GEOLOGICAL SURVEY CIRCULAR 8 1 6 

Program and Plans of the 

U.S. Geological Survey for 

Producing Information Needed in 

National Seismic Hazards and 

Risk Assessment, 

Fiscal Years 1980-84 

Program and Plans of the 

U.S. Geological Survey for 

Producing Information Needed in 

National Seismic Hazards and 

Risk Assessment, 

Fiscal Years 1980-84 

By Walter W. Hays 

GEOLOGICAL SURVEY CIRCULAR 816 

1979 
United States Department of the Interior 

CECIL D. ANDRUS, Secretary 

Geological Survey 

H. William Menard, Director 

Free on application to Branch of Distribution, U.S. Geological Survey, 1200 South Eods Street, Arlington, VA 22202 
CONTENTS 

Abstract •.•..•..•.•••.••.••••••.•..•..•..•..•..••••.•..•..•..•.•.•.•....• • • • • • • •. • • • • • • • • • • 

Introduction ••••.•••.•...•.....•.....•.....••..•.......••........•...•........••.........•. 

Purpose ••••••••••••••••.••••••••••••••••.••••••• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 

Definition of seismic hazards and risk•••••••••••••••••••••••••••••••••••••••••••••••• 

Hhy assessments of seismic hazards and risk are needed •••••••••••••••••••••••••••••••• 

The earthquake threat••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Seismicity and faults••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

The USGS Earthquake Hazards Reduction Program••••••••••••••••••••••••••••••••••••••••• 

Sharing of responsibility between Federal, State, and local governments, and 

others .....•..••...•..•..•..•........•.•.•........••.......•.•....•..•.•.••......•.• 

Determining the needs and priorities of users••••••••••••••••••••••••••••••••••••••••• 

Examples of the needs of various users••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Surnm.ary of needs • ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Federal Government agencies••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Department of the ArmY••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Bureau of Reclamation (BUREC)•••••••••••••••••••••••••••••••••••••••••••••••••••• 

Department of Transportation (DOT)••••••••••••••••••••••••••••••••••••••••••••••• 

Bureau of Land Management (BLM)•••••••••••••••••••••••••••••••••••••••••••••••••• 

Federal Disaster Assistance Administration (FDAA)•••••••••••••••••••••••••••••••• 

Veterans Administration (VA).•••••••••••••••••••••••••••••••••••••••••••••••••••• 

National Bureau of Standards (NBS)••••••••••••••••••••••••••••••••••••••••••••••• 

Department of Energy (DOE)••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Federal Housing Administration (FHA)••••••••••••••••••••••••••••••••••••••••••••• 

General Services Administration (GSA)•••••••••••••••••••••••••••••••••••••••••••• 

Defense Civil Preparedness Agency (DCPA)••••••••••••••••••••••••••••••••••••••••• 

Nuclear Regulatory Commission (NRC)•••••••••••••••••••••••••••••••••••••••••••••• 

Federal Home Loan Bank Board••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Interagency Comflittee on Seismic Safety in Construction••••••••••••••••••••••••••••••• 

State and local government agencies••••••••••••••••••••••••••••••••••••••••••••••••••• 

Land use planners • •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Engineers and scientists•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Arc hi tee ts .•.•..... .........•..•........................•..•........•.........••...... 

Code-development groups••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Financial sector•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

User concerns and recommendations related to national seismic hazards and risk products •••• 

Overview of concerns • ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Mapping parameters ••••••••••.•..•....•••••......••.••••....•••••••...•••••••••.••••••. 

Usefulness •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Uncertainty ••• ••••••••••••••••••••••••••••••••••••••••••••••••••••• • • • • • • • • • • • • • • • • • • • 

Conservatism ••.•..•....•••.••...•.....••.•.•••••..•••••.•.....•••••.•.•••••••.•.•.•••• 

Information dissemination ....................•.....••........•........................ 

Recommendations ........................•................•...............•..•....•.•... 

Data • ••••••••••••••••••••••••••••••••••••••• • •• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 

Basic research ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Pro duets •••••••••••••••••••••••••••••••••••••••••••••••••••••• • • • • • • • • • • • • • • • • • • • 

Communication •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Examples of current USGS products used to assess seismic hazard·s and risk •••••••••••••••••• 

Summary of current products ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 

Probabilistic ground-shaking maps••••••••••••••••••••••••••••••••••••••••••••••••••••• 

What probabilistic maps depict••••••••••••••••••••••••••••••••••••••••••••••••••• 

Data requirements for probabilistic maps••••••••••••••••••••••••••••••••••••••••• 

How probabilistic maps can be extended and improved•••••••••••••••••••••••••••••• 

III 

Page 

1 

1 

1 

1 

2 

3 

5 

6 

7 

8 

8 

8 

10 

10 

11 

11 

11 

11 

11 

11 

11 

12 

12 

12 

12 

12 

13 

13 

14 

15 

15 

16 

16 

16 

16 

17 

18 

18 

18 

18 

18 

18 

19 

19 

19 

19 

19 

20 

20 

20 

22 
CONTENTS 

Page 

The USGS program in national seismic hazards and risk, FY 80-84............................ 23 

Scope and objectives•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 23 

'W'ho will do the research •• .•••.•••••••••... • •. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 25 

Research plan ••••••••••••••••••••••••••••••••• • •. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 25 

National maps based on existing methods ••••••••••••••••••••••••• -................... 25 

Definition of earthquake source zones•••••••••••••••••••••••••••••••••••••••••••••• 26 

Development of improved methods•••••••••••••••••••••••••••••••••••••••••••••••••••• 26 

Regional maps based on improved methods•••••••••••••••••••••••••••••••••••••••••••• 27 

Post-earthquake investigations••••••••••••••••••••••••••••••••••••••••••••••••••••• 27 

The communication process••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 28 

References cited •••.•••.••••••••••••••••••••••.••••••••••••• • •• • •. • • • • • • • • • • • • • • • • • • • • • • • • • 28 

Appendix A - Glossary...................................................................... 30 

Appendix B - Projects, grants and contracts funded in FY 79, Earthquake Hazards 

Reduction Program, u.s. Geological SurveY•••••••••••••••••••••••••••••••••••••••••••••••• 34 

FIGURE 1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

ILLUSTRATIONS 

Page 

Schematic illustration of a typical community with needs for assessing 

seismic risk................................................................... 3 

Comparison of isoseismal maps of 1811-1812 New Madrid, Mo., and 1906 

San Francisco, Calif., earthquakes••••••••••••••••••••••••••••••••••••••••••••• 4 

Damage at Olive View Hospital, 1971, San Fernando, Calif., earthquake.......... 4 

Damage to a single-family dwelling, 1971 San Fernando, Calif., earthquake...... 4 

Map showing locations of notable damaging earthquakes in the United States..... 5 

Surface trace of San Andreas fault near Carrizo Plain, Calif................... 7 

Schematic illustration of USGS seismic hazards and risk assessment products 

and their uses••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 10 

Schematic illustration of ways that USGS probabilistic ground-shaking maps 

are introduced into the code-development process••••••••••••••••••••••••••••••• 17 

Map of peak acceleration in rock in the conterminous United States 

(Algermissen and Perkins, 1976). A 10-percent probability exists that tl~ 

specified level of ground-shaking will be exceeded in 50 years................. 21 

Seismic zoning map of the United States, 1969.................................. 22 

Schematic illustration of the elements involved in constructing 

probabilistic maps of ground shaking••••••••••••••••••••••••••••••••••••••••••• 23 

Map showing seismic source zones in the conterminous United States............. 25 

Organization of Office of Earthquake Studies, USGS............................. 26 

TABLES 

Page 

TABLE 1. Estimates of annual- and sudden-loss potential from natural hazards in the 

United States. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 3 

2. Property damage and lives lost in notable u.s. earthquakes....................... 6 

3. Summary of funding levels of earthquake program•••••••••••••••••••••••••••••••••• 8 

4. Summary of funding of hazards assessment element••••••••••••••••••••••••••••••••• 8 

5. Projects in seismic risk and risk-related mapping funded by USGS in FY 79........ 9 

6. Division of responsibility for the Earthquake Hazards Reduction Program.......... 10 

7. The uncertainty in physical parameters that affect ground motion................. 24 

IV 
Program and Plans of the U.S. Geological Survey 

for Producing Information Needed in 

National Seismic Hazards and Risk Assessment, 

Fiscal Years 1980-84 

By Walter W. Hays 

ABSTRACT 

In accordance with the provisions of the 

Earthquake Hazards Reduction Act of 1977 (Public 

Law 95-124), the U.S. Geological Survey has 

developed comprehensive plans for producing 

information needed to assess seismic hazards and 

risk on a national scale in fiscal years 1980-

84. These plans are based on a review of the 

needs of Federal Government agencies, State and 

local government agencies, engineers and scientists engaged in consulting and research, 

professional organizations and societies, model 

code groups, and others. 

The Earthquake Hazards Reduction Act 

provided an unprecedented opportunity for participation in a national program by representatives of State and local governments, business 

and industry, the design professions, and the 

research community. The USGS and the NSF 

(National Science Foundation) have major roles 

in the national program. The ultimate goal of 

the program is to reduce losses from earthquakes. Implementation of USGS research in the 

Earthquake Hazards Reduction Program requires 

close coordination of responsibility between 

Federal, State and local governments. 

The projected research plan in national 

seismic hazards and risk for fiscal years 1980-

84 will be accomplished by USGS and non-USGS 

scientists and engineers. The latter group will 

participate through grants and contracts. The 

research plan calls for (1) national maps based 

on existing methods, (2) improved definition of 

earthquake source zones nationwide, (3) development of improved methodology, (4) regional maps 

based on the improved methodology, and (5) postearthquake investigations. Maps and reports 

designed to meet the needs, priorities, concerns, and recommendations of various user 

groups will be the products of this research and 

provide the technical basis for improved implementation. 

INTRODUCTION 

Purpose 

This report describes the program and plans 

of the USGS (U.S. Geological Survey) for producing information needed to assess seismic hazards 

and risk on a national scale. The n~eds of 

users representing Federal Government agencies, 

State and local government agencies, engineers 

and scientists engaged in consulting and 

research, professional organizations ann societies, model code groups, and others heve been 

reviewed. This review was begun in 1978, 

primarily as a consequence of the enactment of 

the Earthquake Hazards Reduction Act of 1977 

(Public Law 95-124), which directed th~ President "to establish and maintain an effective 

earthquake hazards reduction program" and to 

develop an implementation plan which "sets yearby-year targets through at least 1980." 

There can be no "final" determinetion of 

the priorities and requirements of variO'lS users 

for certain types of information to use in 

assessments of seismic hazards and risk. Needs 

for specific types of information change in 

response to diverse and complexly related political, legal, economic, and techn~logical 

factors. Consequently, the program and plans 

defined in this report reflect the USGS perception of the current needs of various u1ers for 

information. Their actual needs and our perceptions may change substantially in the next 

several years; therefore, an effective communication process between the USGS and all who use 

our products is necessary. 

Definition of seismic hazards and risk 

Used in the broad sense intended in this 

report, the term "seismic hazards" includes 

ground shaking, ground failure, surface faulting, tectonic deformation, and int'ndation. 

Geologic phenomena accompanying earthquakes, 

such as landslides, slumping, and liquefaction, 
occur primarily because of certain physical 

properties of the material at the site, but they 

can all be triggered by the ground shaking. 

The term "seismic risk" has several connotations. Its primary use refers to possible 

damage and losses (economic and life) from 

earthquakes. In this report, the term "assessments of seismic risk" refers to the procedures 

or decision-making processes followed to evaluate the possibility of damage and losses from 

earthquakes. Seismic hazard maps depict the 

geographic variation of some parameter (for 

example, peak ground-acceleration level) in 

probabilistic terms and denote the probability 

that the parameter will equal or exceed a specified value at a site during a specified exposure 

time. Seismic risk maps depict the probability 

that social or economic consequences of an 

earthquake will equal or exceed specified social 

or economic values at a site during a specified 

exposure time. Appendix A contains a list of 

terms that are used frequently in discussions of 

seismic hazards and risk and gives a common 

usage. 

Why assessments of seismic hazards 

and risk are needed 

The question of why seismic hazard and risk 

assessments are needed is illustrated schematically in terms of a typical community in figure 

1. This community not only has many existing 

physical systems exposed to the various earthquake hazards, but also may be considering many 

new construction projects. These projects might 

include siting and design of nuclear power 

plants, hospitals, dams, schools, high-rise 

buildings, oil pipeline systems, waste storage 

facilities, military facilities, and community 

lifeline systems. Each project may require an 

evaluation of the seismic risk by Federal, 

State, and local government officials and others 

in the private sector; it may also involve 

consideration of environmental impact, land-use 

planning, disaster planning, and insurance 

requirements for indemnification of losses. For 

existing and new construction, all of the political, legal, economic, and technological 

factors must be satisfactorily resolved and 

balanced. In each case, the objective is to 

make a precise assessment of the seismic risk, 

consistent with the present state of knowledge, 

and to develop an earthquake-resistant design 

appropriate for the region and specific site. 

The ultimate decisions are based on assessments 

of seismic risk on national, regional, and local 

scales; each change in scale sharpens the precision of the earthquake-resistant design for the 

specific construction under consideration. 

In the United States, the total value of 

construction exposed to the earthquake threat in 

1980 is estimated to be about $2.3 trillion 

(Office of Science and Technology Policy, 1978). 

In addition to the buildings, the contents and 

functions housed in these buildings must be 

considered in the assessment of seismic risk. 

2 

The Federal Government has a large inventory of existing structures, including buildings, hospitals, dams, highway structures, and 

military facilities, that are exoosed to the 

earthquake threat. In addition, some 35 agencies are directly or indirectly involved in and 

have a need to assess the seismic risk. Also, 

the Federal Government has a regulatory role in 

construction throughout the country, which 

sometimes requires an evaluation of the seismic 

risk by law. 

In every State, many old buildings are in 

use that do not conform to the cu-:-rent seismic 

design provisions of the Uniform B·•ilding Code. 

For example, in Los Angeles, Calif., alone, 

which has required earthquake-resistant design 

since 1933, it has been estimated that 20,000 to 

50,000 buildings fail to meet present-day standards for earthquake resistance. For other 

cities in other States, the problem is larger. 

On a national scale, the potentic-1 cumulative 

loss from old buildings in earthquakes is 

unknown, but considered to be enorm~us. 

Vital facilities and lifelin?.s exist in 

every community throughout the United States. 

Experience from past earthquakes hc-s shown that 

facilities such as hospitals, fire and police 

departments, communications and administration 

centers, and major repair and storage facilities 

must remain operational following Fn earthquake 

to insure rapid recovery. In the fRst, many of 

these facilities, as well as the er~rgy, water, 

transportation, and communication lifeline 

systems, have been located and con~tructed with 

little regard for seismic risk. As a consequence, people in these communi ties have suffered following an earthquake. 

Siting and design of critical facilities 

such as nuclear power plants, major darns, and 

nuclear-waste and liquid-natural-gas storage 

facilities receive a great deal of attention 

with regard to evaluation of seismic risk. The 

process is long, involved, and fairly well 

defined at this time. Because the cost of each 

facility can approach hundreds of millions of 

dollars and because emotional and political 

issues are usually involved, the requirement for 

evaluating the seismic risk for each facility is 

likely to become even more stringent in the 

future. 

Building codes are the only technical and 

legal requirement governing the construction of 

certain classes of private and public buildings 

in States and local jurisdictions. A building 

code imposes a general consideration of seismic 

risk. The problem, however, is that adoption of 

seismic-design requirements at the State and 

local level varies widely; more than half of the 

States do not have any type of Statewide 

building code-authority. Another sh~rtcorning is 

that building codes are generally considered to 

lag behind the current state-of-the-art in 

earthquake-resistant design. Modifications to 

building codes are usually motivated by the 
COMMUNITY CONSTRUCTION ACTIVITIES 

BUILDING I 

CODE ~ 

ENFORCEMENT 

ZONING 

ORDINANCE 

ENFORCEMENT 

STRUCTURAL FAILURE -- + t -

FOUNDATION FAILURE ----1------l 

DIFFERENTIAL SETTLEMENT 

LANDSLIDE 

FAULT RUPTURE I 

LIQUEFACTION 

LAND SUBSIDENCE 

EARTHQUAKE 

OCCURRENCE 

SOURCE 

EFFECTS PATH EFFECTS SITE EFFECTS SOil FAILURE SOIL-STRUCTURE 

INTERACTION 

STRUCTURAl 

RESPONSE 

AND DAMGE 

EARTHQUAKE RISK ASSESSMENT 

Figure !.--Schema tic illustration of a t ypical community with needs for assessing seismic risk. 

occurrence of a damaging earthquake rather than 

by scientific advances. 

The earthquake threat 

Earthquakes are one of nature's severest 

hazards. Although earthquakes have caused 

considerably less damage than hurricanes, tornadoes, and floods, they pose the largest singleevent natural hazard faced by the nation's 

population (table 1). Earthquakes can affect 

areas of hundreds of thousands of square kilometers (fig. 2), can cause great damage (figs. 3 

and 4) to single-family dwellings and other 

structures collectively valued in billions of 

dollars, can cause loss of life and injury to 

tens of thousands, and can significantly alter 

the social and economic functions of communities. 

Although the zone of greatest seismicity in 

the United States occurs along the Pacific 

coast, in Alaska, and in California, the central 

and eastern portions of the United States have 

also experienced seismic activity (fig. 5). 

Damaging earthquakes occurred in the 

3 

St. Lawrence River region on many occasions from 

1650 to 1928, in the Boston vicinity in 1755, in 

the central Mississippi Valley near New Madrid, 

Mo., in 1811-1812; near Charleston, S.C., in 

1886; and at Hegben Lake, Mont., in 1959. 

Table !.--Estimates of annual and sudden loss 

potential from natural hazards 

in the United States 

[From Wiggins, 1973.] 

Natural Annual loss 

hazard (in $ billions) 

Earthquakes---- 0.2 

Tsunami--------

Floods--------- 2.5 

Hurricanes-----

Tornados-------

Local winds----

Landslides-----

.s 

• 1 

Sudden loss 

potential 

(in $ billions) 

so 

3.5 

2. 0 

.3 
APRIL 18, 1906 

Ms = 8.3 

lZHlll 

' ' 

DEC 16, !811 

Ms = 7 5 

0 250 

Figure 2.--Comparison of isoseismal maps of 

1811-1812 New Madrid, Mo., and 1906 San 

Francisco, Calif., earthquakes. Ms denotes 

surface wave magnitude and roman numerals 

denote Modified Mercalli intensity. Dashed 

lines depict inferred isoseismal values. 

Figure 4. --Damage to a single-family dwelling, 

1971 San Fernando, Calif., earthquake 

photograph courtesy of H. S. Lew, E. V. 

Leyendecker, and R. D. Dikkers, National 

Bureau of Standards. 

Collapsed 

Ambulance Port 

Figure 3.--Damage at Olive View Hospital, 1971, San Fernando, Calif., earthquake. A, B, C, and D 

denote the four wings of the 6-story main building. Wing D is approximately 240 ft (72 m) 

long and 65 ft (20 m) wide. Photograph courtesy of H. S. Lew, E. V. Leyendecker, and 

R. D. Dikkers, National Bureau of Standards. 
~~' 

~ '

1Yokutot 

' Anchorage \ Boy 

-~196~ . ,1899 

#.~ 

_:;u:~ Boy, 1958 

Figure 5.--Map showing locations of damaging earthquakes in the United States. 

Historical earthquakes in the United States 

that have caused damage and loss of life are 

listed in table 2. Property damage in the 

United States due to earthquakes occurring since 

1865 approaches $2 billion. However, a repeat 

of the 1906 San Francisco, Calif., earthquake 

would cause losses in the tens of billions of 

dollars. The loss of life in the United States 

has fortuitously been relatively light considering the number of destructive earthquakes 

and the continually increasing population 

density in the earthquake-prone areas. Enormous 

loss of life has occurred in other countries, 

however. For example, the death toll was 

reportedly at 600,000 in the July 28, 1976, 

Chinese earthquake (Hamilton, 1978). Some 

23,000 people died in the February 4, 1976, 

Guatemalan earthquake. The Romanian earthquake 

of February 1977 killed 1,500 people. Nineteen 

hundred seventy-six was the worst year for loss 

of life from earthquakes in the world since 

1556. 

Seismicity and faults 

The seismic activity of the western and 

eastern parts of the conterminous United States 

is quite different. In the Western United 

States, the activity is very high. More large 

5 

and moderate earthquakes have occurred in California and Nevada than in all the remaining 

conterminous United States. 

The high rate of seismic activity in the 

Western United States is largely the result of 

movement along the boundary between the Pacific 

and North American plates, two of th~ major 

plates of the Earth's crust. The relative 

movement between these two plates is accommodated by slippage along the 1000-km-long San 

Andreas Fault system (fig. 6) in California and, 

to a lesser degree, along subsidiary faults in 

California and Nevada. The destructive 1906 San 

Francisco, Calif., earthquake was proc'uced by 

rupture along this fault system. Nevertheless, 

many structures, including hospitals and singlefamily dwellings, are located along tl ~ fault 

trace today and may be damaged if anoth~r large 

earthquake occurred. Also, some of the San 

Francisco Bay area communities have bee~ developed on artificial fill in tidal flats. Some of 

these areas may be susceptible to liquefaction 

(a temporary transformation of soil into a fluid 

mass) and enhanced levels of ground sh3.king in 

an earthquake. 

Surface faulting related to historic earthquakes is common in the Western United States, 
Table 2.--Property damage and lives lost in notable U.S. earthquakes 

[Taken from Report to the Congress on disaster preparedness, 

Office of Emergency Preparedness.] 

Year 

1811-12 

1865 

1868 

1872 

1886 

1892 

1898 

1906 

1915 

1925 

1933 

1935 

1940 

1946 

1949 

1952 

1954 

1954 

1955 

1957 

1957 

1958 

1959 

1960 

1964 

1965 

1971 

Locality 

New Madrid, Mo.----------

San Francisco, Calif.----

Hayward, Calif.----------

Owens Valley, Calif.-----

Charleston, S.C.---------

Vacaville, Calif.--------

Mare Island, Calif.------

San Francisco, Calif.----

Imperial Valley, Calif.--

Santa Barbara, Calif.----

Long Beach, Calif.-------

Helena, Mont.------------

Imperial Valley, Calif.--

Hawaii (tsunami)---------

Puget Sound, Wash.-------

Kern County, Calif.------

Eureka, Calif.-----------

Wilkes-Barre, Pa.--------

Oakland, Calif.----------

Hawaii (tsunami)---------

San Francisco, Calif.----

Khantaak Island and 

Lituya Bay, Alaska-----

Hebgen Lake, Hont.-------

Hilo, Hawaii (tsunami)---

Prince William Sound,----

Alaska 

Puget Sound, Wash.-------

San Fernando, Calif.-----

particularly in California and Nevada. In some 

States, such as Utah, young prehistoric fault 

scarps have been recognized. These faults may 

have the potential for generating damaging 

earthquakes in the future that would affect a 

large percentage of Utah's population. 

Surface faulting has not been associated 

with all historic earthquakes in the United 

States. In fact in the Eastern United States, 

surface faulting has not yet been recognized for 

any historic earthquake. 

The USGS Earthquake Hazards Reduction Program 

The USGS and the NSF (National Science 

Foundation) have major roles in the comprehensive Earthquake Hazards Reduction Program 

enacted by the Earthquake Hazards Reduction Act 

of 1977. The USGS program is conducted by both 

USGS and non-USGS scientists, the latter group 

participating through grants and contracts. The 

USGS and NSF programs (NFS and USGS, 1976) are 

complementary and represent a balance of six 

elements: ( 1) fundamental earthquake studies, 

6 

Magnitude 

7.1-7.2(mb) 

8.3 (est.) 

8. 3 (est.) 

8.3 (est.) 

6.3 

6. 0 

7.0 

7.1 

7. 7 

5. 3 

7. 5 

7. 5 

8. 4 

6. 5 

6. 6 

Damage 

(million 

dol.) 

.4 

.4 

.3 

23.0 

.2 

1. 4 

500.0 

6.0 

8. 0 

40.0 

4.0 

6.0 

25.0 

25.0 

60.0 

2. 1 

1. 0 

1. 0 

3. 0 

1. 0 

11.0 

25.0 

500.0 

12.5 

553.0 

LiveE' 

lost 

30 

27 

60 

700 

6 

13 

115 

4 

9 

173 

8 

8 

5 

28 

61 

131 

7 

65 

(2) earthquake prediction, (3) induced seismicity, (4) earthquake hazards assessment, 

(5) engineering, and (6) research for utilization. The funding level for each element is 

shown in table 3 for FY 78-80. 

Some 37 percent of USGS funding is allocated toward earthquake hazards assessment. The 

distribution of funding for this activity in 

FY 78 and FY 79 is shown in table 4. 

A list of projects in seismic risk funded 

by the USGS in FY 79 is shown in table 5. These 

projects involve both USGS and nor-USGS scientists. A list of all the earthquake hazards 

projects funded in FY 79 in the USGS program is 

shown in appendix B. The projects funded in 

FY 78 are listed in Hamilton (1978) and 

described in MacCabe (1979). 

USGS hazard assessment studies are currently grouped in the following cat~gories: 

1. National studies--broad-scale investigations of geographic studies to determine 

the history and likelihood cf earthquake 
-

Figure 6. --Surface trace of San Andreas fault 

near Carrizo Plain, Calif. Photograph courtesy of R. E. Wallace, U.S. Geological Survey. 

occurrence, degree of ground shaking, 

severity of geologic effects, and earthquake losses for the entire nation at a 

national scale (for example, map scale of 

1:5,000,000). 

2. Regional studies--investigations of the 

temporal and spatial characteristics of 

earthquake hazards (for example, seismicity, faulting, unstable ground, and so 

forth) and assessment of risk for regions 

of the country at high seismic risk at a 

regional scale (for example, map scale of 

1:250,000 or larger). 

3. Topical studies--investigations into the 

cause and nature of geologic earthquake 

hazards and into improved methods for 

quantitatively assessing earthquake 

hazards and risk. 

7 

4. Earthquake data 

dissemination 

services--collection and 

of data on earthquake 

occurrences and effects. 

The core of the USGS mission in the Earthquake Hazards Reduction Program is research. 

The USGS carries out and sponsors scientific and 

engineering studies that will contribute to an 

improved understanding of earthquake hazards, 

then communicates the results of these studies 

to various users. Associated with this basic 

mission is a variety of other functions related 

to the USGS role as the Federal Government's 

expert on earthquake hazards. For example, the 

USGS frequently serves as a reviewer and consultant for other Federal Government agencies that 

are faced with decisions involving technical 

issues related to earthquake hazards, such as in 

the siting of nuclear power plants, hospitals, 

dams, and oil pipelines and in the preparation 

of disaster plans. USGS personnel often serve 

on advisory committees for other Federal agencies (for example, National Aeronautics and 

Space Administration (NASA), Department of 

Energy (DOE), Department of Defense (DOD), State 

agencies (for example, Utah Seismic Safety 

Advisory Council, California Strong Motion 

Instrumentation Program), and other types of 

organizations (American Nuclear Society Standards Committee, American Society of Civil 

Engineers Nuclear Materials and Structures 

Committee, Earthquake Engineering Research 

Institute). In addition, the USGS sometimes 

represents the United States in assisting 

foreign countries in dealing with their technical earthquake-related problems. 

Sharing of responsibility between Federal, 

State, and local governments, and others 

The Earthquake Hazards Reduction Act 

provided an opportunity for participation in a 

national program by representatives of State and 

local governments, business and industry, the 

design professions, and the research community. 

The ultimate goal of the USGS Earthquake Hazards 

Reduction Program is to reduce losses from 

earthquakes. These mitigation actions are taken 

by Federal agencies; by local, regional, and 

State levels of government; and by the private 

sector. The USGS is usually not directly 

responsible for implementation, but is often 

involved as an intermediary or as an informal 

consultant to those who are. 

The division of responsibility between the 

Federal, State, and local governments is shown 

in table 6. Many of the USGS scientific studies 

are such that additional studies are needed to 

make them applicable on a site-specific basis. 

For example, the regional hazards mapping 

performed by the USGS may be at a scale of from 

1:250,000 to 1:63,360, whereas land-use planning 

decisions require maps on a much larger scale. 

The link between the national and regional 

research products of the USGS and specific 
Table 3.--Summary of funding levels of earthquake program 

(in millions of dollars) 

FY 80 

Subelement FY 78 FY 79 Request 

Fundamental earthquake studies 

(NSF and USGS)---------------------- 7. 9 9. 1 10.2 

Prediction (USGS)--------------------- 16.0 15.9 15.5 

Induced seismicity (USGS)------------ 1. 2 1. 2 1. 2 

Hazards assessment (USGS)------------ 10.8 11.1 11.3 

Engineering (NSF)--------------------- 18. 1 17.4 18. 3 

Research for utilization (NSF)------------------------ 2. 0 .8 5.0 

USGS total------------- 30.7 31.2 31. 7 

NSF-------------------- 25.8 32.4 38.9 

Table 4.--Summary of funding of hazards 

assessment element 

(in percent) 

FY 78 

National studies--------------- 7 

Regional studies--------------- 59 

California~------------------ 26 

Western---------------------- 16 

Eastern---------------------- 17 

Topical studies---------------- 32 

Earthquake potential--------- 7 

Ground motion---------------- 13 

Ground failure--------------- 7 

Risk------------------------- 3 

Post-earthquake 

investigations------------- 2 

Program management------------- 2 

FY 79 

7 

59 

26 

16 

17 

32 

7 

13 

7 

3 

2 

2 

implementation actions is appropriately 

performed by intermediaries. The intermediaries 

include private consultants and consulting 

companies in the scientific, engineering, and 

planning fields; professional organizations; 

government agencies at all levels of government; 

public interest groups; and others. 

The total process of reducing earthquake 

hazards involves three basic groups of people: 

(1) researchers, who generate new knowledge; 

(2) intermediaries, who translate and synthesize 

this knowledge into material that provides a 

basis for decisions; and (3) implementors or 

decisionmakers, who effect the mitigation 

actions needed at the community level. Success 

depends on how well these three groups interact 

and cooperate throughout the period of time 

needed to accomplish the goal. 

8 

Determining the needs and priorities of users 

Over the years, the USGS has developed a 

number of procedures for determining the needs 

and priorities of users for USGS products. 

During the past 2 years, special attention has 

been given to finding effective ways of defining 

needs for products to be used in assessing 

seismic hazards and risk. The most effective 

contact procedures have proven to be (1) workshops (such as that convened in Vail in October 

1978), which bring together leading authorities 

in the fields of geology, seismology, and earthquake engineering and users such as decisionmakers in Federal, State, and local governments, 

members of professional societies, model code 

groups, and the Interagency Committee on Seismic 

Safety in Construction; (2) "cluster" meetings 

with State Geologists and other State and local 

officials concerned with evaluation of seismic 

hazards and risk; (3) questionnaires; and 

(4) frequent correspondence. By implementing 

these and other communication procedures, the 

USGS has succeeded in developing a critical 

perception of the needs and priorities of the 

various users who have responsibility for the 

assessment of seismic hazards and risk. These 

needs will be described in the following 

section. 

EXAMPLES OF THE NEEDS OF VARIOUS USERS 

Summary of needs 

The process of developing the implementation plan required by the 1977 Earthquake 

Hazards Reduction Act has uncovered a large and 

diverse group of users who have responsibilities 

for assessments of seismic hazards and risk. 

Some of these users are shown schematically in 

figure 7. Their needs are numerous and varied: 

1. Evaluation on a national scale--these 

applications primarily require maps that 

show relative geographic variations in 

earthquake hazards, including young 
Table 5.--Projects in seismic risk and risk-related mapping 

funded by USGS in FY 79 

Project 

Seismogenic zones of the United States. 

Regional and national seismic hazard 

and risk. 

A new attempt at seismic zoning maps 

for southern California. 

Microzonation of the Memphis, Tenn., 

area. 

Methods of probabilistic seismic-----

hazard assessment. 

Probabilistic seismic hazard of the 

Outer Continental Shelf. 

Experimental mapping of liquefaction 

potential. 

Preliminary assessment of liquefaction 

potential in and near San Juan, 

Puerto Rico. 

Development of data bases, parameters, 

and methods for converting ground 

motion to expected dollar loss for 

high-rise buildings. 

Development of an exposure model for the 

United States building wealth and 

annual economic loss consequence of 

the various seismic risk maps. 

A stochastic and Bayesian model for-----

hazard mapping and for estimating 

earthquake losses. 

An alternating Markovian process for----

earthquake occurrences. 

Principal investigator 

J. I. Ziony, USGS. 

s. T. Algermissen, USGS. 

c. R. Allen, California 

Institute of Technology. 

w. D. Kovacs, Purdue Univ. 

R. K. McGuire, USGS. 

D. M. Perkins, USGS. 

T. L. Youd, USGS. 

T. L. Youd, USGS. 

R. E. Scholl, URS/ 

John A. Blume and 

Associates. 

J. H. Wiggins, 

J. H. Wiggins Co. 

H. C. Shah, 

Stanford Univ. 

H. C. Shah, 

Stanford Univ. 

faults, potential or historic ground 

motion, and ground failure. The maps are 

used to identify high risk areas for 

insurance indemnification and earthquake 

zoning and to establish program priorities, design criteria, and public 

policy. 

2. Evaluation on a regional scale--these 

applications primarily require maps and 

publications that describe the relative 

geographic distribution and nature of 

earthquake hazards. The maps and publications are needed for actions that 

include land-use zoning, building code 

development, community development, 

siting of critical facilities, disasterpreparedness planning, and public policy. 

3. Evaluation of the potential for strong 

ground mot ion and ground failure at 

specific sites--these applications 

require reports, maps, and guidelines 

that synthesize information to develop 

methods, to provide a basis for determining design criteria, and to define 

public policy. 

9 

4. Information on seismicity and earthquake 

effects--these needs require data, maps, 

and interpretative reports showi.ng current and historic earthquake locations 

and earthquake effects. Uses include 

post-earthquake relief operations, engineering-scientific-sociological investigations following an earthquak€, deci-
Table 6.--Division of responsibility for the 

Earthquake Hazards Reduction Program 

sionmaking on both individual and group 

levels, and various research activities 

carried out by universities, professional 

societies, and others. 

Aspect of program 

Level of government 

responsibility 

Federal Government agencies 

Development of new Federal. As indicated earlier, some 35 Federal 

Government agencies have responsibility either 

for construction or construction-related activities. These agencies are involvei in assessments of seismic hazards and risk for facilities 

such as nuclear power plants, hosri tals, dams, 

military facilities, nuclear-Faste-storage 

repositories, highway structures, and housing. 

Some examples of the needs of Federal agencies, 

as defined in the communication process 

described above, are generalized ard summarized 

below. These statements represent USGS perceptions of their needs. 

techniques. 

Demonstration projects. --------Do.-------

National hazards assessment. --------Do.-------

Regional hazards Federal, State, 

assessment. regional, and 

local. 

Local hazards assessment. State, regional, 

and local. 

Land use planning. --------Do.------- Department of the Army 

Standards, codes, ~-------Do.-------

regulations. 

In the Army's military programs, implemented by the Corps of Engineers, the primary 

needs are for (l) refinement of methods to 

INSURANCE 

ANALYSTS 

3 

ALL 

BLDG. 

DESIGN 

4 

WATER 

SUPPLY 

AND 

SANITATION 

USGS PRODUCTS 

e EARTHQUAKE POTENTIAL 

e GEOLCX>IC FACTORS INFLUENCING GROUND MOTION 

e REGIONAL NETWORKS 

e EARTHQUAKE HAZARDS 

e EARTHQUAKE RISK 

2 

PLANNERS 

2 2 

BLDG. SITE 

CODES DESIGN 

3 

CODE 

DEVELOPERS 

4 

BRIDGE 

AND 

TUNNEL 

USES 

4 

COMMUNICATION 

FACILITY 

POST-EARTHQUAKE INVESTIGATIONS 

e GROUND-MOTION RECORDS 

e ISOSEISMAL DATA 

e DAMAGE DISTRIBUTION 

e EARTHQUAKE REPORTS 

4 

SITE ENGINEERS 

4 

ELECTRICAL 

AND 

POWER 

4 

TRANSPORTATION 

FACILITY 

5 

STRUCTURAL 

ENGINEERS 

AND 

ARCHITECTS 

4,5,6 2 

DISASTEF 

PLANS u AND 

DESIGN DESIGN FACILITY LAND USr: DESIGN 

REDUCTION OF 

PERSONAL INJURIES 

AND FATALITIES 

GOALS 

REDUCTION OF LOSS TO PROPERTY AND STRUCTURES 

1. Public Buildings 6. Dams 

(especially schools) 7. Public Utility 

2. Multi-story Buildings. Facilit1es (especially 

3. Commercial Buildings Aqueducts and canals) 

4. Residences 8 Nuclear Reactors 

5. Bridges and Tunnels 9. Area Site Design 

DEVELOPMENT OF 

REALISTIC EARTHQUAKE 

INSURANCE COVERAGE 

6 

UNIVERSITIES 

EARTHQUAKE 

INSURANCE 

PLANS 

Figure 7.--Schematic illustration of USGS seismic hazards and risk assessment products and their 

uses. 

10 
determine design earthquakes for use in the 

design of hospitals and dams located in various 

regions in the United States; (2) update of 

seismic zone maps (Algermissen and Perkins, 

1969, 1976; Applied Technology Council, 1976) 

for the United States and territories, currently 

used in the Uniform Building Code and the TriService Seismic Design Hanual (Depts. of Army, 

Navy, and Air Force, 1973); (3) establishment of 

the best relations between the values of peak 

ground acceleration and velocity and the seismic 

risk zones, and ( 4) development of guidelines 

for determining design earthquakes for vital and 

(or) critical facilities in terms of seismic 

risk and exposure time. 

Bureau of Reclamation (BUREC) 

For siting of dams and other hydraulic 

structures, BUREC needs maps showing the probability of future ground-shaking levels and fault 

rupture on both national and regional scales. 

The relations between ground motion and faulting 

mechanisms need to be established, especially 

close to the fault. Assessments of seismic 

hazards and risk need to be based on standardized guidelines and an information base 

containing information about induced seismicity, 

seismogenic zones, earthquake-source strength 

(magnitude), and faults. 

Department of Transportation (DOT) 

DOT owns more than 12,000 facilities 

throughout the United States which consist of 

over 34,000,000 ft 2 of space located on 193,000 

acres of land. The Coast Guard, Federal 

Aviation Administration, Alaska Railroad, 

St. Lawrence Seaway Development Corporation, and 

Transportation Systems Center all own or operate 

facilities within high seismic risk zones. To 

fulfill its requirements for seismic hazards and 

risk assessment, the following products are 

needed: (1) regional- and national-scale maps 

showing the intensity of ground shaking for 

various probabilities of earthquake occurrence 

that can be used in the siting of highway, 

railroad, and airport structures; (2) maps of 

coastal areas that depict the intensity of 

ground shaking, tsunami inundation, and liquefaction potential for various probabilities of 

earthquake occurrence, to apply to port facility 

design; (3) maps showing active faults that can 

be used in conjunction with maps of ground 

shaking for design, construction, and retrofit 

of pipeline structures; and (4) maps showing 

areas of potential seismically induced land/rock 

slides that can be used for land-use planning of 

transportation structures. 

Bureau of Land Management (BLH) 

BLM needs maps showing the location, frequency of occurrence, and intensity of shaking 

of earthquakes for land use planning, environ11 

mental statements, dam construction, ani other 

activities. Evaluation of seismic hazards and 

risk on undeveloped public lands is ne~ded if 

temporary relocation is adopted as a viable 

earthquake mitigation measure. 

Federal Disaster Assistance AdminiE'tration 

FDAA (now part of the Federal Errergency 

Management Agency) is responsible for the preparation of earthquake damage studies for ~elected 

urban areas in high seismic risk zones. Studies 

of four areas--San Francisco, Calif.; Los 

Angeles, Calif.; Puget Sound, Wash.; and Salt 

Lake City, Utah--have been complete--1 with 

assistance from the USGS. Similar studies are 

currently planned by FDAA for Anchorage, Alaska, 

and for Hawaii and may also require USGS 

assistance. 

Veterans Administration (VA) 

The VA needs to quantify which States, 

geographic areas, and population centers are 

vulnerable to the earthquake threat, b')th for 

existing and new hospitals. National and 

regional seismicity maps are needed, as well as 

maps depicting the variation of ground-shaking 

parameters and ground failure in terms of the 

frequency of earthquake occurrence. These maps 

should be continually updated to incorporate the 

best available geologic information and to 

assist the VA to continually update its design 

standards (VA, 1973). 

National Bureau of Standards (NBS) 

NBS has responsibility for develorment of 

seismic design and construction standards, for 

consideration and subsequent application in 

Federal construction, and for encouraging the 

adoption of improved seismic provisions in State 

and local building codes. To fulfill this 

responsibility, national and regional rr"\ps are 

needed that show earthquake ground shaking 

effects (acceleration, velocity, and duration) 

in probabilistic terms, suitable for estimating 

loads on buildings and for regional zoning. 

Multiple maps for a single effect (for example, 

acceleration for several probabilities of 

exceedance) are more useful than a sirgle map 

for one probability of exceedance. 

Department of Energy (DOE) 

In its Waste Isolation Safety Program, DOE 

needs a long-term (thousands of years) predictive capability for evaluating seismic hazards 

and risk. The goal is to be able to predict 

with a high confidence that future ear+:hquakes 

will not cause significant faulting cr. other 

seismic hazards in the geologic environment 

where a waste repository is located. National 

and regional maps showing faults, seismicity, 
and regional tectonic movement and their interrelations are needed. DOE is also responsible 

for assessing the hazards and risk for nuclear 

reactor sites. 

Federal Housing AdQinistration (FHA) 

At the present time, FHA has a relatively 

limited role in enforcing rules, standards, 

regulations, and seismic requirements. However, 

agency policies and standards, such as the 

MinimuQ Property Standards, do have significant 

impact upon design and construction of residential buildings throughout the country. At the 

present time, FHA has adopted the 1973 edition 

of the Uniform Building Code for seismic design 

of new construction, but has adopted the policy 

of less than 100 percent compliance with 1973 

code requirements for existing buildings. The 

primary and continuing need of FHA is for information that will help to establish criteria for 

better housing, taking into account state-ofthe-art seismic requirements and their cost 

impact. The priority need is for maps that 

depict seismic hazards and risk, especially in 

the Eastern United States, in terms of the 

probability of earthquake occurrence. Damageestimation studies are also needed to develop 

the capability for estimating damage from ground 

shaking and ground failure to ( 1) masonry oneto four-family homes, (2) wood fraQe one- to 

four-family homes, (3) high-rise commercial and 

industrial structures, and (4) nonresidential 

structures. FHA wants to upgrade its "Methodology for seismic design and construction of 

single-family dwellings" (Dept. of Housing and 

Urban Development, 1976). 

General Services Administration (GSA) 

In executing its responsibility for the 

design and construction of Federal buildings, 

GSA uses the seismic design criteria contained 

in its 1978 publication, "Design Guidelines." 

In its assessment of seismic hazards and risk, 

GSA needs national and regional-scale maps 

showing (1) active faults, (2) ground failure, 

(3) potential tsunamis or seiches, (4) damfailure inundation, (5) local ground conditions 

that might enhance ground shaking, and 

(6) ground-motion characterizations. The most 

urgent need is for much more data showing actual 

building performance and soil-structure 

interaction during an earthquake for buildings 

of varying sizes, construction materials, and 

design concepts. 

Defense Civil Preparedness Agency (DCPA) 

DCPA (now part of the Federal Emergency 

Management Agency) is not directly involved in 

building design and construction programs. 

However, agency personnel advise State and local 

12 

civil defense organizations on the current 

assessment of seismic hazards and risk in their 

area for emergency preparedness purposes, and 

provide "Summer Institutes." To cBrry out these 

responsibilities, DCPA needs a series of maps 

that depict the variation of groun~ shaking and 

other seismic hazards in terms of frequency of 

earthquake occurrence in a given exposure time 

for States, regions, and the entire United 

States. 

Nuclear Regulatory Commission (NRC)_ 

NRC is responsible for a variety of 

research and regulatory activities connected 

with the siting of nuclear power plants. The 

emphasis in current research is placed on 

(1) regional and tectonic evaluations in the 

Eastern United States; (2) evaluation of engineering methods and practices that are used to 

mitigate the effects of eartlguakes; and 

(3) quantification of the levels of conservatism 

that are currently incorporated into seismic 

design. NRC's program is coordinated closely 

with the activities of other agencies, including 

the USGS, NSF, COE, and many State agencies. 

The overall objectives of the NRC research 

program are similar to many of those in the USGS 

Earthquake Hazards Reduction Pro.'!ram, except 

that priority emphasis is placed on the Eastern 

United States and the objective level of hazard 

mitigation required for nuclear power plants is 

much higher than that for conventional civil 

structures. NRC needs almost every research 

product in seismic hazards and risk that the 

USGS is currently working on. In particular NRC 

needs empirical data about ground-motion characteristics close to the fault. In the Eastern 

United States, one of the primary needs is to 

develop a systematic procedure for defining 

earthquake source limits. Probabilistic maps of 

gr~und shaking having return periods as long as 

10 years are needed. 

Federal Home Loan Bank Board 

As a Federal financial regulatory agency, 

needs for seismic hazard and risk assessment 

products are limited to those potentially useful 

for protecting the viability of the Federal 

Savings and Loan Insurance Corporation. The 

most needed products are maps delineating 

moderate- and high-risk areas accompanied by 

tables showing pertinent factors, such as 

(1) percentage probability of vario•ls levels of 

earthquake ground shaking within the next 25, 

50, or 100 years; (2) valuation of residential 

and commercial properties at risk; (3) population; (4) estimated loss in terms of lives and 

property at various levels of gro·md shaking; 

and (5) estimated capability of comll'nnity public 

services to survive and to respond to a severe 

earthquake. 
Interagency Committee on Seismic Safety 

in Construction 

The newly created Interagency Committee on 

Seismic Safety in Construction is an example of 

a group that will use USGS research products and 

exert considerable influence on many agencies of 

the Federal Government and various other user 

groups in the next several years. This committee is composed of representatives of all 

Federal agencies that are significantly engaged 

in construction, the financing of construction, 

or various construction-related activities. 

This committee is organized into 10 subcommittees that are dealing with (1) format and 

notation; (2) standards for buildings; 

(3) existing buildings; (4) lifelines; (5) risk 

analysis; (6) grant, lease, and regulatory 

programs; (7) evaluation of site hazards; 

(8) tsunamis and flood waters; (9) postearthquake serviceability; and (10) critical 

facilities. The goal of the Committee is to 

develop a common set of standards, codes, and 

practices with regard to all Federally funded, 

assisted, and regulated construction. This 

committee will play an important role in standardization of terminology and procedures within 

the Federal sector. 

State and local government agencies 

Within each State, numerous government 

agencies and groups are concerned with seismic 

hazards and risk. These groups include 

( 1) State geological surveys; (2) State seismic 

safety advisory groups; (3) regional governmental bodies; ( 4) emergency preparedness 

groups; and (5) city planners. These agencies 

and groups have differing responsibilities with 

respect to evaluation of seismic hazards and 

risk, but all need USGS products to augment 

their capability for making assessments of 

seismic hazards and risk on a State and local 

scale. 

Each State geological survey, depending on 

the State, its individual resources, and legislative mandates, is involved in some way with 

the assessment of seismic hazards and risk. In 

California, for example, the California Division 

of Mines and Geology has a staff which performs 

many functions, including (1) research; 

(2) post-earthquake investigation; (3) fault 

mapping; (4) strong-motion instrumentation; and 

(5) monitoring of the Alquist-Prioli special 

fault study zones. On the other hand, in 

Wisconsin, which has a low level of seismicity, 

the staff of the State Survey is smaller; its 

functions in seismic hazards and risk assessment 

are largely advisory and primarily concern 

issues such as earthquake potential and active 

faults arising in regard to siting of important 

facilities. 

The continuing record of cooperation 

between the USGS and the State surveys in the 

13 

Earthquake Hazards Reduction Program is good. 

The State surveys have an opportunity for participation in the planning of each USGS research 

project and in the grants and contracts program. 

Reports, maps, and other information developed 

in the program are transmitted to each ccqcerned 

State, often prior to publication for reyiew and 

always as they are published. 

At the present time, four States have 

seismic safety advisory groups: California, 

Utah, Montana, and Nevada. California's Seismic 

Safety Commission, formed in 1973, las the 

longest record of experience in the development 

of public policy with respect to seismic safety. 

The general responsibilities of these advisory 

groups vary within the four States, b·.tt they 

collectively include: 

1. providing advice to the governor and legislature on earthquake safety matters; 

2. recomnending a consistent policy framework 

for seismic safety within the State; 

3. suggesting goals and priorities for earthquake hazards reduction; 

4. recommending Statewide and local programs 

to reduce earthquake hazards; 

5. recommending methods for improving building 

standards and construction conpliance 

with the standards; improving siting and 

design of critical facilities, hospitals, 

and schools; and delineating fault zones 

that require special investigations, 

regulation, and reporting procedures; 

6. educating the public and private sectors on 

seismic safety; 

7. recommending training for specialized 

enforcement and technical personnel; and 

8. reviewing proposed earthquake-related 

legislation and proposing needed legislation. 

To carry out these responsibilities, 

seismic safety advisory groups need infcrmation 

about seismic hazards and risk that can be 

applied on the community (or city-planning) 

scale. Land-use practices determine where 

buildings and development occur relative to 

seismically hazardous zones. It is in tre cityplanning process that decisions are made regarding the siting of most buildings, critical 

facilities, and lifelines. Planning professionals need to know: 

1. the location and nature of earthquake 

hazards, 

2. the potential effect of the hazard to 

public safety and welfare, 

3. the regulatory tools that are available to 

provide equal treatment for equal problems on a standardized basis, 
4. the mitigation procedures that can be 

implemented by nonprofessionals, and 

5. the availability of technical expertise to 

evaluate the exceptions from routine 

regulations. 

The experience of the Utah Seismic Safety 

Advisory Council, formed in 1977, is probably 

typical of the implementation process that might 

be expected in many States. Utah has experienced only a few damaging earthquakes having 

Modified Mercalli intensity ranging from VII to 

IX since 1850. Although large earthquakes have 

not occurred in historic time, the geologic 

record contains clear evidence that the Wasatch 

fault zone has been active for millions of years 

and that the faults within this extensive zone 

may have the potential for generating a large 

(magnitude (Ms) 7.5) earthquake. Thus, many 

public policy issues need resolution, including 

( 1) building codes and construction standards; 

(2) land-use-planning practices; (3) hazards and 

risk mapping; (4) strong-motion instrumentation; 

and (5) vital facilities such as schools, hospitals, police stations, fire stations, lifelines, 

and dams. Recommendations to correct possible 

deficiencies in seismic safety require time for 

considerable study and assessment before legislation can be proposed. To be successful, each 

proposed earthquake-hazard-mitigation measure 

must be accomplished through programs that are 

specifically tailored to the local seismic risk 

and fitted to existing procedures of government. Progress in earthquake hazard reduction 

in any State requires time and a balance of 

private sector-State-Federal support. 

Regional government bodies can play an 

important role in the assessment of seismic 

hazards and risk on a local scale. Two groups 

with contrasting, but representative, experiences are (1) Association of Bay Area Governments (ABAG), in northern California; and 

(2) Mississippi-Arkansas-Tennessee Council of 

Governments (MATCOG), in the metropolitan 

Memphis, Tenn., area. 

ABAG is a regional planning agency operated 

by the local governments of the San Francisco 

Bay Area. It was established in 1961 to meet 

regional problems through cooperative action of 

its member cities and counties and to perform 

three main planning and coordinating functions 

( 1) reviewing plans and projects of local 

governments; (2) assisting local governments in 

obtaining earth sciences information from USGS, 

California Division of Mines and Geology, and 

other groups; and (3) providing advocacy for 

regional concerns at both the State and Federal 

levels. ABAG's contributions in the HUD/USGS 

San Francisco Bay Region Environmental and 

Resources Planning Study and in the development 

of seismic safety elements are a model for other 

regional governments to follow (Perkins, 1978). 

14 

MATCOG, a regional planning agency for 

metropolitan Memphis, Tenn., was responsible in 

1972 for developing a long-range plan to improve 

the seismic safety in the region. The HUDfunded study considered (1) improvements in 

earthquake-resistant design; (2) lifeline 

systems; (3) planning regulations; and 

(4) disaster recovery plans. Mann (1978) noted 

that although Memphis is not far from the 

revised location of the epicenter of the 1811-12 

New Madrid earthquakes, no seismic design 

requirements and a low level of seismic awareness presently exist within the co11munity, and 

official reaction was varied and ronproductive 

to the finding of the 1972 MATCOG study showing 

that the risk of damage from an e~rthquake is 

higher than previously thought. Mann (1978) 

concluded that it is difficult to motivate and 

educate decisionmakers and various public 

interest groups in the Central United States to 

be earthquake-conscious because of the lack of 

recent "triggering" events, and that people seem 

to respond best to the earthquake hazard if they 

are given earthquake-loss information that can 

be compared easily with loss data from more 

familiar natural hazards (for example, flood, 

tornado). 

Within every State and local government, 

various agencies and groups have responsibility 

for preparedness and response in the event of an 

earthquake or other disaster. They work closely 

with Federal agencies (for example, FDAA) and 

other local groups (for example, h-:~spitals and 

hospital associations or councils; natural gas, 

electric, and telephone utilities; and American 

Red Cross). These agencies and groups need a 

complexly integrated balance of earth-science, 

management-science, economic, political-science, 

and sociological data to execute their responsibility (Buck, 1978). The four eartrquake-damage 

studies performed jointly by FDAA and the USGS 

for San Francisco, Calif. (Algermissen and 

others, 1972), Los Angeles, Calif. (Algermissen 

and others, 1973); Puget ?ound, Wash. (Hopper 

and others, 1975); and Salt Lake City, Utah 

(Rogers and others, 1976), represent the current 

extent of the USGS involvement in this type of 

seismic hazard and risk assessment. Additional 

studies of this type are planned in the future 

by FDAA for other urban areas in the United 

States and may require USGS assistarce. 

Land use planners 

Land-use planning encompasses all the 

decisions affecting the locations of physical 

improvements in a locale or community. Examples 

of the varied aspects of land-use planning 

include (1) policies at ~ Federal level for 

interstate-freeway locations; (2) p~licies at a 

State level for dam safety; (3) policies of 

lending institutions for good lendirg risks; and 

(4) policies of cities and counties for subdivision design and zoning ordinances. 
Land-use planning at the local level calls 

for establishment of goals, conducting research, 

and assessing seismic hazards and risk. It 

involves six areas of activity: 

1. preparation and maintenance of general 

plans, 

2. zoning of land, 

3. regulation of subdivisions, 

4. regulation of building and grading (shared 

with building officials), 

5. urban-renewal planning, and 

6. planning for public buildings and other 

structures. 

In most communities throughout the country, 

these activities have been performed in the past 

with little regard for seismic safety. Only 

California has developed the concept of a 

seismic safety element; however, other States 

are now considering it. 

In California following the 1971 

San Fernando earthquake, the State Planning Law 

was amended to require that each city and county 

in the State prepare and adopt a Seismic Safety 

Element (SSE) as part of its general plan. The 

preparation of a SSE required the following: 

1. recognition of seismic hazards and their 

possible effect on the community, 

2. 

3. 

identification of general 

reducing seismic risk, 

goals for 

specification of the level or nature of 

acceptable risk to life and property, 

4. specification of seismic-safety objectives 

for land use, and 

S. specification of objectives for reducing 

the seismic hazards to existing and new 

structures. 

In many cases, USGS results were used 

substantially in the preparation of the SSE 

(Young, 1978; Kockelman, 1978). However, no 

State requirement exists at present to force 

local jurisdictions to complete their general 

plans and, of the 412 cities and 58 counties in 

California, 81 cities and 19 counties still did 

not have an SSE in January 1977 (Olson, 1978). 

Engineers and scientists 

Many engineers and scientists in the 

private sector and in universities throughout 

the United States are engaged in a wide variety 

of activities requiring knowledge of seismic 

hazards and risk. These activities include 

earthquake-resistant design, consultation, and 

research and development. Only the broad scope 

of needs of this diverse group of users can be 

15 

summarized. Discussions at three USGS~ponsored 

workshops, held in 1975, 1977, and 1978, have 

established that engineers and scientists want 

to know the answers to questions such as the 

following: 

1. Where have the earthquakes occurre~ in the 

past? 

2. Where are the earthquakes occurring now? 

3. What are the source parameters (magnitude, 

seismic moment, stress drop) of these 

earthquakes? 

4. What are the characteristics of tl'~ ground 

motion close to the fault? 

5. What are the characteristics of th~ seismic 

waves as they attenuate from the source? 

6. What kinds of geologic effects (surface 

faulting, ground failure, tectonic deformation, inundation) occurred during each 

earthquake? 

7. What was the distribution of damag~ in each 

earthquake? 

8. Did local ground conditions enhance the 

level of ground shaking, and, if so, what 

was the horizontal and vertical spatial 

variation? 

9. On the basis of the best available data, 

what characteristics of ground shaking 

and ground failure are expected at the 

proposed construction site in the next 

25, SO, 100, 200 years? 

The structural engineer has the ultimate 

responsibility for developing earthquakeresistant design. He is the one who mt•st integrate the technical answers to questions such as 

those listed above with the legal, political, 

economic, and technological constraints to 

effect the appropriate seismic design. Because 

the vast majority of structures do not have and 

cannot justify an individual assessment of 

seismic hazards and risk, the level of seismic 

design is commonly set by the building code 

adopted by the State and (or) local community in 

which the construction is located. 

Architects 

An architect's responsibility in the design 

of a building includes functional planning 

(space layout), but may or may not include site 

selection. The architect is legally accountable 

for meeting certain minimum safety an<l health 

requirements, as prescribed by applicalle codes 

and standards, and is professionally accountable 

for creating a serviceable facility wj thin the 

legal, political, economic, and technological 
constraints. If earthquake-resistant design is 

the goal, the architect needs to know the following: 

1. the primary and secondary earthquake 

hazards for the site, 

2. the potentiai damage mechanisms for that 

type of building which have been observed 

during past earthquakes, 

3. the seismic forces associated with these 

potential damage mechanisms, 

4. alternative design arrangements and assemblies that will accommodate the potential 

seismic forces, and 

s. the expected limits of 

techniques to resist 

seismic forces. 

the 

the 

alternative 

potential 

The priority needs of the architect are for 

hazards and risk assessment products that correlate directly with building design criteria. If 

the criteria differ for various building types 

and occupancy levels, then the specificity of 

the hazards and risk assessment products must 

also differ. If microzonation eventually 

replaces regionwide seismic risk zones, then 

larger scale hazard and risk maps will be 

required. It should be emphasized, however, 

that the vast majority of buildings constructed 

in the United States are one- to five-story 

structures, not large complexes or high-rise 

structures, and they do not routinely receive 

rigorous site and engineering analysis because 

of economic constraints. In this case, the need 

is for seismic-design values rather than methodologies. 

Code-development groups 

The International Conference of Building 

Officials (ICBO) is a representative example of 

a group involved in the development of building 

codes that incorporate seismic-design provisions. Development of these provisions is a 

continuously evolving process which is directly 

related to the changing state-of-the-art. 

Building codes have to satisfy many segments of 

society and to balance legal, political, 

economic, and technological constraints. The 

goal is to develop a concept of seismic risk 

zoning which allows everyone throughout the 

United States to adopt mitigative measures that 

are reasonable and equitable in terms of the 

local seismic hazards. 

To evolve seismic-design provisions for use 

in building codes, code-development groups 

require national-scale maps that delineate the 

variation of the maximum ground motion and 

incorporate frequency of earthquake occurrence 

and exposure times. These maps must depict a 

ground-motion parameter (for example, peak 

acceleration) that can be directly translated 

16 

into a building-design parameter contained in 

the code formulation. 

The USGS has participated in the evolution 

of building codes that consider seismic-design 

provisions since 1969 (Algermissen, 1978). The 

primary ways currently used by the USGS to 

introduce seismic-hazards and risk information 

into the code-development process are illustrated in figure 8. 

Financial sector 

Whether or not, earthquake risl: is carried 

by a financial institution or transferred to an 

insuror, each group has a similar requirement 

for information. Each must make judgments that 

will enable it to achieve itE' goals of 

(1) pricing, so that cost of insurance is at 

least equal to earthquake loss; and (2) husbanding capital, so that maximum probable loss 

situations are met. To achieve these goals, the 

financial sector needs the follow~.ng information: 

1. the areal extent of ground shaking, ground 

failure, and inundation for upper-bound 

events on various faults and tectonic 

structures throughout the United States; 

2. the geographical variation of these effects 

within each potentially affected area; 

and 

3. the recurrence times or return periods of 

these effects for various levels of 

ground shaking. 

The first item will permit th~ establishment of a maximum probable loss expectancy 

which, in turn, will permit management of 

dollar-loss exposure to the extent that it can 

be accommodated within the financial institution 

or shared with others. The secord item will 

reflect the expected damage in individual structures at risk in the area. The seccnd and third 

items in combination will provide a basis for 

pricing of insurance that adequately reflects 

"how bad and how often." 

Each of the user groups descrit·~d above has 

concerns about the information th~t the USGS 

provides or will provide to them for assessing 

seismic hazards and risk. These concerns are 

discussed in the following section. 

USER CONCERNS AND RECOMMENDATIONS 

RELATED TO NATIONAL SEISMIC HAZARDS 

AND RISK PRODUCTS 

Overview of concerns 

Past workshops and other ccmmunications 

have shown that a broad range of perspectives 

are represented in each user group and that each 
INTERNATIONAl UNIFORM 

CONFERENCE OF ... 

- BUilDING 

BUilDING OFFICIAlS CODE 

l 

- SEISMOlOGY .. I SUBCOMMITTEE 

APPliED TECHNOlOGY COMPREHENSIVE 

COUNCil ~ 

~ SEISMIC-DESIGN 

(grant from NSF) PROVISIOt•s 

... RISK ASSESSMENT • .. COMMITTEE 

u.s. 

GEOlOGICAl 1--- DEPARTMENT OF MINIMUM 

SURVEY HOUSING AND "' PROPERTY .. URBAN DEVElOPMENT STANDARC'~ 

-. - FEDERAl HOUSING ... ADMINISTRATION 

DEPARTMENT OF TRI-SERVICE 

DEFENSE --- SEISMIC 

DESIGN MANUAl 

l ... OFFICE, CHIEF .. OF ENGINEERS 

Figure B.--Schematic illustration of ways that USGS probabilistic ground-shaking maps are 

introduced into the code-development process. 

group has particular concerns. Some of these 

concerns cut across all of the user-group boundaries. They include (1) what parameters should 

be mapped; (2) the usefulness of the map products; (3) how to depict uncertainty; (4) how to 

minimize conservative tendencies; and (5) how to 

disseminate the information effectively. Each 

of these concerns will be discussed and followed 

by some general recommendations. 

Mapping parameters 

This concern is discussed frequently 

because there is general agreement that a map of 

a single ground-motion parameter (for example, 

peak acceleration) is a simplistic approximation 

of the ultimate product needed by the user com17 

munity. The engineer argues that he nee.ds data 

on ground motion, not just on peak acceleration, 

and that peak acceleration may not alway~ be the 

best way to characterize ground shaking. Some 

of the limitations on peak acceleration are the 

following: (1) it seems to be weakly dependent 

on magnitude; (2) its effect on short- ar~ longperiod buildings is not well understood; (3) it 

does not correlate well with Modified r·'!rcalli 

intensity or with all aspects of dama'!e; and 

(4) its large values, as defined by recent 

instrumental records obtained near the source, 

are not always practically important and may 

need to be reformulated as an "effective peak 

acceleration" (Whitman, 1978). The co111pelling 

counterargument for using peak acceleration is 

that it is a fundamental ground-motion parameter 
directly available from the strong-motion accelerogram without interpretation or derivation. 

Other ground-motion parameters that might 

be mapped include (1) peak and "effective peak 

velocity;" (2) peak displacements; (3) Modified 

Mercalli intensity; (4) duration of shaking; and 

(5) spectral velocity for several period bands. 

The ultimate map is one that depicts the time 

history of ground shaking at a site, but such a 

map is beyond the current state-of-the-art. 

Probabilistic maps of faulting and ground 

failure can also be constructed. However, with 

the exception of liquefaction opportunity maps 

(Youd and Perkins, I97 8), none of these maps 

have been produced yet. 

Usefulness 

How USGS seismic hazard and risk assessment 

products will meet the needs of various user 

groups, individually and collectively, is the 

key question. As noted previously, the needs 

for specific products vary between user groups 

and as a function of time. Triggering events 

can also change the priority of a user's needs. 

For example, the I97I San Fernando earthquake 

resulted in reevaluation and modification of the 

criteria for siting and design of hospitals and 

other critical facilities. One way the USGS 

might enhance the usefulness of its seismic 

hazards and risk assessment products is to focus 

first on the development of those products that 

are relatively simple, based on fundamental (not 

derived) data, and free as possible from controversial or unproven interpretations and analyses. 

Uncertainty 

The question that characterizes this user 

concern is, "How does one depict on a seismic 

hazard or risk map the uncertainty in the values 

of the mapped parameter that arises from uncertainties in the data used to derive the map?" 

The best current example of the problem is 

depicting what we know and do not know about 

earthquake hazards ih the Eastern United States. 

Conservatism 

In most cases, the evaluation of seismic 

hazards and risk is a controversial process. 

The controversy is caused, in part, by debate 

about whether the available geologic, geophysical, seismological, and geotechnical data are 

adequate to specify the hazards and risk precisely and whether conservatism introduced into 

the earthquake-resistant design specification is 

reasonable in view of the uncertainties in the 

data. For example, six empirical procedures are 

currently used to introduce conservatism into 

the design spectrum for a nuclear power plant 

(Hays, 1979a). They are (l) selecting a low18 

probability, extreme seismic event and moving it 

to the closest epicentral distance to the site; 

(2) using smooth, broadband, m~an-plus-onestandard-deviation design spectra which are 

derived to be independent of the epicentral 

distance from the site; (3) using a mean-plusone-standard-deviation regional seismicattenuation function; (4) requiring that the 

design time histories produce response spectra 

that envelop the design spectra; (5) requiring 

that the two horizontal-component design time 

histories have equal values of peak ground 

acceleration and that the vertical component has 

a peak value that is two-thirds or more of the 

peak horizontal-ground acceleration; and 

(6) modifying the smooth design spectrum to 

account for local ground response. 

The question that characterizes this user 

concern is "Who will introduce the conservatism?" The position of most users is that the 

hazards and risk assessment products of the 

Survey should be based on the best available 

"hard" data and that all data anc" methodology 

should be well described in reports that accompany every map. 

Information disseminatic~ 

The basic question is ''How does a user 

obtain a Survey seismic hazard or seismic risk 

map when he needs it, even though the map may be 

preliminary?" This question has no easy answer, 

but it appears that one solution is to publish 

dated, well-documented, preliminary maps through 

professional journals and USGS open-file reports 

to provide information on a timely basis and 

then to publish "final" maps in formal USGS 

publications. 

Recommendations 

The following recommendations ~re a summary 

of those made by participants in the October 

1978 USGS-sponsored workshop on seismic hazards 

and risk (Hays, 1979b). They touch on the 

subjects of (I) data, (2) basic research, 

(3) products, and (4) communication. Each 

recommendation should be integrated with the 

above statements of user concerns and viewed in 

terms of the current scope and balance of the 

USGS Earthquake Hazards Reduction Program. (See 

''Introduction" and appendix B). 

Data 

The USGS should use its resources to 

acquire important information now lacking 

about ground-motion effects. Examples 

include (I) ground motion for magnitude 

(Ms)-6 to -8 earthquakes close to the 

source, and (2) data to defin~ the horizontal and vertical spatial ·wuiation of 

ground motion. These data should be disseminated to the earthquake engineering 

community and incorporated in seismic 

hazards and risk assessment proiucts. 
Post-earthquake investigations should be 

carried out following each important earthquake in order to take advantage of unique 

opportunities to acquire badly needed data 

about ground motion and ground failure 

effects. 

The USGS should be a national resource for 

the "hard" data on seismicity, ground 

motion, and ground failure. 

The USGS should take the lead in establishing a national seismic network capable 

of detecting and locating earthquakes of 

magnitude 4 (M1 ) and greater and in disseminating the data to the concerned community 

of users. 

Basic research 

The USGS should keep emphasizing fundamental research on topics such as seismogenic zones, capability of faults, 

seismicity (including reservoir-induced 

seismicity), ground-motion characterization, and geologic effects. 

The USGS should utilize data from earthquakes occurring worldwide to refine models 

of ground motion, ground failure, and 

seismic risk assessment. 

The USGS should quantify the uncertainty in 

all empirical relations derived for hazards 

and risk assessments. 

The USGS should consider research on decisionmaking using limited data, utilizing 

knowledge and concepts now available in 

many business schools. 

Products 

The USGS should develop the seismic hazards 

and risk assessment products that are 

simplest first, as well as publishing 

intermediate products and dated maps. 

The USGS should develop "guidelines" along 

with the research report to suggest ways 

that the research results might be implemented. 

The USGS should use its resources to 

prepare suites of probabilistic ground 

motion maps to show the parametric sensitivity and the consequence of different 

tectonic models. These maps should be 

properly identified as research products, 

dated, and accompanied by a report that 

identifies the data base, methodology, 

assumptions, and so forth. 

The USGS should participate in multidisciplinary committees (such as the Inter19 

agency Committee on Seismic Safety in 

Construction) to define user needs and the 

interfaces between disciplines. 

The USGS should construct maps for spe~ific 

uses in addition to those for a "ge""eral 

purpose" use. 

Communication 

The USGS should make greater use of openfile reports and journal article~ to 

publish "preliminary" seismic hazarde- and 

risk assessment products and use Pr--fessional Papers and other formal USGS p·lblications for "final" products. 

The Survey should help in the education of 

public officials and the various users of 

seismic hazards and risk assessment products. 

The Survey should develop a procesS" for 

introducing change in a seismic hazar~s or 

risk assessment map and implement it, 

involving the entire scientific and engineering community. 

The following section discusses USGS products that are used in the assessment of seismic 

hazards and risk. 

EXAMPLES OF CURRENT USGS PRODUCTS USED 

TO ASSESS SEISMIC HAZARDS AND RISK 

Summary of current products 

To meet the needs of user groups for USGS 

research products to use in their assessments of 

seismic hazards and risk, the USGS is pres~ntly 

producing products such as the following: 

National probabilistic 

map of peak ground 

acceleration. 

National maps showing 

young faults. 

Maps and catalogs of 

earthquake epicenters 

and improved earthquake locations. 

Seismotectonic maps. 

Example 

Algermissen arli 

Perkins, 197 6. 

Howard and otl,~rs, 

1977. 

Na tiona! Eartl'-

quake Infontation Servic~'s 

"Preliminary 

Determination 

of Epicenters;" 

Stover, 1977; 

Dewey, 1979. 

Hadley and 

Devine, 1975; 

Heyl and 

McKeown, 1978. 
Studies of recurrence 

intervals of faulting 

on specific faults. 

Disaster preparedness 

studies. 

Post-earthquake 

investigation. 

Analysis of earthquake hazards. 

Estimation of economic 

and life loss. 

Bucknam and 

Anderson, 1979. 

Algermissen and 

others, 1972; 

Algermissen 

and others, 

1973; Hopper 

and others, 

1975; Rogers 

and ·others, 

1976. 

U.S. Geological 

Survey and 

National 

Oceanic and 

Atmospheric 

Administration, 

1971; Espinosa, 

1976; Rankin, 

1977. 

Borcherdt, 1975. 

Rinehart and 

others; 1976; 

Algermissen, 

McGrath, and 

Hanson, 1978; 

Algermissen, 

Steinbrugge, 

and Lagorio, 

1978. 

Probabilistic ground-shaking maps 

The national probabilistic map of peak 

ground acceleration (fig. 9) is a good example 

of a USGS product that is widely used. A brief 

discussion will enable the reader to have a 

broad perspective about (1) what probabilistic 

maps depict; (2) the technical data needed to 

construct a probabilistic map; and (3) how a 

probabilistic map can be extended and improved. 

The reader who is interested in more detail 

should refer to the publications by Cornell 

(1968), Algetmissen (1973), Hays and others 

(1975), Algermissen and Perkins (1976), and 

Karnik and Algermissen (1978). 

What probabilistic maps depict 

The map shown in figure 9 was prepared by 

Algermissen and Perkins (1976) and used in the 

definition of seismic zones in the Applied 

Technology Council's model code. Unlike earlier 

seismic zoning maps (fig. 10), which were based 

on Modified Mercalli intensity without regard 

for frequency of occurrence, this map depicts 

the variation of a ground-shaking parameter in 

terms of probabilities that a certain level of 

ground motion will occur at a specific location 

in a given interval of time. The map represents 

the ground-shaking hazard across the United 

States in a uniform manner, taking into account 

20 

the differences in seismicity in the Eastern and 

Western United States and the geologic characteristics of seismic source zones. The hazard 

is depicted in terms of contoured values of the 

peak ground acceleration expected 1n a 50-year 

period at the 90 percent probability level at 

sites underlain by rock. Another Fay to state 

the probability is that there is c- 10 percent 

probability of exceeding the value of peak 

acceleration shown on the map ir a 50-year 

interval at rock sites. 

The term "return period" is fre-:~uently used 

in the discussion of seismic hazard.s and risk. 

Return period differs from exposure time, the 

interval of time (for example, 50 years) a 

structure is exposed to the earthquake threat. 

Return period is the time that is required (on 

the average) to experience the recurrence of a 

certain level of ground acceleration. It is 

defined in terms of the ratio of the average 

number of earthquakes it takes to experience an 

acceleration exceeding "a" to the: number of 

earthquakes expected each year. The return 

period is 475 years for peak a~celerations 

having an exceedance probability of 10 percent 

in a 50-year period; it is 1 million years for 

peak accelerations having an exceedance probability of 0.5-percent in a 50-year period. The 

corresponding risks are 0.002 and 0.000001/year. 

Data requirements for probabilistic maps 

Construction of a probabilistic groundshaking map, such as that shown in figure 9, 

requires the best available data on {1) seismicity, {2) seismic source zones, and (3) attenuation. The elements involved in pre~aring a map 

are illustrated schematically in fi.gure 11 and 

are discussed below. 

The first step is to assemblE'! seismicity 

data and to decide upon the spatial and temporal 

distribution of the earthquakes in discrete 

seismic source zones. In defining the seismic 

source zones, all available inforn1a tion about 

the correlations between earthquake~ occurrence 

and other geologic processes and structures, are 

used, including: 

1. location of the boundaries of crustal 

blocks undergoing contrastir~ displacements, 

2. history of vertical and horizontal regional 

tectonic movements, 

3. location and history of active faults, and 

4. tectonic stress. 

The seismic source zone is chosen so that it 

encloses an area of seismic activity and, to the 

extent possible, an area of related tectonic 

elements. Earthquakes are assumed to be equally 
... 

rt 

\ 

I 

\ -----} 

'· 

Z!l O Contounln,.....,.l ~'0/~~ \ -· --' .... ?-;:'~-:-3-=~~3~~4:-:'S,LJ 3_---J614 G • <' 

0 

' ~ j SCALE IN KM ,__ 

Figure 9. -Map of peak acceleration in rock in the conterminous United States (AlgermisE'"!n and 

Perkins, 1976). A 10-percent probability exists that the specified level of ground-shaking 

will be exceeded in 50 years. 

likely anywhere in the source zone, to have an 

average rate of occurrence that is constant in 

time, and to follow a Poisson distribution of 

recurrences. For each source zone the recurrence 

relation is based on the statistical parameters 

of the log N versus intensity (or magnitude) 

curve derived from the seismicity data. For the 

map of Algermissen and Perkins (1976) seventyone seismic source zones were defined for the 

United Sta..t:es (fig. 12). The seismic source 

zones are larger in the Eastern United States 

than in the Western United States, reflecting 

comparative levels of lack of knowledge. 

A key step involves the calculation of the 

severity of ground shaking on rock at every 

location of interest or in the "affected area." 

The affected area in figure 11 consists of a 

large rectangle that is subdivided into subrectangles of constant latitude and longitude 

(inset A). The grid points at which the calculations are made are located at the centers of 

these subrectangles. The seismicity (inset B) 

is apportioned among the grid points in accordance with the location of the seismic source 

zones. The calculation sums the effects of each 

level of seismicity of each seismic source zone 

at each of the grid points of the affected 

area. The end result is a ground-shakir~ parameter (for example, peak acceleration) determined at each grid point of the affected area. 

A set of attenuation curves (inset B)(for 

example, Schnabel and Seed, 1973) that sr"!cifies 

how the ground motion parameter decreases with 

distance from the source for a given ep:l'.central 

intensity or magnitude is essential for this 

determination. 

The probability distribution function 

(inset C) of the ground-shaking parameter is 

calculated at each grid point. This distribution function allows one to determine (1) the 

number of times that a particular level of 

ground acceleration is likely to occt':t' in a 

given period of years at a given site, and 

(2) the maximum level of acceleration for any 

level of probability. Contour maps can then be 

prepared to show the variation of peak ground 

acceleration in terms of exposure times and 

probability levels (inset D). 

Analogous ·procedures are involved when 

preparing probabilistic maps of other groundshaking parameters (for example, peak w~locity, 

peak displacement, spectral velocity at discrete 

periods, duration). 

21 
ZONE 

0- No damage \ ·-· "· 

M

. . ,, I - tnor damage; dtstont earthquakes may cause '-l 

damage to structures with fundamental periods -~ 

greater than 1.0 cseconds; corresponds to intensities 1 

Vond VI of the Modified Mercolli scale. ·._ 

ZONE 2- Moderate damage; corresponds to intensity 

VII. 

ZONE 3- Major damage; corresponds to intensity VIII and higher. 

~ 

\ 

\ 

25° 

MILES 

0 100 200 300 400 500 

Thies mop is based on the known distribution of do mag ing earthquakes and the 

intensities associated with these earthquakes. 

\ 0 161 805 

90° 85° 80° 75° 

Figure 10.--Seismic zoning map of the United States, 1969 (Algermissen, 1969). This map, with 

modifications, is incorporated in the 1979 edition of the Uniform Building Code. 

How probabilistic maps can be extended 

and improved 

The key to extending and improving probabilistic ground-shaking maps is to improve the 

definition of each of the three primary components required to construct the map; namely, 

seismicity, seismic source zones, and regional 

attenuation functions. The ground motion 

produced by an earthquake is a complex function 

of the tectonic province in which the earthquake 

occurs, the earthquake source mechanism, and the 

geology between the source and the site. The 

most important parameters are summarized in 

table 7 along with information about the effect 

of each parameter on ground motion and the 

uncertainty in some of the empirical relations. 

The statistical distribution of many of these 

parameters is lacking or poorly defined at this 

time because of limited data, especially in the 

Eastern United States. 

The seismicity record in the United States 

is quite variable regionally and encompasses 

about 100-400 years. It is impossible to 

specify the exact location and magnitude of the 

22 

upper-bound earthquake that will occur in a 

tectonic province containing a construction site 

on the basis of the seismicity alone, for 

geologic studies are the most definitive method 

for defining upper-bound magnitud~ and recurrence. Additional seismic! ty networks may be 

needed in some areas. Analysis of the 2, COOyear seismicity record of China (M~Guire, 1979) 

has shown that detailed, long-term knowledge of 

the seismicity is required to define precise 

recurrence relations needed for evaluating 

seismic hazards and risk on a national scale. 

Construction of regional-scale maps and maps for 

very low probabilities of exceedance or very 

long exposure times also requir?.s long-term 

knowledge of the seismicity. 

Most researchers argue that the greatest 

hope for extending and improving the current 

probabilistic map of ground acceleration is to 

improve the definition of seismic source zones, 

especially in the Eastern United States. This 

work is underway, and current results in South 

Carolina (Rankin, 1977) seem to indicate that 

the greatest advances are made through multidisciplinary geologic and geophysical studies. 
1.0 

~ ·~ ~ ~ 0.8 

i i 0 ci 

<= ci .E 

¢ 

SOURCE 1 

. ¢:J 

z ~ II 0.2 -

:"§: 

~ OL-----------

ACCELERA liON ACCELERA liON 

Figure 11.--Schematic illustration of the 

elements involved in constructing probabilistic maps of ground shaking. A shows 

three typical seismic source zone configurations and the grid of points at which the 

ground acceleration hazard is calculated. B 

shows typical statistical representations of 

seismicity for the three source zones and 

acceleration attenuation curves for the 

region. C depicts a typical cumulative 

probability distribution F(a) of ground 

acceleration at site. D shows the extreme 

probability Fmax t(a) for various ground 

acceleration levefs and exposure times T at a 

site. Acceleration values obtained in D for 

every site form the basis of a contour map 

such as figure 9. 

Characterization of the ground motion close 

to the fault is one of the most difficult parts 

of the scientific problem. In the near-field 

(that is, distances of a few fault widths from 

the earthquake energy source), the ground motion 

is strongly influenced by the dynamics of the 

fault rupture. In this region, the dynamic 

stress drop primarily determines the highfrequency characteristics of the seismic waves 

(and consequ~ntly the peak ground acceleration), 

and the permanent static displacement determines 

the low-frequency characteristics. At this 

time, only a few accelerograms, such as t:hat 

recorded at Pacoima Dam during the 1971 San 

Fernando earthquake, are available to define the 

amplitude level and spectral characteristics of 

near-field ground motion. Substantial improvement in probabilistic ground shaking maps will 

come only as this gap in knowledge is closed, 

perhaps as the recommendations made at the May 

1978 NSF-sponsored workshop on "Strong motion 

earthquake instrument arrays" (!wan, 1978) are 

implemented to acquire near-source ground-motion 

records throughout the world in high seirmicity 

areas. 

At the present time, insufficient data are 

available to define precise attenuation functions for various regions of the United ftates. 

The few attenuation functions that are widely 

used (for example, Schnabel and Seed, 1973; 

Donovan, 1973) are acknowledged to have limitations, especially close to faults and outside 

California. The ideal case would be to "calibrate" the frequency-dependent attenuation 

characteristics of various regions of the United 

States by obtaining a set of records for the 

whole range of variables (distance, focal depth, 

magnitude, region) and a reference ground condition. 

The probabilistic method of constructing 

ground-shaking maps has advantages th~t the 

deterministic methods do not have. A groundshaking map derived deterministically cannot 

reflect the statistical distribution of p~ysical 

parameters that affect ground motion. Probabilistic maps are based on deterministic 

methods, but they reflect parameter uncertainty. 

Probabilistic methods are also being used 

to produce maps of liquefaction opportunity 

(Youd and Perkins, 1978). The approach is 

similar, so these maps will not be discussed 

here. 

THE USGS PROGRAM IN NATIONAL 

SEISMIC HAZARDS AND RISK, FY 80-8ll 

23 

Scope and objectives 

During the next five years (FY 80-·FY 84), 

the USGS plans to continue its research program 

in national seismic hazards and risk at about 

the current level of funding. The objectives 

will continue to be the same; namely, (1) to use 

existing methods for making maps; (2) to develop 

improved methods for more precise delineation of 

these effects; and (3) to assess the risk. This 

research program will continue as a subelement 

of the "Hazards assessment element" (see tables 

3, 4) one of the six elements constituting the 

NSF-USGS Earthquake Hazards Reduction Program; 

therefore, the program is dependent on the technical progress made in the individual research 

projects within that element. As noterl in the 

preceding section, the capability to construct a 

map that accurately depicts the variation of 

ground shaking nationwide requires improved 

technical knowledge from ongoing research 

activities: 

1. improvement in the location, accuracy, and 

completeness of historic earthquake data, 

including a remapping of poorly located 

earthquakes and redefinition of critical 

parameters in the data base; 
N 

..j::'-

Table 7.--The uncertainty in physical parameters that affect ground motion 

Physical 

parameter 

Seismicity 

parameters: 

Seismic source zone----

Recurrence rate (b)----

Upper bound magnitude--

Source parameters: 

Epicenter--------------

Focal depth------------

Magnitude (mb, ML, Ms) 

Seismic moment (M0 )---

Stress drop (Aa) and 

effective stress. 

Fault length (L)-------

Epicentral intensity (10 ) 

Path parameters: 

Attenuation of seismic 

energy with distance. 

Local site parameters: 

Soil-rock acoustic impedance (pS) contrast. 

Soil thickness and geometry. 

Strain level---------------

Transfer function----------

Effect on 

ground motion 

Controls location of 

earthquakes. 

Defines frequency of 

occurrences. 

Establishes ground-motion 

design levels. 

Establishes location of 

design earthquake. 

Affects partition of 

body/surface waves. 

Affects low frequencies; 

ground-motion scaling. 

Affects low frequencies--

Affects high frequencies; 

peak acceleration. 

Affects magnitude and 

moment. 

Affects site acceleration 

(aH and av). 

Establishes peak groundmotion values at site. 

Affects amplitude level 

of ground motion. 

Affects dominant 

frequency, duration. 

Determines if ground 

response is linear. 

Determines relative 

response between sites. 

Uncertainty 

Not known; function of seismicity record 

and geologic and tectonic history. 

5=0.45 in Eastern United States where 

Log N=a-bl; a=f(N). 

Not known; function of seismicity record 

and fault rupture. 

Best location accuracy is 

50 km. 

km; worst is 

Best location accuracy is 2 km; worst is 

50 km. 

Best accuracy is 0.1 unit; worst is 

)1 unit. 28 

Log M -3/2 Ms until M~IO dyne-em. 

=~1.9+3 log L with la~2. 

Earthquakes exhibit a constant average 

stress drop of about 10 bars with 2aS10. 

ML=l.235+1.243 Log L; a=0.93. 

Log aH=0.24 IMM+0.26; la=2.19 WORLDWIDE 

Log av=0.28 IMM-0.40; la=2.53 DATA 

Not well defined; la for peak acceleration 

vs. distance is 2.01 for worldwide data. 

!a for frequency-dependent attenuation of 

spectral velocity ranges from 1.61 to 2.22. 

The statistical distribution for Modified 

Mercalli intensity attenuation is not 

known. 

Not well defined. 

Not well defined. 

Not well defined because of limitations 

of the ground-motion data sample. 

Repeatable with la=l.30 for nuclear 

explosions and 1.50 for earthquake 

aftershocks. 
Figure 12.--Map showing seismic source zones in the conterminous United States (AlgermisPen and 

Perkins, 1976). 

2. 

3. 

4. 

s. 

6. 

identification 

faults; 

of seismically active 

definition of earthquake recurrence intervals from analysis of the Quaternary 

history of individual faults; 

delineation of seismic source zones on the 

basis of seismic, geologic, and geophysical characteristics; 

specification of seismic attenuation functions for various regions of the United 

States; and 

post-earthquake investigations. 

Who will do the research 

The research in the national seismic 

hazards and risk program will be accomplished by 

USGS scientists, with management responsibility 

being assigned primarily to the Branch of Earthquake Tectonics and Risk (fig. 13), and by nonUSGS scientists and engineers through grants and 

contracts. Viewed as a whole, the research will 

be multidisciplinary and involve geologists, 

geophysicists, and engineers. 

25 

Research plan 

The projected research plan in n~tional 

seismic hazards and risk for FY 80-84 is 

described below. This plan is based on a consideration of (1) the needs, prioritier, concerns, and recommendations of variou1 user 

groups; and (2) the resources currently available within the USGS to perform the re~earch. 

The research plan does not identify specific 

research tasks that might be performed by nonUSGS scientists and engineers because of the 

constraints of the procurement procedure. However, it is anticipated that considerable 

research on component parts of the national 

seismic hazards and risk program will be conducted through grants and contracts. 

National maps based on existing methods 

A number of probabilistic maps of ground 

shaking on a national (1: 7, 500, 000) scale will 

be developed during the period FY 80-84. The 

various maps and other products tha.t will 

receive priority attention are listed below. 

However, circumstances beyond our control (for 

example, studying the effects of a destructive 

earthquake in the United States) would take 

priority over some ongoing studies an-'~ might 

cause a delay in publication. 
I OHlU Ot EARTIK)l'AKE I '>Tl'DUS 

J R. L. Wesson J 

I EARTHQUAKE IIAZARI~ I PROGRAM COORDINATION 

R. A. Page I 

I I I I I I 

I 

I GRA:O.T'i A."D CONlllACI'S I \11\:\"AGE\IE:O.T 

I J. F. El'f!rndRn I 

PROJECfS IN OTHER 

OFFICES OF THE 

GEOLOGIC DIVISION. USGS 

Jlll\'CII 01 

'>IJ\\11( 

Jlll\'CIIOI Jill\'( II 01 

1.\Killl)l \lo.l Jill\'( 1101 IIIII'( II 01 JIR\'( II 01 Bli"CIIOI GRA:\'TS ASD CONTRACTS WITH UNIVERSITIES 

STATE AGENCIES, 

PRIVATE FIRMS, AND 

OTHERS 

(,JIOl 'I> \IUill>' '>I·J"IIll IK.l II C'l O'OI'IIl '>IC'> "·T\IOHK <,tl"IICITl \'I> 

I ,I,"IJ-H"C. ri-C'IO,IC'> \"JHI'>Io. \'I> I \lll"l· OPI·R\HO''> HIHII'i'llllCillU-. --~--~ 

H.IJ. llordu•rtll F. 4 . . WcKemrn R. D. &m·herdl D.I'.Ht/1 C B. Raleigh J.P. f:aton E. R. Engdahl 

Figure 13.--0rganization of Office of Earthquake Studies, USGS. 

1. National map showing the annual probability 

of acceleration of 0.10 g. 

2. National map of historical maximum Modified 

Mercalli intensity. 

3. National-scale maps of acceleration and 

velocity for rock sites in the Outer Continental Shelf. 

4. National probabilistic maps of maximum 

Modified Mercalli intensity. 

5. National probabilistic maps of acceleration 

and velocity for rock sites. 

Definition of earthquake source zones 

An effort is currently underway to delineate earthquake source zones nationwide using 

existing methods and geologic and geophysical 

data. The objective is to refine the current 

characterization of earthquake source zones and 

the existing data bases so that improved 

national and regional-scale probabilistic maps 

of ground shaking can be developed. The map and 

accompanying text of the report that is expected 

from this research is listed below. The list 

does not contain maps and reports that will be 

produced through grants or contracts. 

Map or report 

1. Map of earthquake source zones for coastal 

Alaska (1:7,500,000). 

2. Map of earthquake source zones for coastal 

California (1:7,500,000). 

3. Map of earthquake source zones for coastal 

southeast United States (1:7,500,000). 

4. Map of earthquake source zones for coastal 

northeast United States (1:7,500,000). 

26 

5. Map of earthquake source zones for coastal 

northwest United States (1:7,500,000). 

6. Map of focal mechanisms for North America 

(1: 11,000,000). 

7. Map of late Quaternary faults in Utah categorized according to esti~~ted age of 

last movement (1:250,000 and 1:500,000). 

8. Map of stress determination~ for North 

America (1:2,500,000). 

9. Report on geologic and seismologic studies 

in the upper Mississippi Emb~yment area. 

10. National map of earthquake source zones. 

11. Revised seismicity catalog for the United 

States. 

12. Report on geologic and seismologic studies 

in the upper Mississippi Embayment area. 

13. Seismicity map of 

(1: 5, 000,000). 

the Un.ited States 

14. State seismicity maps (1:1,000,000). 

Development of improved methods 

Concurrent with the mapping effort, a 

research effort is also underway to develop 

improved methods for making probatilistic maps 

of ground shaking and ground faj lure. This 

effort is summarized below with identification 

of the map or report being prepared. 

1. 

Map or report 

Redetermination of epicenters of 

mentally recorded earthquakes 

Eastern United States. 

instruin the 

2. Methods for estimating e-round-motion 

characteristics close to a fault. 
3. Methods for incorporating variability in 

ground-motion parameters. 

4. Methods for assessing liquefaction potential, taking account of duration of 

shaking and number of stress cycles. 

5. Regional attenuation functions for peak 

acceleration and velocity. 

6. Catalog of observed Modified Mercalli 

intensities in the United States. 

7. Regional attenuation functions for Modified 

Mercalli intensity. 

8. Recommended revision to Modified Mercalli 

intensity scale. 

9. Methodology for assessing source regions 

for long return periods. 

10. Frequency-dependent attenuation relations. 

Regional maps based on improved methods 

The current plan is to develop a series of 

maps of ground shaking and possibly ground 

failure on a regional scale (1:250,000 or 

larger). These maps will be based on improved 

methods and data and will incorporate the best 

available information about seismic source 

zones. They will be a useful extension of the 

national-scale maps. It is anticipated that 

they will include information such as (1) age 

dating of faults, especially in California, 

Nevada, and Utah; (2) understanding of the 

characteristics of intraplate earthquakes, especially in the Eastern United States; and 

(3) understanding of the physical correlations 

between earthquake occurrence, regional tectonics, and basement features (for example, 

volcanic intrusives, rift zones), especially in 

the Eastern United States. The maps will be 

developed first for those urban areas of the 

United States where sufficient advances in 

understanding of earthquake source zones have 

occurred to warrant refining the national-scale 

maps and will require interaction with the 

States. The map or report being prepared is 

listed below. 

Map or report 

1. Map of probabilistic liquefaction potential, San Juan, Puerto Rico. 

2. Probabilistic maps of economic loss for the 

San Francisco Bay region. 

3. Maps of probabilistic ground shaking for 

the Wasatch Front area, Utah. 

4. Map of probabilistic liquefaction potential, southern California. 

27 

5. Probabilistic maps of economic loes for 

Wasatch Front area, Utah. 

6. Probabilistic maps of economic loss for the 

Mississippi Embayment area. 

7 • Maps of probabilistic ground shaking for 

the Mississippi Embayment area. 

8. Maps of probabilistic ground shaking for 

the Charleston, S.C., area. 

9. Probabilistic maps of economic loss for the 

Charleston, S.C., area. 

Post-earthquake investigations 

The USGS will coordinate with other groups 

in sending a team to investigate each important 

damaging earthquake throughout the world and in 

publishing the data and results. Damaging 

earthquakes provide a unique opportunity to 

improve the level of scientific knowledge about 

earthquake source zones, geologic effects, and 

the nature and distribution of eartl'1Uakerelated losses. The types of seismological, 

engineering, economic, and sociological data 

available after a damaging earthquake include 

the following: 

1. identification of the direction of faulting, 

2. identification of active tectonic elements, 

3. ground-motion records and improved correlation of ground motion with damage, 

4. understanding of the mechanism of occurrence of faulting and ground failure, 

5. test of building 

quake-resistant 

practice, 

performance and earthdesign and construe tion 

6. primary and secondary economic effects, and 

7. sociological changes caused by the event. 

All of these data are critically important to 

nearly all phases of earthquake hazard and risk 

evaluation and contribute, eventually, to 

improved earthquake-resistant design. 

Earthquakes in foreign countries as well as 

in the United States are important sources of 

information. Although construction practices 

may differ, earthquake-resistant design is 

becoming increasingly common througho'•t the 

world, and many buildings are designed on the 

basis of principles used in the United States. 

Thus, important damaging earthquakes should be 

investigated regardless of their location in the 

world. 
The communication process 

The ultimate aim of the USGS seismic 

hazards and risk program is effective utilization of all of its research products by the 

various user groups. Publication of a map 

follows years of research and data gathering, 

but it is not an end in itself. Both during and 

following the research and data-gathering phase, 

extensive communication must take place between 

the researchers and potential users to insure 

maximum benefit in earthquake hazard reduction. 

The USGS plans to continue to seek ways to 

improve communication between producers and 

users of seismic-hazards and risk-assessment 

information. Communication methods, such as 

workshops and cluster meetings, that have worked 

well in the past will be continued and strengthened. Methods that have proven ineffective 

(such as simply transmitting a map or report) 

will be replaced with more workable methods. 

The emphasis will be placed on improving communications in what may be the two most critical 

periods of time: (1) the planning period before 

the research starts, and (2) the period of time 

immediately following the distribution of a 

research product. Emphasis will also be placed 

on developing a procedure to introduce change. 

The goal of implementing USGS research products 

at all levels requires timely and effective 

communication. 

REFERENCES CITED 

Algermissen, S. T., 1969, Seismic risk studies 

in the United States: World Conference on 

Earthquake Engineering, 4th, Santiago, 

Chile, Proceedings, v. 1, 14 P• 

1973, The problem of seismic zoning, in 

Wright, R., Kramer, S., and Culver, C~ 

eds., Building practices for disaster mitigation: U.S. Department of Commerce, 

National Bureau of Standards, Building 

Science ser. 46, p. 112-125. 

1978, Earthquake hazard studies and 

building codes; Hays, w. W., ed.: in Communicating earthquake hazards reduction 

information: u.s. Geological Survey OpenFile Report 78-933, p. 281-287. 

Algermissen, S. T., Hopper, M. G., Campbell, K., 

Rinehart, w. A., and Perkins, D. M. (geological and seismological portion); 

Steinbrugge, K. v., Lagorio, H. J., Moran, 

D. F., Cluff, L. s., Degenkolb, H. J., Duke, 

C. M., Gates, G. 0., Jacobson, D. w., Olson, 

R. A., and Allen, C. R. (engineering 

analysis portion), 1973, A study of earthquake losses in the Los Angeles, California, 

area: u.s. Department of Commerce, National 

Oceanic and Atmospheric Administration, 331 

P• 

28 

Algermissen, S. T., McGrath, M. B., and Hanson, 

S. L., 1978, Development of a technique for 

the rapid estimation of earthquake losses: 

u.S. Geological Survey Open-File Report 78-

440, 98 P• 

Algermissen, S. T., and Perkins, D. M., 1976, A 

probabilistic estimate of maximum acceleration in rock in the contiguous United 

States: U.S. Geological Survey Open-File 

Report 76-416, 45 P• 

Algermissen, s. T., Rinehart, W. A., and Dewey, 

J., (geologic and seismological portion), 

Steinbrugge, K. v., Lagorio, H. H., 

Degenkolb, H. J., Cluff, L. S., HcClure, 

F. E., Scott, s., and Gordon, R. F., (engineering analysis portion), 1972, A study of 

earthquake losses in the San Francisco Bay 

area: u.s. Dept. Commerce, National Oceanic 

and Atmospheric Administration, 220 P• 

Algermissen, S. T., Steinbrugge, K. v., and 

Lagorio, H. L., 1978, Estimation of earthquake losses to buildings (except single 

family dwellings): U.S. Geological Survey 

Open-File Report 78-441, 161 P• 

Applied Technology Council, 1978, Tentative 

provisions for the development of seismic 

regulations for buildings: ATC-3-06, 

514 P• (Available from NatiC'nal Bureau of 

Standards, Special Publication 510, 

Washington, D.C.) 

Borcherdt, R. D., ed., 1975, Studies for seismic 

zonation of the San Francisc? Bay region: 

U.S. Geological Survey Professional Paper 

941-A, 102 P• 

Buck, Richard, 1978, The Puget Sonnd Earthquake 

Preparedness Project; in Hays, w. w., ed.; 

Communicating earthquake hazards reduction 

information: U.S. Geological Survey OpenFile Report 78-933, p. 97-119. 

Bucknam, R. C., and Anderson, R. E., 1979, 

Estimation of fault-scarp ages from a scarpheight-slope-angle relationship: Geology, 

v. 7, P• 11-14. 

Cornell, C. A. , 1968, Engineering seismic risk 

analysis: Seismological Society of America 

Bulletin, v. 58,' p. 1583-1606. 

Departments of the Army, the Navy, and the Air 

Force, 1973, Seismic design for buildings, 

TMS-809-10 NAV FAC P-355, AFM 88-3, SO p. 

(Available from Superintendent of Documents, 

U.S. Government Printing Office, Washington, 

D.C.) 

Department of Housing and Urban Development, 

1976, A methodology for seismic design and 

construction of single-family dwellings HUD-
PDR-248-1, 649 P• (Available from Dept. of 

Housing and Urban Development, Washington, 

D.C.) 

Dewey, J. w., 1979, A consumer's guide to 

instrumental methods for determination of 

hypocenters; in Hatheway, A. w., and 

McClure, C. R. ;-Jr., eds.; Geology in the 

siting of nuclear power plants; Geological 

Society of America Reviews in Engineering 

Geology, v. 4, p. 175-200. 

Donovan, N. C., 1973, A statistical evaluation 

of strong motion data including the February 

9, 1971 San Fernando earthquake: World 

Conference on Earthquake Engineering, 5th, 

Rome, Italy, Proceedings, v. 2, paper 155, 

110 P• 

Espinosa, A. F., ed., 1976, The Guatemalan 

earthquake of February 4, 1976, a preliminary report: U.S. Geological Survey Professional Paper 1002, 90 P• 

General Services Administration, 1978, Design 

guidelines, earthquake resistance of 

buildings, v. 1, 56 p. (available from GSA 

Business Service Center, Denver, CO). 

Hadley, J. B., and Devine, J. F., 1974, 

Seismotectonic map of the eastern United 

States: U.S. Geological Survey Miscellaneous Field Studies Map MF-620. 

Hamilton, R. M., 1978, Earthquake Hazards Reduction Program - Fiscal year 1978, Studies 

supported by the U.S. Geological Survey: 

U.S. Geological Survey Circular 780, 36 P• 

Hays, w. w., 1979a, Uncertainties in seismic 

input and site response: American Society 

of Civil Engineering, Conference on Civil 

Engineering and Nuclear Power, Boston, 

Mass., Proceedings, v. 2, P• 10-40. 

1979b, Summary report on USGS workshop on 

---se-ismic risk, October 25-27, 1978: Earthquake Engineering Research Institute 

Newsletter, v. 13, no. 2, P• 64-69. 

Hays, w. w., Algermissen, s. T., Espinosa, 

A. F., Perkins, D. M., and Rinehart, w. A., 

197 5, Guidelines for developing design 

earthquake response spectra: U.S. Army 

Construction Engineering Research Laboratory 

Technical Report M-114, 369 P• 

Heyl, A. v., and McKeown, F. A., 1978, 

nary seismotectonic map of 

Mississippi Valley and environs: 

Geological Survey Miscellaneous 

Studies Map MF-1011, 1:500,000. 

PrelimiCentral 

u.s. 

Field 

Hopper, M. G., Langer, C. J., Spence, w. J., 

Rogers, A. M., and Algermissen, S. T. 

(geological and seismological portions); 

Olsen, B. C., Lagorio, H. J., and 

Steinbrugge, K. v. (engineering ar~lysis 

portion), 1975, A study of earthquake losses 

in the Puget Sound, Washington, area: U.S. 

Geological Survey Open-File Report 75-375, 

298 P• 

Howard, K. A., Aaron, J. M., Brabb, E. E., 

Brock, M. R., Gower, H. D., Hunt, S. J., 

Milton, D. J., Muehlberger, w. R., Nakata, 

J. K., Plafker, G., Prowell, D. C., Wallace, 

R. E., and Witkind, I. J., 1977, Preliminary 

map of young faults in the United States as 

a guide to possible fault activity: U.S. 

Geological Survey Miscellaneous Field 

Studies Map MF-916, 1:5,000,000 and 

1:7,500,000. 

29 

!wan, w. D., 1978, Strong 'motion earthquake 

instrument arrays: California Institute of 

Technology, International Workshop on Strong 

Motion Instrument Arrays, May 2-5, 1978, 

Honolulu, Hawaii, Proceedings, 102 P• 

Karnik, V., and Algermissen, S. T., 1978, 

Seismic zoning, in The assessment and mitigation of earthquake risk: Paris, France, 

UNESCO, P• 1-47. 

Kockelman, W. J., 1978, Communicating rf~search 

products developed by the San Francisco Bay 

Region Environment and Resources Planning 

Study, in Hays, w. w., ed., Communicating 

earthquake hazards reduction infornation: 

U.S. Geological Survey Open-File Report 78-

933, P• 307-334. 

MacCabe, M. P., 1979, Earthquake Hazards Reduction Program, Project summaries--fiscal year 

197 8: U. S. Geological Survey Op~~n-File 

Report 79-387, 113 p. 

Mann, 0. C., 1978, Regional earthquake planning 

in the Mississippi-Arkansas-Tennessee area, 

in Hays, W. w., ed., Communicating earthquake hazards reduction information: U.S. 

Geological Survey Open-File Report 78-933, 

P• 134-156. 

McGuire, R. K., 1979, Adequacy of simple probability models for calculating felt-::~-haking 

hazard, using the Chinese earthquake 

catalog: Seismological Society of America 

Bulletin, v. 69, no. 3, P• 781-801. 

National Science Foundation and Departrr~nt of 

the Interior-u.s. Geological Survey, 1976, 

Earthquake prediction and hazard mitigation 

options for USGS and NSF pr~grams: 

Washington, D. C., U.s. Government P-:-inting 

Office, Superintendent of Documents, 76 P• 

Office of Emergency Preparedness, 1972, D•saster 

preparedness: Report to Congress of the 

United States, 3 volumes, 364 P• 
Office of Science and Technology Policy, 1978, 

Earthquake hazards reduction--Issues for an 

implementation plan: Washington, D. C., 

Executive Office of the President, 231 P• 

Olson, R. A., 1978, An evaluation of the seismic 

safety element requirement in California, in 

Hays, W. W., ed., Communicating earthquake 

hazards reduction information: U.S. 

Geological Survey Open-File Report 78-933, 

P• 68-93. 

Perkins, Jeanne, 1978, ABAG's use of research 

products developed in the San Francisco Bay 

Region Study in Regional Planning, in Hays, 

W. W., ed., Communicating earthquake~azards 

reduction information: U.S. Geological 

Survey Open-File Report 78-933, p. 335-349. 

Rankin, D. w., 1977, Studies related to the 

Charleston, South Carolina, earthquake of 

1886, a preliminary report: u.s. Geological 

Survey Professional Paper 1028, 204 p. 

Rinehart, W. A., Algermissen, S. T., and 

Gibbons, M., 1976, Estimation of earthquake 

losses to single-family dwellings: U.S. 

Geological Survey Open-File Report 76-156, 

185 P• 

Rogers, A.M., Algermissen, S. T., Hays, w. W., 

Perkins, D. , (geological and seismological 

portion); Van Strien, D. 0., Hughes, H. c., 

Hughes, R. C., Lagorio, H. J., and 

Steinbrugge, K. V., (engineering analysis 

portion), 1976, A study of earthquake losses 

in the Salt Lake City, Utah, area: U.S. 

Geological Survey Open-File Report 76-89, 

357 P• 

Schnabel, P. 

erations 

western 

Society 

516. 

B., and Seed, H. B., 1973, Accelin rock for earthquakes in the 

United States: Seismological 

of America Bulletin, v. 62, p. 501-

Stover, C. W., 1977, Seismicity map of the 

conterminous United States and adjacent 

areas: U.S. Geological Survey Miscellaneous 

Field Studies Map MF-812, 1:5,000,000. 

Uniform Building Code, 1973, International 

Conference of Building Officials, Whittier, 

Calif., (updated every three years) 704 p. 

United States Geological Survey and National 

Science Foundation, 1976, Earthquake prediction and hazard mitigation options for USGS 

and NSF programs: Washington, D. c., U.s. 

Government Printing Office, Superintendent 

of Documents, 76 p. 

United States Geological Survey and National 

Oceanic and Atmospheric Administration, 

1971, The San Fernando, California earthquake of February 9, 1971: U.S. Geological 

Survey Professional Paper 733, 254 p. 

30 

Veterans Administration, 1973, Earthquake resistant design requirements for VA hospital 

facilities: Handbook H-08-8, 36 P• (available from Veterans Admin., Washington, D.C.) 

Whitman, R. V., 1978, Effective peak acceleration: International Conferenc~ on Microzonation, 2nd, San Francisco, Calif., v. 3, 

P• 1247-1256. 

Wiggins, J. H., 1973, The risk inbalance in 

current public policies: Proceedings of 

Symposium on Risk Acceptanc~ and Public 

Policy, Denver, Colo., International System 

Safety Society, p. 1-35. 

Youd, T. L., and Perkins, D. M., 1978, Mapping 

liquefaction-induced ground failure potential: American Society of Civil Engineering, Journal of Geotechnical Engineering 

Division, v. 104, p. 433-446. 

Young, Eleanor, 1978, The seismic safety 

element, Santa Clara County, California, 

Hays, w. w., ed., in Communicating earthquake hazards reduction infor11ation: U.S. 

Geological Survey Open-File Feport 78-933, 

P• 47-67. 

Appendix A--Glossary 

These terms are intended to denote common 

usage, but the definitions do not represent a 

consensus. 

Accelerogram. The record from an accelerometer 

showing acceleration as a function of time. 

Acceptable risk. A specification cf the acceptable number of fatalities due to the earthquake threat, or an equivalent statement in 

terms of buildings. Residual risk is a 

preferable term. 

Active fault. A fault is active if, because of 

its present tectonic setting, it can undergo 

movement from time to time in the immediate 

geologic future. This active state exists 

independently of the geologists' ability to 

recognize it. Geologists have used a number 

of characteristics to idertify active 

faults, such as historic seismicity or 

surface faulting, geologically recent 

displacement inferred from topography or 

stratigraphy, or physical conne'?.tion with an 

active fault. However, not enough is known 

of the behavior of faults to assure identification of all active faults by such 

characteristics. Selection of the criteria 

used to identify active faults for a particular purpose must be influenced by the 

consequences of fault movement on the engineering structures involved. 
Attenuation. (1) A decrease of signal amplitude 

during transmission; (2) a reduction in 

amplitude or energy with or without change 

of waveform; or (3) a decrease in seismic 

signal strength with distance, which depends 

not only on geometrical spreading but also 

may be related to those physical characteristics of the transmitting medium that cause 

absorption and scattering. 

Base shear. A seismic-design parameter in the 

--Uniform Building Code that is a horizontal 

load on a structure and is determined by a 

product of a seismic coefficient, an 

exposure factor, and the weight of the 

structure. 

Body waves. Waves propagated in the interior of 

---a body; that is, compression and shear 

waves, the P and S waves of seismology. 

Capable fault. A fault along which future surface displacement is possible, especially 

during the lifetime of the project under 

consideration. 

Design earthquake. The largest earthquake that 

has such a high probability of occurrence 

based on studies of historic seismicity and 

structural geology that it is appropriate to 

design a structure to withstand it. Ground 

shaking of the design earthquake might be 

exceeded, but the probability of this 

happening is considered to be small. 

Design spectra. Spectra appropriate for earthquake-resistant design purposes. Design 

spectra are typically smooth curves that 

have been modified from a family of spectra 

of historic earthquakes to take account of 

features peculiar to a geographic region and 

a particular site. Design spectra do not 

include the effect of soil-structure interaction. 

Design time history. One of a family of time 

histories which produces a response spectrum 

that envelopes the smooth design spectrum, 

for a selected value of damping, at all 

periods. 

Earthquake hazards. The probability that 

natural events accompanying an earthquake 

such as ground shaking, ground failure, surface faulting, tectonic deformation, and 

inundation, which may cause damage and loss 

of life, will occur at a site during a 

specified exposure time. See Earthquake 

risk. 

Earthquake risk. The probability that social or 

economic---consequences of earthquakes, 

expressed in dollars or casualties, will 

equal or exceed specified values at a site 

during a specified exposure time. 

31 

Earthquake waves. Elastic waves propagating in 

the earth, set in motion by a sudden change 

such as faulting of a portion of the earth. 

Effective peak acceleration. The peak ground 

acceleration after the ground-motion record 

has been filtered to remove the very high 

frequencies that have little influenc.e upon 

structural response. 

Effective peak velocity. The peak ground 

velocity after the ground-motion record has 

been filtered to remove high frequencies. 

Epicenter. The point on the Earth 1 s surface 

vertically above the point where th~ first 

rupture and the first earthquake motion 

occur. 

Exceedance probability. The probability (for 

example, 10 percent) over some period of 

time that an event will generate a level of 

ground shaking greater than some sp~cified 

level. 

Exposure time. The period of time (for example, 

50 years) that a structure is exposed to the 

earthquake threat. The exposure time is 

sometimes chosen to be equal to the design 

lifetime of the structure. 

Fault. A fracture or fracture zone in th~ earth 

-along which displacement of the two sides 

relative to one another has occurred parallel to the fracture. See Active, Capable, 

Normal, Thrust, and Strike-slip faults. 

Focal depth. The vertical distance betw~en the 

--h-ypocenter and the Earth's surface in an 

earthquake. 

Ground response, motion, ~ seismic response. A 

general term, including all aspe~ts of 

motion; for example, particle acceleration, 

velocity, or displacement; stress and strain 

from a nuclear explosion, an earthquake, or 

another energy source. 

Intensity. A numerical index describing the 

effects of an earthquake on the Earth's surface, on man, and on structures built by 

him. The scale in common use in the United 

States today is the Modified Mercalli scale 

of 1931 with intensity values indicated by 

Roman numerals from I to XII. The narrative 

descriptions of each intensity value are 

summarized below. 

I. Not felt--or, except rarely under especially favorable circumstances. Under 

certain conditions, at and outside the 

boundary of the area in which a great 

shock is felt: sometimes, birds, 

animals, reported uneasy or disturbed; 

sometimes dizziness or nausea experienced; sometimes trees, stru~tures, 

liquids, bodies of water, may sway--

doors may swing, very slowly. 
II. Felt indoors by few, especially on upper 

floors, or by sensitive, or nervous 

persons. Also, as in grade I, but 

often more noticeably: sometimes 

hanging objects may swing, especially 

when delicately suspended; sometimes 

trees, structures, liquids, bodies of 

water, may sway, doors may swing, very 

slowly; sometimes birds, animals, 

reported uneasy or disturbed; sometimes 

dizziness or nausea experienced. 

III. Felt indoors by several, motion usually 

rapid vibration. Sometimes not recognized to be an earthquake at first. 

Duration estimated in some cases. 

Vibration like that due to passing of 

light, or lightly loaded trucks, or 

heavy trucks some distance away. 

Hanging objects may swing slightly. 

Movements may be appreciable on upper 

levels of tall structures. Rocked 

standing motor cars slightly. 

IV. Felt indoors by many, outdoors by few. 

Awakened few, especially light 

sleepers. Frightened no one, unless 

apprehensive from previous experience. 

Vibration like that due to passing of 

heavy or heavily loaded trucks. Sensation like heavy body striking building 

or falling of heavy objects inside. 

Rattling of dishes, windows, doors; 

glassware and crockery clink and clash. 

Creaking of walls, frame, especially in 

the upper range of this grade. Hanging 

objects swung, in numerous instances. 

Disturbed liquids in open vessels 

slightly. Rocked standing motor cars 

noticeably. 

V. Felt indoors by practically all, outdoors 

by many or most; outdoors direction 

estimated. Awakened many, or most. 

Frightened few--slight excitement, a 

few ran outdoors. Buildings trembled 

throughout. Broke dishes, glassware, 

to some extent. Cracked windows--in 

some cases, but not generally. Overturned vases, small or unstable 

objects, in many instances, with occasional fall. Hanging objects, doors, 

swing generally or considerably. 

Knocked pictures against walls, or 

swung them out of place. Opened, or 

closed, doors, shutters, abruptly. 

Pendulum clocks stopped, started or ran 

fast, or slow. Moved small objects, 

furnishings, the latter to slight 

extent. Spilled liquids in small 

amounts from well-filled open containers. Trees, bushes, shaken 

slightly. 

VI. Felt by all, indoors and outdoors. 

Frightened many, excitement general, 

some alarm., many ran outdoors. Awak32 

ened all. Persons made to move 

unsteadily. Trees, b·Jshes, shaken 

slightly to moderately. Liquid set in 

strong motion. Small bells rang--

church, chapel, school, etc. Damage 

slight in poorly built buildings. Fall 

of plaster in small amo·•nt. Cracked 

plaster somewhat, esp~cially fine 

cracks chimneys in some instances. 

Broke dishes, glassware, in considerable quantity, also some windows. 

Fall of knick-knacks, books, pictures. 

Overturned furniture in m'lny instances. 

Moved furnishings of mod.erately heavy 

kind. 

VII. Frightened all--general alarm, all ran 

outdoors. Some, or many, found it 

difficult to stand. Noticed by persons 

driving motor cars. Trees and bushes 

shaken moderately to strongly. Waves 

on ponds, lakes, and rnnning water. 

Water turbid from mud stirred up. 

Incaving to some extent of sand or 

gravel stream banks. Rang large church 

bells, etc. Suspended objects made to 

quiver. Damage negligible in buildings 

of good design and construction, slight 

to moderate in well-built ordinary 

buildings, considerable in poorly built 

or badly designed buildings, adobe 

houses, old walls (especially where 

laid up without mortar), spires, etc. 

Cracked chimneys to considerable 

extent, walls to some extent. Fall of 

plaster in considerable to large 

amount, also some stucco. Broke 

numerous windows, furniture to some 

extent. Shook down loosened brickwork 

and tiles. Broke weak chimneys at the 

roof-line (sometimes damE-.ging roofs). 

Fall of cornices from tot~Ters and high 

buildings. Dislodged bricks and 

stones. Overturned hea'-y furniture, 

with damage from breaking. Damage considerable to concrete irrigation 

ditches. 

VIII. Fright general--alarm approaches panic. 

Disturbed persons driving motor cars. 

Trees shaken strongly--branches, 

trunks, broken off, esp~cially palm 

trees. Ejected sand and mud in small 

amounts. Changes: temporary, permanent; in flow of springs a"'d wells; dry 

wells renewed flow; in tPmperature of 

spring and well waters. Damage slight 

in structures (brick) built especially 

to withstand earthquakes. Considerable 

in ordinary substantial buildings, partial collapse: racked, tumbled down, 

wooden houses in some casP.sj threw out 

panel walls in frame structures, broke 

off decayed piling. Fall of walls. 

Cracked, broke, solid ston~ walls seriously. Wet ground to some extent, also 
ground on steep slopes. TWisting, 

fall, of chimneys, columns, monuments, 

also factory stacks, towers. Moved 

conspicuously, overturned, very heavy 

furniture. 

IX. Panic general. Cracked ground conspicuously. Damage considerable in 

(masonry) structures built especially 

to withstand earthquakes: Threw out of 

plumb some wood-frame houses built 

especially to withstand earthquakes; 

great in substantial (masonry) buildings, some collapse in large part; or 

wholly shifted frame buildings off 

foundations, racked frames; serious to 

reservoirs; underground pipes sometimes 

broken. 

X. Cracked ground, especially when loose and 

wet, up to widths of several inches; 

fissures up to a yard in width ran 

parallel to canal and stream banks. 

Landslides considerable from river 

banks and steep coasts. Shifted sand 

and mud horizontally on beaches and 

flat land. Changed level of water in 

wells. Threw water on banks of canals, 

lakes, rivers, etc. Damage serious to 

dams, dikes, embankments. Severe to 

well-built wooden structures and 

bridges, some destroyed. Developed 

dangerous cracks in excellent brick 

walls. Destroyed most masonry and 

frame structures, also their foundations. Bent railroad rails slightly. 

Tore apart, or crushed endwise, pipe 

lines buried in earth. Open cracks and 

broad wavy folds in cement pavements 

and asphalt road surfaces. 

XI. Disturbances in ground many and widespread, varying with ground material. 

Broad fissures, earth slumps, and land 

slips in soft, wet ground. Ejected 

water in large amounts charged with 

sand and mud. Caused sea-waves 

("tidal" waves) of significant magni~ 

tude. Damage severe to wood-frame 

structures, especially near shock 

centers. Great to dams, dikes, embankments often for long distances. Few, 

if any (masonry) structures remained 

standing. Destroyed large well-build 

bridges by the wrecking of supporting 

piers: or pillars. Affected yielding 

wooden bridges less. Bent railroad 

rails greatly, and thrust them endwise. 

Put pipe lines buried in earth completely out of service. 

XII. Damage total--practically all works of 

construction damaged greatly or 

destroyed. Disturbances in ground 

great and varied, numerous shearing 

cracks. Landslides, falls of rock of 

significant character, slumpin~: of 

river banks, etc., numerous and extensive. Wrenched loose, tore off, large 

rock masses. Fault slips in firm rock, 

with notable horizontal and vertical 

offset displacements. Water chan~els, 

surface and underground, disturbei and 

modified greatly. Dammed lakes, 

produced waterfalls, deflected rivers, 

etc. Waves seen on ground surfaces 

(actually seen, probably, in some 

cases). Distorted lines of sight and 

level. Threw objects upward into the 

air. 

Liquefaction. Temporary transformatio'"l of 

unconsolidated materials into a fluid ~~ss. 

Magnitude. A quantity characteristic of the 

total energy released by an earthquake, as 

contrasted to intensity that describes its 

effects at a particular place. Professor 

C. F. Richter devised the logarithmic scale 

for local magnitude (ML) in 1935. Magnitude 

is expressed in terms of the motion that 

would be measured by a standard type of 

seismograph located 100 km from the epicenter of an earthquake. Several other 

magnitude scales in addition to Mr. are in 

use; for example, body-wave magnitude (mb) 

and surface-wave magnitude (Ms), which 

utilize body waves and surface waves, and 

local magnitude (ML). The scale is open 

ended, but the largest known earthquake to 

have occurred had Ms magnitudes near 8.9. 

Model. A concept from which one can c~duce 

----effects that can then be compared to observation, which assists in developir~ an 

understanding of the significance of the 

observations. The model may be conceptual, 

physical, or mathematical. 

33 

Moment. The seismic moment M0 =vUA contains 

information on the rigidity (~) of the 

elastic medium in the source region, average 

dislocation (ii), and area (A) of faulting. 

It determines the amplitude of the longperiod level of the spectrum of ground 

motion. 

Normal fault. A fault in which the hangin~ wall 

~s gone down relative to the footwall. 

Probability of occurrence. The annual r-11te of 

occurrence!of a hazard. 

Region. A geographical area surrounding and 

including the site sufficiently large to 

contain all the features related to a particular earthquake hazard. 

Response spectrum. 

series of simple 

different natural 

The peak 

harmonic 

period 

response of a 

oscillators of 

when sul: jected 
mathematically to a particular earthquake 

ground motion. The response spectrum may be 

plotted as a curve on tripartite logarithmic 

graph paper showing the variations of the 

peak spectral acceleration, displacement, 

and velocity of the oscillators as a function of vibration period and damping. 

Return period. The average period of time or 

recurrence interval between events causing 

ground shaking that exceeds a particular 

level at a site; the reciprocal of annual 

probability of exceedance. A return period 

of 475 years means that, on the average, a 

particular level of ground motion will be 

exceeded once in 475 years. 

Risk. See Earthquake risk. 

Rock. Any solid rock either at the surface or 

----underlying soil having a shear-wave velocity 

>2,500 ft/s (765 m/s) at small (0.0001 percent) strains. 

Seismic source zones. Areas of spatially homogene~rthquake activity. 

Seismotectonic province. A geographic area 

characterized by similarity of geological 

structure and earthquake characteristics. 

Standard deviation. A measure of the scatter of 

n measurements of a quantity ~' with 

respect to the mean, X. 

Stress drop. Ao=o 0-o 1 , where o 0 is the initial 

stress before the earthquake and a is the 

stress after the earthquake. For ~he 1971 

San Fernando, Calif., earthquake, the 

average initial stress is estimated to have 

been about 100 bars and the stress drop to 

have been about 60 bars. Stress drop is 

believed to control the high-frequency 

spectral content of earthquake ground 

motions, whereas seismic moment controls the 

low frequencies. 

Stress (effective). In modeling an earthquake, 

the effective stress is defined as a=a -a , 

where o0 is the stress before the earthquate 

and of is the frictional stress acting to 

resist the fault slip. 

Strike-slip fault. A fault in which movement is 

principally horizontal. The San Andreas 

fault is strike-slip. 

Strong motion. Ground motion of sufficient 

amplitude to be of engineering interest in 

the evaluation of damage due to earthquakes. 

Surface waves. Seismic energy that travels 

along or near the surface; includes 

Rayleigh and Love waves. 

34 

Thrust fault. An inclined fracture along which 

the rocks above the fracture h~ve apparently 

moved up with respect to those beneath. The 

1964 Alaska and 1971 San Fe:rnando earthquakes occurred on thrust faults. 

Upper-bound earthquake. The hypothetical earthquake that is considered to be the most 

severe reasonably possible on the basis of 

comprehensive studies of historic seismicity 

and structural geology. 

Appendix B 

PROJECTS, GRANTS, AND CONTRACTS F'"JNDED IN FY 79 

EARTHQUAKE HAZARDS REDUCTION PROGRAM, 

U.S. GEOLOGICAL SURVEY 

This list includes commitmerts made prior 

to 17 November 1978. 

I. EARTHQUAKE HAZARDS STUDIES 

I.A. EARTHQUAKE POTENTIAL 

I.A.1. Tectonic framework, Quaternary geology, 

and active faults 

I.A.1. California 

VERTICAL CRUSTAL DEFORMATION IN f0UTHERN CALIFORNIA AND THE PACIFIC STATES, R. 0. Castle, 

U.S. Geological Survey, Branch of Earthquake 

Tectonics and Risk, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2482. 

COASTAL TECTONICS OF CALIFORNIA, OREGON, AND 

WASHINGTON, K. R. Lajoie, U.S. Geological 

Survey, Branch of Ground Motion and Faulting, 

345 Middlefield Road, Menlo Par'~, California 

94025, (415) 323-8111, ext. 2642. 

Southern California 

EARTHQUAKE HAZARDS GEOLOGIC MAPPING OF THE SAN 

ANDREAS FAULT ZONE, LOS ANGELES COUNTY, CALIFORNIA, A. G. Barrows, State of California, 

Division of Mines and Geology, 107 South 

Broadway, Room 1065, Los Angeles, California 

90012. 

SURFACE FAULT TRACES AND HISTORIC EARTHQUAKE 

EFFECTS NEAR LOS ALAMOS VALLEY, SANTA BARBARA 

COUNTY, CALIFORNIA, G. E. Brogan, ~··:'lodward-Clyde 

Consultants, P.O. Box 1149, Orang,~, California 

92668, (714) 799-2011. 

SURFICIAL QUATERNARY DEPOSITS AND TECTONICS OF 

THE WESTERN MOJAVE DESERT REGION, D. B. Burke, 

U.S. Geological Survey, Branch of Ground Motion 

and Faulting, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2048. 
ACTIVE FAULTS AND RECENT TECTONIC DEFORMATION, 

SOUTHERN CALIFORNIA, M. M. Clark, U.S. Geological Survey, Branch of Ground Motion and 

Faulting, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2591. 

GEOMORPHIC STUDIES OF POST-PLEISTOCENE DEFORMATION ALONG THE SAN ANDREAS FAULT, WEST-cENTRAL 

TRANSVERSE RANGES, CALIFORNIA, J. C. Crowell, 

University of California, Department of Geological Sciences, Santa Barbara, California 93106, 

(805) 961-3224. 

GEOLOGIC INVESTIGATION OF THE SAN MIGUEL FAULT 

ZONE, BAJA, CALIFORNIA, R. G. Gastil, San Diego 

State University, Department of Geological 

Sciences, San Diego, California 92182, (714) 

286-6211. 

QUATERNARY TECTONICS, OFFSHORE LOS ANGELES-SAN 

DIEGO AREA, H. G. Greene, U.S. Geological 

Survey, Branch of Pacific-Arctic Geology, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 7047. 

AEROMAGNETIC INTERPRETATION OF THE WESTERN 

TRANSVERSE RANGES, CALIFORNIA, Andrew Griscom, 

U.S. Geological Survey, Branch of Regional 

Geophysics, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2268. 

EARTHQUAKE HAZARDS ASSOCIATED WITH THE VERDUGOEAGLE ROCK AND BENEDICT CANYON FAULT ZONES, LOS 

ANGELES COUNTY, CALIFORNIA, R. L. Hill, State of 

California, Division of Mines and Geology, 107 

South Broadway, Room 1065, Los Angeles, California 90012. 

TECTONIC GEOMORPHOLOGY AND POSSIBLE FUTURE 

SEISMIC ACTIVITY OF THE CENTRAL VENTURA BASIN, 

CALIFORNIA, E. A. Keller, University of California, Department of Geological Sciences, Santa 

Barbara, California 93106. 

RECENCY AND CHARACTER OF FAULTING OFFSHORE FROM 

METROPOLITAN SAN DIEGO, CALIFORNIA, M. P. 

Kennedy, State of California, Division of Mines 

and Geology, 107 South Broadway, Room 1065, Los 

Angeles, California 90012, (714) 452-2751. 

TECTONICS OF THE EASTERN TRANSVERSE RANGES AND 

QUATERNARY GEOLOGY OF THE UPPER SANTA ANA 

VALLEY, CALIFORNIA, D. M. Morton, U.S. Geological Survey, Branch of Western Environmental 

Geology, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2353. 

SEISHIC HAZARD STUDY OF THE WESTERN PORTION OF 

THE GARLOCK FAULT, SOUTHERN CALIFORNIA, C. M. 

Payne, Fugro, Inc., 3777 Long Beach Blvd., Long 

Beach, California 90807, (213) 595-6611. 

BASEMENT ROCKS ALONG THE SAN ANDREAS FAULT 

SYSTEM, D. C. Ross, U.S. Geological Survey, 

Branch of Earthquake Tectonics and Risk, 345 

35 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 2341. 

TECTONICS OF THE SALTON TROUGH AND VICINITY, 

R. V. Sharp, U.s. Geological Survey, Brar~.h of 

Ground Motion and Faulting, 345 Middlefield 

Road, Menlo Park, California 94025, (415) 323-

8111, ext. 2596. 

STUDIES OF LATE HOLOCENE BEHAVIOR OF TPE SAN 

ANDREAS FAULT SYSTEM--SAN JUAN BAUTISTA TO THE 

SALTON SEA, K. E. Sieh, California Institute of 

Technology, Division of Geological and Pla~etary 

Sciences, Pasadena, California 91125, (213) 795-

6811, ext. 2108. 

CLASSIFICATION AND MAPPING OF QUATERNARY SEDIMENTARY DEPOSITS FOR PURPOSES OF SEISMIC ZONATION, SOUTH COASTAL LOS ANGELES BASIN, ORANGE 

COUNTY, E. C. Sprotte, State of California, 

Division of Mines and Geology, Departme'lt of 

Conservation, 107 South Broadway, Room 1065, Los 

Angeles, California 90012. 

QUATERNARY GEOLOGY OF THE LOS ANGELES BASIN, 

J. C. Tinsley, u.s. Geological Survey, Branch of 

Western Environmental Geology, 345 Middlefield 

Road, Menlo Park, California 94025, (415) 323-

8111, ext. 2037. 

GEOLOGIC INVESTIGATION OF THE MARINE TERRA\.ES OF 

THE SAN SIMEON REGION AND PLEISTOCENE ACTIVITY 

ON THE SAN SIMEON FAULT ZONE, CALIFORNIA, G. E. 

Weber, Weber and Associates, 127 Pryce Street, 

Santa Cruz, California 95060. 

SUBSURFACE GEOLOGY OF THE SAN GABRIEL, H1LSER, 

AND SIMI-SANTA ROSA FAULTS, TRANSVERSE RANGES, 

CALIFORNIA, R. S. Yeats, Oregon State University, Department of Geology, Corvallis, Oregon 

97330, (502) 754-2484. 

SUBSURFACE GEOLOGY OF POTENTIALLY ACTIVE FAULTS 

IN THE COASTAL REGION BETWEEN GOLETA AND 

VENTURA, CALIFORNIA, R. S. Yeats, Oregon State 

University, Department of Geology, Corvallis, 

Oregon 97330, (502) 754-2484. 

TECTONICS OF THE WESTERN TRANSVERSE RANGES, 

R. F. Yerkes, u.s. Geological Survey, Branch of 

Western Environmental Geology, 345 Middlefield 

Road, Menlo Park, California 94025, (415) 323-

8111, ext. 2350. 

Northern California 

TECTONIC FRAMEWORK AND SEISMIC ZONATION OF THE 

SAN FRANCISCO BAY REGION, E. E. Brabb, U.S. 

Geological Survey, Branch of Western Environmental Geology, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2203. 

HOLOCENE BEHAVIOR OF THE SAN ANDREAS FAULT--SAN 

JUAN BAUTISTA TO POINT ARENA, CALIFORNIA, W. R. 
Cotton, Foothill-DeAnza Community College District, 12345 El Monte Road, Los Altos Hills, 

California 94022, (415) 948-8590. 

GEOPHYSICS OF THE SAN FRANCISCO BAY REGION, 

Andrew Griscom, U.s. Geological Survey, Branch 

of Regional Geophysics, 345 ~1iddlefield Road, 

Menlo Park, California 94025, (415) 323-8111, 

ext. 2268. 

NEOTECTONICS OF THE SAN FRANCISCO BAY REGION, 

D. G. Herd, u.s. Geological Survey, Branch of 

Western Environmental Geology, 345 Middlefield 

Road, Menlo Park, California 94025, (415) 323-

8111, ext. 2870. 

RELATION OF SEISMICITY TO REGIONAL GEOLOGY IN 

NORTHERN CALIFORNIA, W. P. Irwin, U.S. Geological Survey, Branch of Earthquake Tectonics and 

Risk, 345 Middlefield Road, Menlo Park, California 94025, (415) 323-8111, ext. 2065. 

MOVEMENT AND DEFORMATION ON THE SOUTHERN FOOTHILLS FAULT SYSTEM, CALIFORNIA, Richard 

Schweickert, Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 

10964. 

I.A.1.b. Western United States 

(excluding California) 

LATE QUATERNARY FAULTING AND LATE CENOZOIC 

TECTONICS IN SOUTHWESTERN UTAH, R. E. Anderson, 

U.S. Geological Survey, Branch of Earthquake 

Tectonics and Risk, Denver Federal Center, 

Denver, Colorado 80225, (303) 234-5109. 

LATE QUATERNARY FAULTING IN NORTHWESTERN UTAH, 

R. C. Bucknam, u.s. Geological Survey, Branch of 

Earthquake Tectonics and Risk, Denver Federal 

Center, Denver, Colorado 80225, (303) 234-5089. 

REGIONAL GEOLOGICAL STRUCTURE OF THE PUGET SOUND 

BASIN, H. D. Gower, U.S. Geological Survey, 

Branch of Western Environmental Geology, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 2352. 

SURFICIAL GEOLOGY OF THE SALT LAKE VALLEY, 

R. D. Miller, u.s. Geological Survey, Branch of 

Engineering Geology, Denver Federal Center, 

Denver, Colorado 80225, (303) 234-2960. 

STRATIGRAPHY OF PRE-VASHON QUATERNARY SEDIMENTS 

APPLIED TO THE EVALUATION OF A PROPOSED MAJOR 

TECTONIC STRUCTURE IN ISLAND COUNTY, WASHINGTON, 

Pamela Palmer, State of Washington, Department 

of Natural Resources, P. 0. Box 168, Olympia, 

Washington 98501. 

GEOCHEMICAL CRITERIA TO AID IN ~PPING THE 

MARINE LIMIT IN THE PUGET LOWLAND, D. R. Pevear, 

U.S. Geological Survey, Branch of Western Environmental Geology, Western Washington University, Department of Geology, Bellingham, 

Washington 98225, (206) 733-1848 or 676-3590. 

36 

SOUTHERN ALASKA SEISMOTECTONICS, George Plafker, 

U.s. Geological Survey, Branch of Alaskan 

Geology, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2201. 

QUATERNARY GEOLOGY OF THE WASATC'·l FRONT, W. E. 

Scott, u.s. Geological Survey, Branch of Central 

Environmental Geology, Denver Federal Center, 

Denver, Colorado 80225, (303) 234-5215. 

GEOLOGIC MAPPING OF THE VISTA AND STEAMBOAT 

7 1/2-MINUTE QUADRANGLES, NEVADA, D. Trexler, 

State of Nevada, Nevada Bureau of Mines, Mackay 

School of Mines, University of Nevada, Reno, 

Nevada 89507, (702) 784-6691. 

I.A.1.c. Eastern United States 

LATE TERTIARY AND QUATERNARY TECTONIC DEFORMATION OF SHORELINES IN THE SOUTH~ASTERN UNITED 

STATES, B. W. Blackwelder, U. f.. Geological 

Survey, Branch of Paleontology and Stratigraphy, 

Room 501, National Museum, Wa~hington, D.C. 

20244, (202) 343-5488. 

SEISMOTECTONICS OF THE NORTHEASTERN UNITED 

STATES, w. H. Diment, u.s. Geological Survey, 

Branch of Earthquake Tectonics and Risk, 12201 

Sunrise Valley Drive, Reston, Virginia 22092, 

(703) 860-6520. 

TECTONIC HISTORY OF EASTERN OZARK UPLIFT, E. E. 

Glick, u.s. Geological Survey, Branch of Central 

Environmental Geology, Denver Federal Center, 

Denver, Colorado 80225, (303) 234-3353. 

TECTONIC ORIGIN OF EASTERN UNITED STATES SEISMICITY, R. M. Hamilton, u.s. Geolcgical Survey, 

Branch of Earthquake Tectonics ard Risk, 12201 

Sunrise Valley Drive, Reston, Virginia 22092, 

(703) 860-7684. 

GEOPHYSICS OF THE NEW ~DRID SEISMIC ZONE, 

T. G. Hildenbrand, u.s. Geological Survey, 

Branch of Regional Geophysics, r·:mver Federal 

Center, Denver, Colorado 80225, (303) 234-5464. 

ENGINEERING GEOLOGY OF METROPOLITAN BOSTON, 

C. A. Kaye, u.s. Geological Survey, Branch of 

Engineering Geology, 150 Causeway Street, Room 

1304, Boston, Massachusetts 02110, (617) 223-

7200. 

QUATERNARY STRATIGRAPHY AND BEDRCCK STRUCTURAL 

FRAMEWORK, GILES COUNTY, VIRGINIA, W. L. Newell, 

U.S. Geological Survey, Branch of Eastern Environmental Geology, 12201 Sunrise Valley Drive, 

Reston, Virginia 22092, (703) 860-6420. 

RELATION OF SEISMICITY TO GEOLOGIC STRUCTURES IN 

NORTHEASTERN UNITED STATES AND GEC~OGIC STUDIES 

OF THE ~PO FAULT ZONE, NEW YORK, N. M. 

Ratcliffe, u.s. Geological Survey, Branch of 

Eastern Environmental Geology, 12201 Sunrise 

Valley Drive, Reston, Virginia 220~2, (703) 860-

6404. 
MISSISSIPPI VALLEY SEISMOTECTONICS, D. P. Russ, 

U.S. Geological Survey, Branch of Earthquake 

Tectonics and Risk, Denver Federal Center, 

Denver, Colorado 80225, (303) 234-5065. 

GEOPHYSICS OF THE NORTHEASTERN UNITED STATES FOR 

EARTHQUAKE STUDIES, Robert Simpson, U.S. Geological Survey, Branch of Regional Geophysics, 

Denver Federal Center, Denver, Colorado 80225, 

(303) 234-2623. 

NORUMBEGA FAULT ZONE, EASTERN MAINE, D. R. 

Wones, u.s. Geological Survey, Branch of Eastern 

Environmental Geology, 4044 Derring Hall, 

Virginia Polytechnical Institute, Blacksburg, 

Virginia 24061, (703) 951-5980. 

I.A.1.d. National 

NEOTECTONIC SYNTHESIS OF THE UNITED STATES, 

C. M. Wentworth, U.S. Geological Survey, Branch 

of Western Environmental Geology, 345 Middlefield Road, Menlo Park, California 94025, (415) 

323-8111, ext. 2474. 

SEISMOGENIC ZONES OF THE UNITED STATES, J. I. 

Ziony, u.s. Geological Survey, Branch of Earthquake Tectonics and Risk, 345 Middlefield Road, 

Menlo Park, California 94025, (415) 323-8111, 

ext. 2944 or 2214. 

I.A.2. Earthquake recurrence and dating of 

fault movements 

CHARACTERISTICS OF ACTIVE FAULTS, GREAT BASIN: 

R. C. Bucknam, U.S. Geological Survey, Branch of 

Earthquake Tectonics and Risk, Denver Federal 

Center, Denver, Colorado 80225, (303) 234-5089. 

TEPHROCHRONOLOGY, CENTRAL UNITED STATES, G. A. 

Izett, u.s. Geological Survey, Branch of Central 

Environmental Geology, Denver Federal Center, 

Denver, Colorado 80225, (303) 234-2835. 

A NEW METHOD OF ALLUVIAL AGE DATING BASED ON 

PROGRESSIVE WEATHERING, WITH APPLICATIONS TO THE 

TIME-HISTORY OF FAULT ACTIVITY IN SOUTHERN 

CALIFORNIA, Barclay Kamb, California Institute 

of Technology, Division of Geology and Planetary 

Science, Pasadena, California 91109, (213) 795-

6811, ext. 2109. 

CORRELATING AND DATING QUATERNARY SEDIMENTS BY 

AMINO ACIDS, K. A. Kvenvolden, U.S. Geological 

Survey, Branch of Pacific-Arctic Geology, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 7150. 

PALEOMAGNETIC DATING OF LATE NEOGENE DEPOSITS IN 

THE ATLANTIC COASTAL PLAIN WITH APPLICATION TO 

DATING TECTONIC DEFORMATION, SOUTHEASTERN UNITED 

STATES, J. C. Liddicoat, Lamont-Doherty Geological Observatory of Columbia University, 

Palisades, New York 10964. 

37 

CORRELATION AND SEMIQUANTITATIVE AGE-DATING OF 

SOILS, WESTERN UNITED STATES, D. E. Marchand, 

U.S. Geological Survey, Branch of Western Environmental Geology, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2009. 

DETERMINATION OF THE MAGNITUDE AND DATE OF DIPSLIP FAULTING BY DISCORDANCE IN SETS OF MEAN SEA 

LEVEL CURVES, \v. S. Newman, Queens College of 

City University of New York, Department of Earth 

and Environmental Sciences, Flushing, New York 

11367. 

QUATERNARY DATING TECHNIQUES, K. L. Pierce, U.S. 

Geological Survey, Branch of Central Environmental Geology, Denver Federal Center, r•'!nver, 

Colorado 80225, (303) 234-2737. 

URANIUM TREND DATING OF SOILS, J. N. Rcshol t, 

U.S. Geological Survey, Branch of I so tope 

Geology, Denver Federal Center, Denver, Cclorado 

80225, (303) 234-4201. 

TRENCHING STUDIES OF THE SAN ANDREAS FAULT 

BORDERING WESTERN ANTELOPE VALLEY, SCUTHERN 

CALIFORNIA, D. J. Rust, University of California, Department of Geological Sciences, Santa 

Barbara, California 93106. 

TEPHROCHRONOLOGY, WESTERN UNITED STATES, A. M. 

Sarna-Wojciki, u.s. Geological Survey, Br~qch of 

Western Environmental Geology, 345 Middlefield 

Road, Menlo Park, California 94025, (415) 323-

8111, ext. 2745. 

PALEOSEISMIC INDICATORS IN SEDIMENTS, J. D. 

Sims, u.S. Geological Survey, Branch of Earthquake Tectonics and Risk, 345 Middlefiel~ Road, 

Menlo Park, California 94025, (415) 323-8111, 

ext. 2252. 

QUATERNARY REFERENCE CORE, CLEAR LAKE, CALIFORNIA, J. D. Sims, u.s. Geological Survey, 

Branch of Earthquake Tectonics and Risk, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 2252. 

STUDIES OF EARTHQUAKE RECURRENCE INTERVALS ON 

THE WASATCH FAULT, F. H. Swan, Woodward-Clyde 

Consultants, Three Embarcadero Center, Suite 

700, San Francisco, California 94111. 

TECTONIC ANALYSIS OF ACTIVE FAULTS, R. E. 

Wallace, u.s. Geological Survey, Office of 

Earthquake Studies, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2751. 

I.B. EARTHQUAKE EFFECTS 

I.B.1. Ground Motion 

REVISION OF THE MODIFIED MERCALLI IN~ENSITY 

SCALE AND SEISMICITY AND RELATED DATA FOR HAZARD 
ANALYSIS, S. T. Algermissen, U.S. Geological 

Survey, Branch of Earthquake Tectonics and Risk, 

Denver Federal Center, Denver, Colorado 80225, 

(303) 234-4014. 

REGIONAL AND NATIONAL SEISMIC HAZARD AND RISK, 

S. T. Algermissen, U.S. Geological Survey, 

Branch of Earthquake Tectonics and Risk, Denver 

Federal Center, Denver, Colorado 80225, (303) 

234-4014. 

A NEW ATTEMPT AT SEISMIC ZONING MAPS FOR 

SOUTHERN CALIFORNIA, C. R. Allen, California 

Institute of Technology, Seismological Laboratory, Pasadena, California 91109, (213) 795-

6811, ext. 2903. 

PHYSICAL CONSTRAINTS ON SOURCE OF GROUND MOTION, 

D. J. Andrews, u.s. Geological Survey, Branch of 

Ground Motion and Faulting, 345 Middlefield 

Road, Menlo Park, California 94025, (415) 323-

8111, ext. 2752. 

THREE-DIMENSIONAL MODELING OF NEAR-FIELD GROUND 

MOTION, Ralph Archuleta, U.S. Geological Survey, 

Branch of Ground Motion and Faulting, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 2161. 

INTERACTIVE DATA PROCESSING CENTER FOR GROUND 

MOTION STUDIES, L. M. Baker, U.S. Geological 

Survey, Branch of Ground Motion and Faulting, 

345 Middlefield Road, Menlo Park, California 

94025, (415) 323-8111, ext. 2881. 

STATISTICAL FAULT MODELS FOR GROUND MOTION 

MODELING, David Boore, U.S. Geological Survey, 

Branch of Ground Motion and Faulting, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 2755. 

DEVELOPMENT AND ACQUISITION OF INSTRUMENTATION 

FOR GROUND MOTION STUDIES, R. D. Borcherdt, U.S. 

Geological Survey, Branch of Ground Motion and 

Faulting, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2755. 

DYNAMIC SOIL BEHAVIOR, A. T. F. Chen, U.S. 

Geological Survey, Branch of Engineering 

Geology, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2605. 

SEISMIC ATTENUATION STUDIES OF THE UNITED 

STATES, A. F. Espinosa, U.S. Geological Survey, 

Branch of Earthquake Tectonics and Risk, 345 

Middlefield Road, Menlo Park, California 94025, 

(303) 234-5077. 

REGIONAL INVESTIGATIONS OF NEAR-SURFACE SHEAR 

WAVE VELOCITIES, J. F. Gibbs, U.S. Geological 

Survey, Branch of Ground Motion and Faulting, 

345 Middlefield Road, Menlo Park, California 

94025, (415) 323-8111, ext. 2030. 

38 

NUMERICAL METHODS FOR ESTIMATI~G RESPONSE OF 

ALLUVIAL BASINS, S. T. Harding, U.s. Geological 

Survey, Branch of Ground Motion and Faulting, 

Denver Federal Center, Denver, Colorado 80225, 

(303) 234-5090. 

GROUND RESPONSE IN THE SALT LAKE CITY REGION, 

w. w. Hays, u.s. Geological Survey, Branch of 

Ground Motion and Faulting, Denver Federal 

Center, Denver, Colorado 80225, (303) 234-4029. 

GROUND MOTION PREDICTION AT SELECTED STRONG 

MOTION SITES, W. B. Joyner, U~S. Geological 

Survey, Branch of Ground Motion and Faulting, 

345 Middlefield Road, Menlo Park, California 

94025, (415) 323-8111, ext. 2754. 

SEISMIC DATA FOR GROUND RESPONSE MAPPING IN THE 

SALT LAKE CITY REGION, K. W. King:, U.s. Geological Survey, Branch of Ground Motion and Faulting, Denver Federal Center, Denver, Colorado 

80225, (303) 234-5087. 

MICROZONATION OF THE MEMPHIS, TINNESSEE AREA, 

w. D. Kovacs, Purdue University, fchool of Civil 

Engineering, West Lafayette, Indi.:na 47907. 

CALCULATIONS OF STRONG MOTION AND LOCAL FIELDFAR FIELD RELATIONSHIPS FOR THE APRIL 29, 1965, 

PUGET SOUND, WASHINGTON, EARTHQUAKE, C. A. 

Langston, Pennsylvania State Unive.rsity, Department of Geosciences, University Park, Pennsylvania 16802. 

METHODS OF PROBABILISTIC SEISMIC HAZARD ASSESSMENT, R. K. McGuire, U.S. Geolo~ical Survey, 

Branch of Earthquake Tectonics and Risk, Denver 

Federal Center, Denver, Colorado 80225, (303) 

234-2874. 

EARTHQUAKE INTENSITY AND RECUFRENCE, R. D. 

Nason, u.s. Geological Survey, Branch of Ground 

Motion and Faulting, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2760. 

COMPUTER BASED MAPPING--SAN FRANCISCO BAY AREA, 

D. A. Olmstead, Association of Bay Area Governments, Hotel Claremont, Berkeley, California 

94705. 

DATA PROCESSING SUPPORT FOR GROUND MOTION 

STUDIES, R. B. Park, U.S. Geological Survey, 

Branch of Ground Motion and Faulting, Denver 

Federal Center, Denver, Colorado 80225, (303) 

234-5070. 

PROBABILISTIC SEISMIC HAZARD OF TID: OUTER CONTINENTAL SHELF, D. M. Perkins, U.f, Geological 

Survey, Branch of Earthquake Tectorics and Risk, 

Denver Federal Center, Denver, Colorado 80225, 

(303) 234-2832. 

THE INFLUENCE OF LOCAL SITE GEOLOGY ON STRONG 

GROUND MOTIONS, H. E. Read, Systems, Science and 
Software, P.O. Box 1620, La Jolla, California 

92038, (714) 453-0060. 

GROUND RESPONSE IN 'THE LOS ANGELES VICINITY, 

A. M. Rogers, u.s. Geological Survey, Branch of 

Ground Motion and Faulting, Denver Federal 

Center, Denver, Colorado 80225, (303) 234-2869. 

GROUND MOTION PREDICTIONS FOR THE LOS ANGELES 

BASIN FROM A MAJOR SAN ANDREAS EARTHQUAKE, 

Joel Sweet, Del Mar Technical Associates, P.O. 

Box 1083, Del Mar, California 92014. 

GEOTECHNICAL INVESTIGATIONS FOR GROUND MOTION 

STUDIES, R. E. Warrick, U.S. Geological Survey, 

Branch of Ground Motion and Faulting, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 2757. 

DIFFRACTION OF WAVES BY THREE-DIMENSIONAL 

SURF ACE TOPOGRAPHIES AND SUB SURF ACE IRREGULARITIES, H. L. Wong, University of Southern California, University Park, Los Angeles, California 

90007. 

GROUND MOTION PREDICTION AND EASTERN U.S. EARTHQUAKE MONITORING, F. T. Wu, State University of 

New York, Department of Geological Sciences, 

Binghamton, New York 13901. 

I.B.2. Ground failure (including liquefaction 

and landslides) 

STUDY OF LIQUEFACTION IN THE NOVEMBER 23, 1977 

EARTHQUAKE IN SAN JUAN PROVINCE, ARGENTINA, 

Ignacio Arango, Woodward-Clyde Consultants, 

Three Embarcadero Center, Suite 700, San Francisco, California 94111, (415) 956-7070. 

DEVELOPMENT OF TECHNIQUES FOR EVALUATING SEISMIC 

HAZARDS ASSOCIATED WITH EXISTING CREEPING LANDSLIDES AND OLD DAMS, R. E. Goodman, University 

of California, Department of Civil Engineering, 

Berkeley, California 94720, (415) 642-5525. 

EARTHQUAKE-INDUCED LANDSLIDES, E. L. Harp, U.S. 

Geological Survey, Branch of Engineering 

Geology, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2529. 

GROUND FAILURES CAUSED BY HISTORIC EARTHQUAKES, 

D. K. Keefer, u.s. Geological Survey, Branch of 

Engineering Geology, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2557. 

GROUND FAILURE RELATED TO THE NEW MADRID EARTHQUAKES, s. F. Obermeier, u.s. Geological Survey, 

Branch of Engineering Geology, 12201 Sunrise 

Valley Drive, Reston, Virginia 22092, (703) 860-

6469. 

EVALUATION OF THE CONE PENETROMETER FOR LIQUEFACTION HAZARD ASSESSMENT, G. R. Martin, Fugro, 

39 

Inc., 3777 Long Beach Blvd., Long Beach, California 90807, (213) 595-6611. 

EARTHQUAKE INDUCED LIQUEFACTION AND SUBSIDENCE 

OF GRANULAR MEDIA, S. Nemat-Nasser, Northw~stern 

University, Department of Civil Engine~ring, 

Evanston, Illinois 60201. 

INFLUENCE OF GROUND MOTION ON GROUND FAILURE, 

R. C. Wilson, U.S. Geological Survey, Branch of 

Engineering Geology, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2967. 

EXPERIMENTAL MAPPING OF LIQUEFACTION POTENTIAL, 

L. T. Youd, u.s. Geological Survey, Brar~h of 

Engineering Geology, 345 Middlefield Road, Menlo 

Park, California 94025, (415) 323-8111, ext. 

2529. 

PRELIMINARY ASSESSMENT OF LIQUEFACTION POTENTIAL 

IN AND NEAR SAN JUAN, PUERTO RICO, L. T. Youd, 

u.S. Geological Survey, Branch of Engineering 

Geology, 345 Middlefield Road, Menlo Park, 

California 94025, (415) 323-8111, ext. 2529. 

I.B.3 Surface faulting and other earthquakerelated hazards 

STATISTICAL ANALYSIS AND GEOMETRY OF SURFACE 

FAULTING, M. G. Bonilla, u.s. Geological Survey, 

Branch of Ground Motion and Faulting, 345 

Middlefield Road, Menlo Park, California 94025, 

(415) 323-8111, ext. 2245. 

EARTHQUAKE-RELATED HAZARDS IN AND NEAR HILO, 

HAWAII, Jane Buchanan-Banks, U.S. Geological 

Survey, Branch of Engineering Geology, Hawaiian 

Volcano Observatory, Hawaii National Park, 

Hawaii, Hawaii 06718, (808) 967-7328. 

EARTHQUAKE HAZARDS, UPPER COOK INLET - SUSITNA 

LOWLAND REGION, ALASKA, Oscar Ferrians, U.S. 

Geological Survey, Branch of Alaskan Ge-1logy, 

345 Middlefield Road, Menlo Park, California 

94025, (415) 323-8111, ext. 2247. 

I.B.4. Post-earthquake studies 

MOTAGUA FAULT, GUATEMALA, AFTERSLIP STUDY, 

R. C. Bucknam, u.s. Geological Survey, Brc:nch of 

Earthquake Tectonics and Risk, Denver Federal 

Center, Denver, Colorado 80225, (303) 234~5089. 

SEISMOLOGICAL FIELD INVESTIGATIONS, C. J. 

Langer, u.s. Geological Survey, Branch of Earthquake Tectonics and Risk, Denver Federal Center, 

Denver, Colorado 80225, (303) 234-5091. 

POST-EARTHQUAKE FIELD INVESTIGATIONS, R. A. 

Page, u.s. Geological Survey, Office of Earthquake Studies, 345 Middlefield Road, Menlc Park, 

California 94025, (415) 323-8111, ext. 24f1. 
I.C. EARTHQUAKE LOSSES 

AN ALTERNATING MARKOVIAN PROCESS FOR EARTHQUAKE 

OCCURRENCES, H. C. Shah, Stanford University, 

Department of Civil Engineering, Stanford, 

California 94305, (415) 497-4128. 

A STOCHASTIC AND BAYESIAN MODEL FOR HAZARD 

MAPPING AND FOR ESTIMATING EARTHQUAKE LOSSES, 

H. c. Shah, Stanford University, Department of 

Civil Engineering, Stanford, California 94305, 

(415) 497-4128. 

DEVELOPMENT OF DATA BASES, P~RAMETERS, AND 

METHODS FOR CONVERTING GROUND MOTION TO EXPECTED 

DOLLAR LOSS FOR HIGH-RISE BUILDINGS, R. E. 

Scholl, URS/John A. Blume and Associates, 130 

Jessie Street, San Francisco, California 94105, 

(415) 397-2525. 

40 

DEVELOPMENT OF AN EY~OSURE MODEL FOR THE UNITED 

STATES BUILDING WEALTH AND ANNUAL ECONOMIC LOSS 

CONSEQUENCES OF THE VARIOUS SEISMIC RISK MAPS, 

J. H. Wiggins, J. H. Wiggins Compe.ny, 1650 South 

Pacific Coast Highway, Redondo Beech, California 

90277, (213) 378-0257. 

<t: U.S. GOVERNMENT PRINTING CFFICE: 1979-677-129/15