screening (RVS)—a method of 

assessing risk that relies on external observation. An 

observer who is trained in RVS can derive enough 

information from a quick visual assessment to know if 

closer examination is necessary. 

Rayleigh waves—surface waves that carry energy 

along Earth’s surface by elliptical particle motion, 

which appears on the surface as a ripple effect. 

Recurrence interval—the actual or estimated length 

of time between two earthquakes in the same location. 

Resonance—an increase in the amplitude (a 

measurement of wave size) in a physical system (such 

as a building) that occurs when the frequency of an 

applied oscillatory form (such as earthquake shaking) 

is close to the natural frequency of the system. 

Retrofitting—making changes to a completed 

structure to meet needs that were not considered at the 

time it was built; in this case, to make it better able to 

withstand an earthquake. 

Richter magnitude—the number that expresses the 

amount of energy released during an earthquake, as 

measured on a seismograph or a network of 

seismographs, using the scale developed by Charles 

Richter in 1935. 

Rigid connections—connections that do not permit 

any motion of the structural elements relative to each 

other. 

Rotation—turning from side to side. 

Run-up elevation or height—the highest altitude 

above the tide line, in meters, that the water reaches as 

it is forced up on land by a tsunami. 

S waves—secondary waves; waves that carry energy 

through the Earth in very complex patterns of 

transverse (crosswise) waves. These waves move more 

slowly than P waves (in which the ground moves 

parallel to the direction of the wave). In an earthquake 

S waves are usually bigger Ps. 

Sag pond—a small body of water occupying an 

enclosed depression formed by fault movement. 

Sand boil—a forcible ejection of sand and water from 

saturated soil, caused by strike-slip an earthquake or 

heavy flooding. 

Saturated—having absorbed water to the point that all 

the spaces between the particles are filled, and no more 

water can enter. 

Sediment—material that has been transported by 

wind, water, or ice and come to rest in a new location. 

Sedimentary deposits—accumulations of small solid 

particles that originated from the weathering of rocks 

and that have been transported or deposited by wind, 

water, or ice. 

Seismicity—earthquake activity. 

Seismic—of or having to do with earthquakes. 

Seismic sea wave—a tsunami generated by an 

undersea earthquake. 

Seismic zone—a region in which earthquakes are 

known to occur. 

Seismogram—the record of earthquake ground 

motion recorded by a seismograph. 

Seismograph—an instrument that records vibrations 

of the Earth, especially earthquakes. 

Seismograph station—a site at which an array of 

seismographs is set up and routinely monitored.

AGU / FEMA 364 S EISMIC S LEUTHS
EARTHQUAKE GLOSSARY 

Seismology—the scientific study of earthquakes. 

Shaking—rapid horizontal vibration of the base of the 

model, simulating an earthquake. In an actual 

earthquake, of course, shaking occurs in many 

directions. 

Shear force—force that acts horizontally (laterally) on 

a wall. These forces can be caused by earthquakes and 

by wind, among other things. Different parts of a wall 

experience different shear forces. 

Shear walls—walls added to a structure to carry 

horizontal (shear) forces. These are usually solid 

elements, and are not necessarily designed to carry the 

structure’s vertical load. 

Sill plate—the structural member at the base of a 

wood frame building that joins the building to its 

reinforced concrete foundation. 

Slump—a type of landslide in which a block of rock 

or soil moves along a curved surface and rotates. 

Soft stories—stories in a building, usually lower 

stories with many openings, that are poorly supported 

or braced, and hence vulnerable to collapse. 

Stick-slip movement—a jerky, sliding movement 

along a surface. It occurs when friction between the 

two sides of a fault keeps them from sliding smoothly, 

so that stress is built up over time and then suddenly 

released. 

Strata (s. stratum)—layers of rock or other materials 

formed at different periods in geologic time. 

Strike-slip faulting—fault movement in which the 

fault is horizontal. 

Structural elements or structural features—a 

general term for all the essential, non-decorative parts 

of a building that contribute structural strength. These 

include the walls, vertical column supports, horizontal 

beams, connectors, and braces. 

Studs—upright pieces in the outer or inner walls of a 

building to which panels, siding, laths, etc. are nailed 

or bolted. 

Subduction—the process in which one lithospheric 

plate is forced down under another plate and drawn 

back into the Earth’s mantle. 

Surface waves—waves that move over the Earth at its 

surface. Rayleigh waves and Love waves are surface 

waves. 

Topography (adj. topographic)—the shape of the 

land; the contours and the arrangement of surface 

features that characterize a region. 

Torsion—twisting or turning. A building must be 

resistant to extreme torsion to resist earthquake 

damage. 

Transverse waves—waves that vibrate particles in a 

direction perpendicular to the wave’s direction of 

motion (S waves). 

Triangulation—using data from three or more known 

points to locate an unknown point, in this case, the 

epicenter of an earthquake. 

Tsunami—a potentially destructive ocean wave 

created by an earthquake or other large-scale 

disturbance of the ocean floor; a seismic sea wave. 

This Japanese word has the same form in both the 

singular and the plural. 

Unconsolidated—loosely arranged, not cemented 

together, so particles separate easily. 

Unreinforced masonry—brick, stone, or adobe walls 

without any steel reinforcing rods or other type of 

reinforcement. Buildings of this type were probably 

built before 1940. 

Variable—in a scientific experiment, the one element 

that is altered to test the effect on the rest of the 

system. 

Veneer—an outside wall facing of brick, stone, or 

other facing materials that provides a decorative 

surface but is not load-bearing. 

Vertical load—the effect of vertical force (gravity) 

acting on the elements of a structure. 

Wave height—the vertical distance from a wave’s 

crest to its trough. (This measurement will be twice the 

amplitude measured for the same wave.) 

Wave crest—the highest point a wave reaches. The 

lowest point is called its trough. 

Wavelength—the horizontal distance between two 

successive crests, often measured in meters.

AGU / FEMA 365 S EISMIC S LEUTHS