U.S. GEOL()GICAL SURVBV CIRCULAR 1066 

Tecumseh • s Prophecy: 

Preparing for the 

Next New Madrid 

Earthquake 
COVER 

Woodcut of ~~scene of the Great Earthquake in the West II (Our First 

Century: One Hundred Great and Memorable Events, 1877, p. 220). 

Published with permission of the State Historical Society of Missouri, 

Columbia, Mo. 

ABOUT THE TITLE 

According to legend, (Penick, 1981, p. 123), the Shawnee Indian chief 

Tecumseh traveled south in 1811 from his village of Tippecanoe on the 

Wabash River in an attempt to recruit supporters. At a town of Creek 

Indians near the site of Montgomery, Ala., Tecumseh declared that they 

would know he was sent by the Great Spirit because, upon leaving, he 

would go to Detroit, stamp his foot on the ground, and shake down all 

their houses. Tecumseh left. The Creeks counted the days; on the morning they had estimated for his arrival in Detroit, the earth began to shake, 

and houses fell down. It was the first of the New Madrid, Mo., earthquakes, 

which were centered about 250 mi away in the Mississippi Valley. 
"The Great Earthquake of New Madrid 1811-1812." Published with 

permission of the State Historical Society of Missouri, Columbia, Mo. 
TECUMSEH ·s PROPHECY: 

PREPARING FOR THE NEXT NEW MADRID EARTHQUAKE 
Tecumseh•s Prophecy: 

Preparing for the 

Next New Madrid 

Earthquake 

A PLAN FOR AN INTENSIFIED STUDY OF THE 

NEW MADRID SEISMIC ZONE 

Edited by ROBERT M. HAMILTON and 

ARCH C. JOHNSTON 

With contributions by the participants in the New 

Madrid Seismic Zone Workshop, November 15-16, 

1989, Memphis, Tennessee 

U.S. GEOLOGICAL SURVEY CIRCULAR 1066 
DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, Jr., Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

Any use of trade, product, or firm names in this publication is for descriptive 

purposes only and does not imply endorsement by the U.S. Government 

First printing 1990 

Second printing 1991 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1990 

Free on application to the 

Books and Open-File Reports Section 

U.S. Geological Survey 

Federal Center, Box 25425 

Denver, CO 80225 

Library of Congress Cataloging in Publication Data 

Tecumseh's prophecy. 

(U.S. Geological Survey circular ; 1066) 

"With contributions by the participants in the New Madrid Seismic Zone 

Workshop, November 15-16, 1989, Memphis, Tennessee." 

Includes bibliographical references. 

Supt. of Docs. No.: I 19.4/2:1066 

I. Earthquakes-Missouri-New Madrid Region. 2. SeismologyMissouri-New Madrid Region. I. Hamilton, Robert Morrison, 

1936- . II. Johnston, Arch C. Ill. Series. 

QE535.2.U6T43 1990 551.2'2'09778985 90-3151 
CONTENTS 

Summary 1 

Introduction 2 

The Danger: Seismic Risk Assessment 5 

Introduction 5 

Seismicity 8 

Regional Tectonic Setting 9 

Earthquake Effects 11 

Potential Losses 12 

The Response: Preparedness and Mitigation 15 

The Plan: Preparing for the Next New Madrid Earthquake 17 

Introduction 17 

Purpose 18 

Goals 18 

Activities 18 

Management and Coordination 27 

Conclusions 27 

References Cited 28 

Appendix: New Madrid Seismic Zone Workshop Participants 30 

FIGURES 

1-5. Maps showing: 

1. Seismicity of the Central and Eastern United States and adjacent parts of 

Canada showing earthquakes of magnitude 3 or greater from 1568 to 

1987 4 

2. Areas of intensities VI and VII for two great earthquakes of about magnitude 8 and two major damaging earthquakes 6 

3. Regional distribution of estimated Modified Mercalli intensities that would 

result from a recurrence of the 1811-12 earthquake series in the New 

Madrid seismic zone 7 

4. Seismicity and major structural features of the New Madrid seismic 

zone 10 

5. Seismicity and major geologic structures in the most active part of the New 

Madrid seismic zone 11 

6. Photograph showing trees tilted by a landslide along the Chickasaw Bluffs 

near Reelfoot Lake in northeastern Tennessee 13 

7. Aerial photograph taken in 1959 near Portageville, Mo. 14 

8. Diagram illustrating the goals of community actions in implementing loss 

reduction measures 16 

9-11. Maps showing: 

9. Current regional seismic network in the New Madrid seismic zone 19 

10. U.S. National Seismic Network stations in the Central United States 20 

11. Current strong-ground-motion stations in the New Madrid seismic 

zone 21 

TABLES 

1. Damaging earthquakes in the New Madrid region 3 

2. Earthquake probability estimates for the New Madrid seismic zone 8 

Tecumseh's Prophecy: Preparing for the Next New 

Madrid Earthquake 

A Plan for an Intensified Study of the New Madrid Seismic Zone 

Edited by Robert M. Hamilton 1 and Arch C. johnston2 

Summary 

Four earthquakes of magnitude near 8 and thousands 

of aftershocks struck the central Mississippi Valley in the 

winter of 1811-12. New Madrid, Mo., the largest settlement in the area at the time, and the surrounding land were 

devastated. The New Madrid region continues to have the 

highest level of seismicity in the United States east of the 

Rocky Mountains. Earthquakes of estimated magnitude 6.4 

and 6.8 occurred in 1843 and 1895, respectively: statistical 

analyses indicate that earthquakes of magnitude greater than 

6.0 are expected at least once per century. 

The potential losses from future earthquakes of magnitude 6 or greater in the New Madrid region are expected 

to be large because of ( 1) the high population density 

(Memphis, St. Louis, and many moderate-sized agricultural 

and industrial towns), (2) the large number of structures and 

industrial and transportation facilities, which generally were 

not designed to withstand earthquakes, (3) the great thickness and extent of poorly consolidated sedimentary rocks, 

which are weak foundation material and which amplify 

ground vibrations, and ( 4) the large area that would be 

affected by damaging ground motion (about 10 times larger 

than the area affected by a California earthquake of comparable size). A future great earthquake (magnitude 8.0 or 

larger) has the potential to cause damages in the tens of 

billions of dollars and deaths in the thousands unless 

communities reduce their vulnerability through improved 

preparedness and increased mitigation measures. A magnitude 6.5 earthquake could cause about $3.6 billion in losses 

to housing. 

1 U.S. Geological Survey, Reston, VA 22092. 2 Center for Earthquake Research and Information/Memphis State 

University, Memphis, TN 38152. 

Manuscript approved for publication March 13. 1990. 

Loss of life and damage from earthquake0 can be 

reduced through a variety of measures, all of which could 

be implemented in the New Madrid region. Tl1e most 

relevant actions include: 

• Improving building construction requirements and 

siting practices through better codes and regulations. 

• Reducing building vulnerability by strengtl,~ning or 

demolishing hazardous buildings, particularly unreinforced masonry buildings, and strengthening 

foundations. This action should begin with schools, 

hospitals, and emergency centers. 

• Increasing awareness and utilization of ezrthquake 

mitigation measures through public educrtion and 

training of those who would implement t'le measures. 

• Improving public response to earthquake disasters 

through preparedness planning involving realistic 

scenarios of destructive earthquakes. 

Mitigation measures such as these would b~ implemented by the local, State, and Federal Government agencies that are responsible for emergency preparedness and 

building regulation and by private and industrial groups. 

Such measures were in place, to a significant extent, and 

substantially reduced the losses that might otherv,ise have 

occurred as a result of the Lorna Prieta earthqua~e in the 

San Francisco Bay area on October 17, 1989. Impl ~menting 

mitigation measures in the New Madrid region has lagged 

far behind implementation in California, primarily because 

earthquakes occur less frequently in the New Madrid 

region, and the public is therefore less awaF~ of the 

destructive potential. However, the lower frequency of 

destructive New Madrid earthquakes is offset by tl'~ greater 

area that they affect and by the greater vulnerability of 

structures and lifeline systems in the region. 

Mitigation measures cannot be implemented effectively without reliable information about the likely locations, sizes, frequency, and probable effects of future 

Summary 
earthquakes. Because such information is currently incomplete for the New Madrid region, some of the major goals of 

an intensified study should be to improve the information 

that would be used as the basis for mitigation. 

An intensified study of the New Madrid seismic zone 

should focus on five goals: 

1. Implementing earthquake-hazard mitigation measures. 

2. Improving preparedness for earthquakes of magnitude 6 or larger. 

3. Establishing a modern seismic network in the New 

Madrid seismic zone to monitor the sizes, locations, and characteristics of the earthquakes and to 

determine the nature of the ground motions that 

they generate. 

4. Locating faults that could generate destructive 

earthquakes, determining the recurrence rates of 

earthquakes, and delineating areas of potential 

damage. 

5. Improving seismic-risk assessments. 

Depending on the options selected and the pace of the 

study, these recommendations could be implemented at a 

funding level of $5 to $10 million annually for 5 years, at 

which time progress should be reviewed and a new plan 

prepared. An intensified study would be conducted under 

the auspices of the National Earthquake Hazards Reduction 

Program (NEHRP), which involves the Federal Emergency 

Management Agency (FEMA), the U.S. Geological Survey 

(USGS), the National Science Foundation (NSF), and the 

National Institute of Standards and Technology (NIST). An 

intensified study should include the full scope of NEHRP 

activities. Generally, mitigation measures are the responsibility of FEMA, NSF, and NIST, and research is the 

responsibility of USGS and NSF. Coordination of the study 

would be facilitated by establishing a coordinating committee and by holding an annual workshop to review recent 

developments and progress and to recommend priorities. 

INTRODUCTION 

The New Madrid seismic zone in the central Mississippi Valley poses the greatest earthquake danger in the 

United States east of the Rocky Mountains. Four earthquakes of about magnitude 8 (table 1) occurred in the 

seismic zone in the winter of 1811-12, and the area 

continues to experience the highest level of seismicity in the 

central and eastern parts of the Nation (fig. 1). Concern 

about the probable effects of future New Madrid earthquakes convinced Congress to direct the U.S. Geological 

Survey to prepare a plan for an intensified study of the New 

Madrid seismic zone. The first step in preparing the plan 

was to convene a workshop of about 70 academic, private, 

and State and Federal Government experts (appendix) in 

Memphis, Tenn., on November 15-16, 1989. to prepare 

recommendations for such an intensified study. This publication summarizes the results of that worksho'J. 

Earthquake studies in the United States an" conducted 

mainly under the auspices of the National Earthquake 

Hazards Reduction Program (NEHRP), which was authorized by the Earthquake Hazards Reduction Act of 1977 and 

its subsequent amendments and reauthorizations. The Federal agencies that participate in NEHRP and th~ir areas of 

responsibility are as follows: 

• Federal Emergency Management Agency 

(FEMA): Lead agency of NEHRP; planning, coordination, and program review; annual report to 

Congress; opportunities for participatior by States, 

localities, private organizations, and individuals; 

assistance to State and local governments to implement comprehensive earthquake-hazarc reduction 

programs; improved seismic design and construction techniques and standards for application; public 

education and awareness programs; and coordination of Federal response to catastrophic earthquakes. 

• U.S. Geological Survey (USGS): Earthquake 

potential; earthquake prediction; earthq'Iake information and data services; earthquake hazards and 

risk assessments; strong-ground-motion data and 

estimates; and technical assistance in fostering 

implementation of loss-reduction measures. 

• National Science Foundation (NSF): Earthquake 

engineering research; earthquake preparedness and 

emergency response research; social, economic. and 

political impacts; earthquake research information; 

and fundamental studies on the sources and mechanisms of earthquakes and on earth struc+ure. 

• National Institute of Standards and Technology 

(NIST): Seismic design and constructio'1 standards 

and Federal construction practices. 

Representatives from the four NEHRP Federal agencies 

attended the workshop. The recommendations ir this report 

cover the full scope of responsibilities under NEHRP. 

NEHRP not only involves a partnership among four 

Federal agencies but also encompasses participation by 

scientists, engineers, and others from universitie~. State and 

local government agencies, private groups, and other Federal agencies. University scientists, in particular, have 

played an important role in NEHRP, a role that developed 

from their pioneering studies of U.S. earthquakes. Federal 

Government agencies that are not formally part of NEHRP 

also have contributed significantly to earthquake studies in 

the New Madrid region. Most importantly. the U.S. 

Nuclear Regulatory Commission (NRC) has supported a 

comprehensive scientific research effort that included 

expansion of regional seismic network coverage during the 

late 1970's and early 1980's. Recently, the NRC has been 

gradually withdrawing financial support for tl'~ regional 

seismic networks; support is scheduled to end in 1992. In 

2 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
Table 1. Damaging earthquakes in the New Madrid region (data from Nuttli (1983), 

Coffman and others (1982), and Johnston (1990)) 

[M is moment magnitude (Hanks and Kanamori, 1979), which is proportional to the logarithm of the product 

of slip on a fault, the area that slipped, and the rigidity. All magnitudes referred to in the text are moment 

magnitudes. mb is body-wave magnitude. MMio is maximum Modified Mercalli intensity] 

Lat Long 

Date (oN) (oW) 

1811/12116 .............. 36 90 

1811/12/16 .............. 36 90 

1812/01/23 .............. 36.3 89.6 

1812/02/07 .............. 35.5 89.6 

1838/06/09 .............. 38.5 89 

1843/01104 .............. 35.5 90.5 

1857/10/08 .............. 38.7 89.2 

1865/08/17 .............. 35.5 90.5 

1891109/27 .............. 38.3 88.5 

1895/04/12 .............. 37.0 89.4 

1899/04/29 .............. 38.8 87.0 

1903/11104 .............. 36.9 89.3 

1905/08/21 .............. 36.8 89.6 

1909/05/26 .............. 42.5 89.0 

1909/07/19 .............. 40.2 90.0 

1909/09/27 .............. 39.5 87.4 

1917/04/09 .............. 38.1 90.2 

1922111127 .............. 37.5 88.5 

1923/10/28 .............. 35.5 90.4 

1925/04/27 .............. 38.3 87.6 

1927/05/07 .............. 35.7 90.6 

1931/12/16 .............. 34.1 89.8 

1962/02/02 .............. 36.6 89.7 

1963/03/03 .............. 36.7 90.0 

1965/10/21. ............. 37.8 91.1 

1968/11109 .............. 38.0 88.5 

1969/01101. ............. 34.8 92.6 

1970/11/17 .............. 35.9 89.9 

1972/09/15 .............. 41.6 89.4 

1976/03/25 .............. 35.6 90.5 

1982/01/21 .............. 35.2 92.2 

1987/06/10 .............. 38.7 88.0 

1986, the NRC and the USGS signed an agreement to 

establish the U.S. National Seismic Network to satisfy 

NRC's seismologic data needs. The U.S. Army Corps of 

Engineers has conducted a variety of important studies of 

the fluvial deposits of the Mississippi Valley and maintains 

instruments at Corps facilities to record strong ground 

motion from earthquakes. The Department of Veterans' 

Affairs has installed instruments to record strong ground 

motion in some of its hospitals in the region. The NSF 

established the National Center for Earthquake Engineering 

Research, which conducts various studies and operates 

instruments in the the New Madrid seismic zone. 

State organizations and universities have taken some 

very important initiatives in addressing earthquake hazards. 

Monitoring of the New Madrid seismic zone was begun by 

seismologists at Saint Louis University when they installed 

instruments at Cape Girardeau, Mo., and Little Rock, Ark., 

in 1929. The university continues to monitor seismicity 

M mb MMI Locality 0 

8.2 7.2 11 New Madrid, Mo. 

7.8 7.0 11 ...... do ...... 

8.1 7.1 10-11 ...... do ...... 

8.3 7.4 11-12 ...... do ...... 

5.1 5.0 7-8 Southern Illinois 

6.4 6.0 8 Marked Tree, Ark. 

5.1 5.4 7 Southern Illinois 

5.2 5.3 7 Southeastern Missouri 

5.5 5.8 7 Southern Illinois 

6.8 6.2 9 Charleston, Mo. 

4.3 4.6 7 Vincennes, Ind. 

5.0 4.9 7 Southeastern Missouri 

4.9 4.8 7 Mississippi Valley 

5.2 5.1 7 Illinois 

4.3 4.6 7 ...... do ...... 

4.7 4.8 7 Indiana-Illinois border 

4.9 5.0 6-7 Eastern Missouri 

4.4 4.5 6-7 Illinois 

4.3 4.5 7 Marked Tree, Ark. 

4.9 4.8 7 Indiana-Illinois border 

4.8 4.8 7 Northeastern Arkansas 

4.1 4.7 6-7 Northern Mississippi 

4.2 4.2 6 New Madrid, Mo. 

4.7 4.7 6 Southern Missouri 

4.6 4.9 6 Eastern Missouri 

5.4 5.5 7 South-central Illinois 

4.3 4.4 6 Central Arkansas 

4.1 4.4 6 Blytheville, Ark. 

4.1 4.4 6 Northern Illinois 

4.6 5.0 6 Northeastern Arkansas 

4.4 4.7 6 North-central Arkansas 

5.0 4.9 6 Southeastern Illinois 

through networks funded by the USGS and the NRC. 

Faculty members, particularly the late Otto Nuttli, have 

spent considerable time informing the public of the hazard 

posed by the New Madrid seismic zone. Professor Nuttli, 

beginning in the late 1960's, struggled virtually alone for 

several years to alert State and Federal agencies, as well as 

the public, to that hazard. The State of Tennessee recognized the earthquake threat in 1977, when it formed the 

Center for Earthquake Research and Information (CERI) as 

both a State agency and an independent research unit of 

Memphis State University. The State has con+inued its 

strong support for CERI to the present time and provided 

resources for major programmatic expansions in 1984 and 

1986. The State of Kentucky is one of only a few States in 

the Nation that provide funding for a State seismic network. Kentucky also adopted building code provisions for 

seismic loading in 1981 and upgraded them in 1988. The 

State of Missouri recently established an earthqualre-hazard 

Introduction 3 
~ 

Central Virginia 

seismic zone 

Giles County, Va., 

seismic zone 

seismic zone 

N = 817 

(!) 

I 

200 MILES 

I 

200 KILOMETERS 

MAGNITUDE 

C) 8 

C) 7 

C) 6 

(9 5 

(!) 4 

e 3 

Figure 1. Seismicity of the Central and Eastern United States and adjacent parts of Canada showing earthquakes of 

magnitude 3 or greater from 1568 to 1987. (Figure prepared by G.A. Bollinger, Virginia Polytechnic Institute end State 

University, Blacksburg, Va.) 

mitigation center at Southeast Missouri State University as 

a cooperatively funded effort between the State Emergency 

Management Agency and the university. In conjunction 

with the agency. the center is taking the lead in implementing an earthquake mitigation and preparedness plan for the 

State of Missouri. On November 7, 1989, the first meeting 

of the Illinois "Governor's Earthquake Preparedness Task 

Force" was held to examine the State's preparedness for a 

major earthquake. The goals of the task force are to 

determine the vulnerability of the State to earthquake 

hazards and to recommend ways to reduce the impact of 

those hazards. Three public hearings have been held to 

establish research and development needs. Illinois was 

instrumental in the development of a computer system for 

managing the emergency resources of States in the zone. 

Arkansas has required earthquake preparedness education in 

the 24 counties most vulnerable to an earthquake in the New 

Madrid seismic zone. 

Congress' request for the New Madrid study plan and 

the scheduling of the workshop occurred before the Lorna 

Prieta earthquake struck the San Francisco Bay area on 

October 17, 1989. Clearly. the physical and societal 

impacts of that earthquake dramatically increased the public's awareness of the New Madrid earthquake danger. The 

effects of the Lorna Prieta earthquake also emphasized some 

very important lessons that must be considerr.d in planning future studies of the New Madrid seismic zone: 

• The most severe damage in the bay area was 

concentrated in areas of filled land or unconsolidated sediment; some of these areas als'J sustained 

heavy damage in the 1906 San Francisco earthquake 

(areas of engineered fill suffered littlr. damage). 

Geologic mapping had identified these areas in the 

bay area and could be used to identify such areas 

elsewhere. Many cities, towns, and majcr industrial 

facilities in the New Madrid region tha+ would be 

affected by strong ground motion from a major 

earthquake are located on unconsolidated sediment. 

Specialized mapping could identify the most vulnerable areas, and land-use policies and ~ngineering 

practices could be developed to reduce losses. 

4 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
• High-rise buildings in San Francisco (most of which 

are located on very firm soil or rock foundation) 

were not damaged significantly by the earthquake; 

however, because the ground motion in San Francisco on sites underlain by rock or stiff soil was only 

about 10 percent of gravity and the duration of 

strong shaking was only about 10 seconds-generally below the level that the buildings were designed 

to withstand-the Lorna Prieta earthquake did not 

provide an extreme test of their design. Schools, 

hospitals, and other critical facilities suffered little 

damage. In contrast, numerous structures built on 

filled land experienced ground motion of about 25 to 

30 percent of gravity and sustained heavy damage. 

Earthquake-resistant design and construction practices apparently were effective. Many cities in the 

New Madrid region have not implemented 

earthquake-resistant design practices, and most old 

and new buildings in the region were not designed to 

withstand earthquakes. 

• Government agencies and the general public in 

northern California responded well to the effects of 

the Lorna Prieta earthquake. Preparedness plans and 

exercises had helped lay the groundwork. Until 

recently, little effort had been made to prepare for 

earthquakes in cities in the Central United States, 

and the public is largely complacent about the 

earthquake danger. Regional and local centers-for 

example, the Central U.S. Earthquake Consortium 

(CUSEC), CERI of Memphis State University, 

Saint Louis University, the Governor's Earthquake 

Hazards and Safety Technical and Advisory Panel 

of Kentucky, and the Center for Earthquake Studies 

at Southeast Missouri State University in Cape 

Girardeau-have developed a good knowledge base 

for preparedness measures, but the scope of implementation is limited by the meager resources available. The National Center for Earthquake Engineering Research has implemented an active program 

addressing preparedness and mitigation issues in the 

Eastern United States in which the New Madrid 

region has a prominent role. 

• The location of the Lorna Prieta earthquake had 

been forecast accurately (U.S. Geological Survey, 

1988). It occurred on a section of the San Andreas 

fault system in the Santa Cruz Mountains that was 

identified as the fault segment most likely to produce a strong earthquake in the bay area. This 

successful forecast shows that understanding of the 

mechanics of the San Andreas fault zone has 

improved to the point that mitigation actions can be 

directed to the most hazardous parts of a fault 

system. In contrast, the little that is known about the 

relative probabilities of earthquakes occurring along 

the numerous major fault zones of the New Madrid 

region emphasizes the need for additional concentrated studies. 

The appropriate level of support for New Madrid 

studies in relation to studies of other U.S. seismic zones, as 

well as the balance of effort among the various NEHRP 

Federal agencies, can be determined only through evaluation of the whole NEHRP, a task that is beyond the scope of 

this report. Also, funding for NEHRP agencies to carry out 

the recommendations in this plan is, of course, subject to 

established budget procedures. This plan is intended primarily to provide a basis for budget proposals from each 

NEHRP agency. It can also be used by other organizations, 

such as State geological surveys and emergency agencies, 

to prepare related budget initiatives. Nevertheless, it is 

necessary to base this plan on an approximate level of 

funding to indicate the types of products that are needed and 

the types of projects that are foreseen in the study. The work 

described here could be carried out with total funding 

among all four NEHRP agencies of $5 to $10 million 

annually for 5 years. The exact amount would control the 

pace of the study and the choice of options. After 5 years, 

progress should be reviewed and the plan modified. 

In recent years, New Madrid research studies have 

been funded at under $1 million per year. In fiscal year (FY) 

1990, $3 million was allocated for New Madrid studies 

from funds appropriated to the USGS in Public Law 

101-130 (FY 1990 Dire Emergency Supplemental to Meet 

the Needs of Natural Disasters of National Significance). 

This funding will permit some of the studies described in 

this plan to be initiated; however, most types of research 

require several years to complete, and some, such as 

seismic network operation, are of an ongoing nature and 

require a stable budget. Thus, the FY 1990 funds will be 

used mainly for capital expenditures (equipment and data 

acquisition) and short-term studies that meet urgent needs. 

THE DANGER: SEISMIC RISK ASSESSMENT 

Introduction 

The earthquake dangers in California and Alaska are 

well known to most Americans. Small but sharply felt 

earthquakes occur frequently in those States, and destructive shocks are common enough to maintain public awareness. The relative infrequency of destructive earthquakes 

east of the Rocky Mountains leads to a perception that the 

earthquake danger there is insignificant in comparison with 

the dangers from other natural hazards, such as tornadoes 

and hurricanes. But the low frequency of occurrence of 

eastern earthquakes is offset by the vast area that they affect 

(fig. 2). A recurrence of the great New Madrid earthquakes 

of 1811-12 would be felt from Denver to New York City, 

topple chimneys in Chicago, Knoxville, Dallas, and Kansas 

The Danger: Seismic Risk Assessment 5 
a-

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SAN FERNANDO, 1971 

OUTER RING ENCLOSES INTENSITIES OF VI- VII, AND THE PATIERNED 

AREA REPRESENTS INTENSITIES OF VII AND GREATER 

, 

, ~ 

• 

~~~~;," 

• 

· 

•" 

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CHARLESTON, 1886 

, -'~u I \ f (),' .. 

fill(. -t "lit£ 11.\j t 

-

DAMAGE AREA CORRESPONDS TO INTENSITY VII AND GREATER 

Figure 2. Areas of intensity VI and VII for two great earthquakes of about magnitude 8-New Madrid, Mo., in 1811 and San Francisco, Calif., in 1906-and two 

major damaging earthquakes-Charleston, S.C., in 1886 and San Fernando, Calif., in 1971 (Rankin, 1977). At intensity VI, minor damage occurs; at intensity VII, 

principally architectural damage occurs. Areas affected in the East are much larger than those affected in the West owing to lower seismic-wave attenuation in 

the East. 
ILLINOIS 

ARKANSAS 

\ 

: Little Rock 

I 

I 

~\ 

I '------, 

\ I 

\_ __ ___: 

Figure 3. Regional distribution of estimated Modified 

Mercalli intensities that would result from a recurrence 

of the 1811-12 earthquake series in the New Madrid 

seismic zone. Intensity VIII and above indicates that 

structural damage might occur in a large number of 

buildings. Intensity VII indicates principally architectural 

damage. Intensity VI indicates widely felt shaking and 

City. cause architectural damage to tall buildings throughout most of the Central United States, and have devastating 

physical and societal impacts on the central Mississippi 

Valley (fig. 3). A magnitude 6 earthquake, which has a 

significant possibility of occurrence in the next several 

VII 

0 

I 

0 

I 

200 MILES 

I 

300 KILOMETERS 

items knocked off shelves. This composite intemity map 

shows a distribution of effects more widespread than 

what would result from a single earthquake of magnitude 8.6, because the distributions of effects were plotted for magnitude 8.6 earthquakes that could occur 

anywhere from the northern end of the seismic zone to 

the southern end. (After Hopper, 1985.) 

decades (table 2), would cause severe damage over several 

counties in several States. 

A recurrence of the 1811-12 New Madrid earthquakes undoubtedly would have devastating effe~ts on the 

region and the Nation, but considerable uncertainty exists 

The Danger: Seismic Risk Asses:~ment 7 
Table 2. Earthquake probability estimates for the New 

Madrid seismic zone 

Recurrence time Probability of recurrence (percent) 

m b 

1 M 5

1 (years) Next 15 years Next 50 years 

2':6.0 

2':6.6 

2':7 .0 

2':6.3 

2':7.6 

2':8.3 

Model 1-Time-dependent modef 

70(± 15) 

254(±60) 

550( ± 125) 

40-63 

5.4-8.7 

0.3-1.0 

86-97 

19-29 

2.7-4.0 

Model II-Time-independent (Poisson) modeP 

2':6.0 2':6.3 70( ± 15) 16-24 45-60 

2':6.6 2':7.6 254(±60) 5-7 15-23 

2':7.0 2':8.3 550(±125) 2-4 7-11 

1 Uses Nuttli's (1983) mb-Ms relationship. 2 Probabilities depend on time elapsed since past earthquakes 

(Johnston and Nava, 1985). The time-dependent model was developed to 

describe the recurrence behavior of individual fault segments along plate 

boundaries. 3 Probabilities do not depend on time elapsed since past earthquakes 

(S.P. Nishenko and G.A. Bollinger, unpublished manuscript. 1990). The 

time-independent, or Poisson, model is a good representation of volumetric processes (that is. the combined behavior of numerous faults). The 

difference in probabilities between the two models indicates the uncertainties in understanding the tectonic regime of the New Madrid seismic zone 

and shows the need for further research. 

about how often. where. and when such events are likely to 

occur and about whether other areas in the Eastern United 

States that have not yet experienced destructive earthquakes 

of that magnitude might experience one in the future. One 

goal of earthquake research is to reduce this uncertainty 

about the locations and frequency of damaging earthquakes 

in the eastern part of the country. Such information, which 

is currently inadequate. is essential for deciding where to 

focus efforts to prepare for and cope with earthquake 

hazards and for allocating resources accordingly for preparedness and mitigation measures. 

Information and knowledge that would enable earthquake-hazards assessment in any area are: 

• Geologic (prehistoric)~ historical, and instrumental records of past seismicity: Where, how often, 

and how regularly have strong earthquakes occurred 

in the past? When will the next one occur? How big 

have they been? How big can they be? 

• Geologic setting: Is the area situated along a boundary between two tectonic plates (like the San 

Andreas fault) or in the middle of an old, quasistable plate (like the New Madrid seismic zone)? 

What is the location, length. depth, distribution, and 

direction of movement on the faults that cause the 

earthquakes? What is their structure? What properties make some faults more susceptible to movement 

than others? 

• Current rates and past history of land (crustal 

and surface) deformation: What is the orientation 

of stresses that cause earthquakes? What is the cause 

of the stress? How fast is stress accumulating, and 

what level does it have to reach before faults slip? 

• Efficiency and nature of seismic-wave propagation: How large an area would be affected by 

destructive earthquake shaking? What a~e the predominant vibration frequencies? 

• Vulnerability of existing structures: How vulnerable are existing structures of various mzterials and 

construction types to a strong earthquak~? 

• Effects of strong ground motion on the land 

surface, buildings, and lifeline systems: What will 

be the duration of shaking? Will the ground diminish or amplify the vibrations? How will the structures and lifeline systems respond? 

• Effects of strong ground motion on ground failure: Where will liquefaction and landslides take 

place? What properties and physical setti"'gs lead to 

ground failure of unconsolidated sediments? 

For the New Madrid region, the data currently aYailable for 

assessing the earthquake danger are deficient in many 

respects. This deficiency can be reduced only through 

further research on the topics described in this report. 

Seismicity 

The history of earthquake activity in the New Madrid 

seismic zone (table 1) is dominated by the earthquake 

sequence that struck the area in the winter of" 1811-12 

(Fuller, 1912; Nuttli. 1973). The sequence began on 

December 16. 1811. with a tremendous earthauake, followed by another large shock 6 hours later. ~11bsequent 

great earthquakes occurred on January 23 and February 7, 

1812. In terms of magnitude, these earthquakes are believed 

to be the largest shocks known to have occurred in a 

so-called stable continental interior; in term<;' of area 

affected, they may be the strongest historical shocks in the 

world (Johnston and Kanter, 1990). In contrast to the 

typical pattern of a single principal shock followed by a 

series of aftershocks, the 1811-12 sequence consisted of 

four very large shocks. each of which was followed by 

aftershocks, many of which were themselves significant 

earthquakes. Six aftershocks had magnitudes of 6 to 7, and 

more than 1. 800 aftershocks large enough to be recorded as 

far away as Louisville, Ky., occurred in the firs" 5 months 

following the December 16, 1811 , event. Aftershocks 

continued until at least 1817. About as many felt earthquakes occurred in the Mississippi Valley in 5 months as 

occurred in southern California in the 40-year p~riod from 

1932 through 1972. The most intense earthquake activity in 

the Eastern United States continues to be in the New Madrid 

seismic zone (fig. 1). 

Other strong earthquakes have occurred in the New 

Madrid region since the 1811-12 sequence (ta'Jle 1). Of 

particular note were a magnitude 6.4 earthqua1-e in 1843 

near Marked Tree, Ark., and a magnitude 6.8 earthquake in 

8 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
1895 near Charleston, Mo. These events occurred at the 

southwestern and northeastern ends, respectively, of the 

area most affected by the 1811-12 sequence; perhaps the 

1811-12 fault movement modified stresses and stimulated 

fault movement in those areas. The 1843 earthquake 

cracked walls. felled chimneys, and broke windows in 

Memphis, Tenn. The 1895 earthquake damaged many 

buildings in Charleston and caused sand to liquefy and erupt 

onto the land surface. At Cairo, Ill., buildings swayed, 

chimneys toppled, and church steeples twisted. 

Damaging earthquakes also have occurred in the 

region surrounding the area of greatest 1811-12 activity, 

including southern Illinois and Indiana, western Kentucky, 

and eastern Missouri. The strongest earthquake in the 

Central United States since 1895 occurred in 1968 in 

south-central Illinois on the margin of the New Madrid 

seismic zone. It had a magnitude of 5 .4 and was felt over all 

or portions of 23 States, from Minnesota to Florida and 

from North Carolina to Kansas. Damage consisted primarily of bricks thrown from chimneys, broken windows, 

toppled television antennas, and cracked or fallen plaster. A 

magnitude 5.2 earthquake in 1980 centered in north-central 

Kentucky was felt over 15 States. Property damage 

exceeded $1 million at Maysville. Ky., where 3 7 commercial structures and 269 residences sustained some damage. 

More recently, in 1987, a magnitude 5.0 earthquake in 

southeastern Illinois was felt in 21 States and southern 

Canada and caused one injury and minor damage in 

southern Illinois and Indiana. 

Information on the underlying cause of New Madrid 

seismicity is derived from earthquake focal mechanisms and 

other stress indicators, which show that the New Madrid 

seismic zone is being compressed in an east-northeast-westsouthwest direction (Zoback and Zoback, 1981). This 

orientation is consistent with the direction of drift of the 

North American plate with respect to the mantle and with 

the direction of stress caused by pressure on the plate as it 

moves away from the mid-Atlantic ridge. Although these 

explanations for the origin of the stresses in the crust of the 

North American plate are plausible, they do not explain 

why earthquakes are concentrated in the New Madrid 

seismic zone. 

Regional Tectonic Setting 

The New Madrid seismic zone, which geologically is 

situated in the upper Mississippi embayment (fig. 4). is an 

area of abundant seismicity that extends generally from near 

Charleston, Mo., on the northeast to Marked Tree, Ark., on 

the southwest (fig. 5). The zone of intense seismicity lies 

within a larger region, including parts of Arkansas, Missouri, Illinois. Indiana, Kentucky, and Tennessee, in which 

earthquakes are more dispersed and less common. Major 

structural and tectonic elements in the New Madrid region 

include the Ozark uplift. the southern part of the Illinois 

basin, the Cottage Grove-Rough Creek-Shawnertown fault 

system, the Ste. Genevieve fault. the Wabash Valley fault 

system, and the Reelfoot rift. 

The most seismically active part of the New Madrid 

seismic zone lies within the Reelfoot rift (fig. 5), a 

northeast-striking graben about 40 mi wide and 200 mi long 

(Hildenbrand, 1985). Limited geologic evidence indicates 

that the graben formed about 500 million years ago and was 

filled with thousands of feet of sandstone, shale, limestone, 

and dolomite. Geophysical surveys, particularly aeromagnetic and seismic-reflection data, show that the top of 

crystalline basement rocks is generally about 1.2 mi deep 

outside the rift but is 2.4 to 4. 2 mi deep along the axis of the 

rift. A very thick section of sedimentary rocks originally 

filled an ancient basin along the rift axis. The basin was 

subsequently uplifted to form the Blytheville arch (Hamilton and McKeown, 1988). The well-defined, northeasttrending zone of earthquake hypocenters between Marked 

Tree and Caruthersville, Mo., coincides with the 

Blytheville arch. Near Caruthersville. the pattern of intense 

seismicity changes to a northwesterly trend, w;.ich coincides with the intersection of the Blytheville arch and the 

northwest-striking Pascola arch (Grohskopf. 1955). The 

areal extent of the Pascola arch cannot be ma'1ped adequately from the available subsurface data, but seismicreflection and sparse drill-hole data show that tl'~ Pascola 

arch also was formerly part of a deep sedimentary basin. 

Like the Blytheville arch, this deep basin is now 2 structural 

high but underwent severe erosion that removed several 

thousand feet of sedimentary rocks. 

Seismic-reflection data show that the boundaries of 

the Reelfoot rift are marked by fault zones several miles 

wide that displace basement rocks by as mud' as 1 mi 

vertically and, in some places, also displace younger rocks 

several tens of feet. A few earthquakes are spatially 

associated with the rift-bounding faults, especially along the 

southeastern margin (fig. 5). The po~bility that the southeastern margin of the rift could produce a strong earthquake 

is of major concern. because such an event could be within 

20 mi of Memphis. 

The dispersed seismicity outside the area of intense 

seismicity in the New Madrid seismic zone has net yet been 

linked definitely to any major fault zones. In so·~theastem 

Missouri, the topographically and structurally highest part 

of the Ozark uplift-the St. Francois Mountains-is encircled by seismicity. This seismicity and geomo':phic evidence suggest that minor uplift may be occurrjng in the 

Ozarks. 

Similarly, a crude spatial correlation between seismicity and the Ste. Genevieve fault raises the pmsibility of 

active deformation on that fault. Reconnaissance studies of 

the geomorphology of stream terraces across the fault, 

however, show no evidence of current deformation. Along 

the Cottage Grove-Rough Creek-Shawneetown fault system, there is no obvious correlation between modem 

The Danger: Seismic Risk Assesfment 9 
0 

I 

0 

I 

30 MILES 

I 

30 KILOMETERS 

St. Louis 0 

I 

I 

···:~.·.·. .. ', .. 

so-

• ~. 't 

• I ILLINOIS BASIN 

\. ·~ .. ' • ......._,_ ".s- G . ........_.. - -s-,,s, /:"-~, • ( ,-s-0 • <II:; v -~ .. · 

\ 13· 

MISSOURI 

OZARK UPLIFT 

.... 

-----. ---_....._..._ 

· . . . . . .· .· :: ... ARKANSAS.· , • 36° • • • .• ·-· . ........ --,; 

. . 

.. • 

ST. FRANCOIS 

MOUNTAINS 

. ·. 

"-6<»,. , : . 

-~ . 

KENTUCK~' . 

TENNESSEE 

Area of 

figure 5 

')---MISSISSIPPI -- ~-- -. ---\ ALABAMA 

Figure 4. Seismicity and major structural features of 

the New Madrid seismic zone. Solid circles are 

epicenters (Saint Louis University). Major fault systems discussed in the text are CGFZ, Cottage Grove 

fault zone; RCFZ, Rough Creek fault zone; SGFZ, 

Ste. Genevieve fault zone; STFZ, Shawneetown 

fault zone; and WVFZ, Wabash Valley fault zone. 

The boundaries of the Reelfoot rift are shown by 

the single-hachured lines (hachures on the downseismicity and the major faults. Along the Wabash Valley 

fault system, a crude spatial association between the fault 

system and modem seismicity may be evidence that some of 

the faults are active. Seismologic data from magnitude 4 to 

5 earthquakes in the area show that the style of faulting is 

predominately strike-slip on northeast- or northwesttrending faults in response to a nearly east-west maximum 

horizontal stress orientation. 

thrown side). The boundary of the Blytheville C''"Ch 

is shown by the double-hachured line. lgne'1us 

plutons inferred from geophysical data are shown 

by a v pattern. The stippled line is the margin of the 

Mississippi embayment. For simplicity, earthquc: kes 

within the area shown in figure 5 are not shown (see 

fig. 5). (Figure prepared by F.A. McKeown, U.S. 

Geological Survey, Golden, Colo.) 

In summary, the tectonic framework in the New 

Madrid region beyond the New Madrid seismic zone is only 

poorly known. Modem seismicity cannot be related to 

specific geologic features except in a general way. Until a 

cause-and-effect relationship is developed, the earthquake 

potential of the entire region cannot be reliably assessed. 

Preparedness and mitigation measures cannot t·:- effected 

fully until such assessments are made. 

10 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
.. 

MISSOURI 

.. ' 

ARKANSAS 

BLYTHEVILLE ARCH 

0 

0 

Memphis 

,_J 

't_!S~!+JJ'!}CKY_ 

k r-

.. =..", . ~ ~Reelfoot ·:~ Lake -~· 

TENNESSEE 

25 MILES 

25 KILOMETERS 

35: L-----___:"'-------.......1...-----...J....------------------

Figure 5. Seismicity (from Central Mississippi Valley Earthquake Bulletin of St. Louis University) and 

major geologic structures in the most active part 

of the New Madrid seismic zone. The boundaries 

of the Reelfoot rift are shown by the singlehachured lines (hachures on the downthrown 

side). The boundary of the Blytheville arch is 

Earthquake Effects 

The New Madrid earthquakes of 1811-12 severely 

damaged structures and disrupted the land surface (Fuller, 

shown by the double-hachured line. Igneous plutons inferred from geophysical data are shown bv 

a v pattern. Note the coincidence between t~e 

Blytheville arch and the linear trend in seismicity 

that extends from Marked Tree to Caruthersville. 

(Figure prepared by F.A. McKeown, U.S. Geological Survey, Golden, Colo.) 

1912). The area of greatest disruption encompassed approximately 50,000 mi2

• Within this area, uplift and s1.1bsidence 

on the order of a few feet occurred over hundreds of square 

The Danger: Seismic Risk Assessment 11 
miles; the most notable area of subsidence was at Reelfoot 

Lake in northwestern Tennessee. Several islands in the 

Mississippi River completely disappeared because of flowage of liquefied sediments. Along the bluffs on the eastern 

side of the valley, landslides were commonplace from near 

Cairo, Ill., to south of Memphis (fig. 6). Throughout the 

region, fissures formed at the ground surface, river banks 

caved hundreds of miles from the epicentral area, and huge 

quantities of sand and water erupted onto the surface (fig. 

7). The eruption of sand and water, which resulted from 

liquefaction of subsurface sand layers, flooded approximately 4,000 mi2 with as much as 3 ft of sand and water. 

More than 250 mi2 of timber were destroyed by flooding, 

violent ground shaking, or landsliding. Eyewitness 

accounts describe the entire land surface as being disrupted 

and, in many places, uninhabitable. 

Accounts of the shaking caused by the 1811-12 

earthquakes (Fuller, 1912; Penick, 1981) describe almost 

unbelievable ground motion. Godfrey Le Sieur, a young 

boy and resident of Little Prairie (near Caruthersville, Mo.) 

at the time of the earthquakes, later wrote, 

The earth was observed to roll in waves a few 

feet high with visible depressions between. By 

and by these swells burst throwing up large 

volumes of water, sand, and coal. 

James Audubon, the famous naturalist, experienced one of 

the shocks while riding in Kentucky: 

The ground rose and fell in successive furrows 

like the ruffled waters of a lake. The earth waved 

like a field of corn before the breeze. 

L. Bringier, who lived with Indians near New Madrid and 

was later a surveyor in New Orleans, wrote that the water 

forced its way through the surface deposits, 

... blowing up the earth with loud explosions. It 

rushed out in all quarters, bringing with it an 

enormous quantity of carbonized wood, 

reduced mostly into dust, which was ejected to 

the height of from 10 to 15 feet, and fell in a 

black shower, mixed with the sand, which its 

rapid motion forced along; at the same time the 

roaring and whistling produced by the impetuosity of the air escaping from its confinement 

seemed to increase the horrible disorder .... In 

the meantime the surface was sinking and a 

black liquid was rising to the belly of my horse. 

The few structures that were present in the area were 

heavily damaged. Masonry and stone structures were damaged as much as 150 mi away. Chimneys were destroyed in 

Louisville, Ky., about 250 mi away, and less extensive 

chimney damage was reported at distances of over 400 mi. 

The earthquakes were felt southward to the Gulf Coast, 

southeastward to the Atlantic shore, and northeastward at 

least to Quebec. No reliable reports to the west are 

documented. 

If estimated isoseismal areas to the west a·e included, 

the earthquakes of December 16, 1811, and February 7, 

1812, had the greatest potential damage and thr. largest felt 

areas known in the earthquake history of the United States 

and possibly of the world (Johnston and Kanter, 1990) (fig. 

2). The area of potential damage (the area shaken at 

intensity VII or greater) was about 250,000 mi2

• For 

comparison, a reasonable extrapolation of the area of 

intensity VII or greater for the 1964 Alaska earthquake 

covers an area of about 80,000 to 100,000 mi2 . The 1906 

San Francisco earthquake affected an area of only about 

12,000 mi2 at intensity VII (or 24,000 mi2 , if isoseismal 

symmetry to the west in the Pacific Ocean is assumed). 

Thus, the area of strong shaking associatei with the 

1811-12 earthquakes is two to three times larg~r than that 

associated with the 1964 Alaska earthquake and 10 times 

larger than that associated with the 1906 San Francisco 

earthquake. 

Potential Losses 

Preliminary estimates of potential earthquake losses 

for dwellings in the Central United States are very large. 

Analysis of the intensity patterns of the 1811-12 earthquakes and other earthquakes in the Central United States in 

conjunction with the present-day distribution cf dwellings 

gives an upper-bound loss estimate of about $:0 billion to 

dwellings (in 1980 dollars) for a recurrence of the 1811-12 

sequence (Algermissen, 1990). The expected maximum 

loss to dwellings in a 50-year period (at a 10-percent chance 

of being exceeded) is about $5.6 billion (1980 c.ollars), and 

a magnitude 6 to 7 earthquake would cause ap:'Jroximately 

$3.6 billion in dwelling losses (S.T. Algermissen, unpublished data, 1990; 1990). 

The central Mississippi Valley is a majo~ communication and transportation corridor. Communication facilities, such as radio and microwave towers and telephone 

trunk lines, are vulnerable. Barge traffic on the river, 

natural gas and crude oil pipelines, interstate highways, and 

power lines all provide essential services, the loss of which 

would have a heavy impact on the entire Central and 

Eastern United States These transportation and lifeline 

facilities are highly vulnerable to earthquake damage, 

particularly because their structural integrity depends, to a 

great extent, on the stability of the ground. De~truction of 

pipelines would severely disrupt the delivery of ~nergy fuels 

to the northern and northeastern parts of the Urited States. 

The Mississippi River would be strongly affected by 

a large earthquake. After the February 7, 1812, earthquake, 

two waterfalls or heavy rapids formed in the rive· and halted 

traffic for several days. Extensive changes in tte course of 

the river channel made navigation difficult and hazardous. 

Eliza Bryan, a resident of New Madrid, de:"cribed the 

effects of the 1811-12 earthquakes on the river (Fuller, 

1912): 

12 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
Figure 6. Trees tilted by a landslide along the Chickasaw Bluffs near Reelfoot Lake in northeastern Tennessee, 

photographed in 1904 (Fuller, 1912). The landslide was triggered by the New Madrid earthquakes of 1811-12. 

The Danger: Seismic Risk Assessment 13 
MISSOURI 

----~~ 

ARKANSAS 5 

- of aerial j photograph 

I " l ______ _ 

TENNESSEE 

20MILES I I I I 

I I I I I 

25 KILOMETERS 

0 1 MILE. 

~--------~------~ 

0 

Figure 7. Aerial photograph taken in 1959 near Portageville, Mo. (Obermeier, 1989). White spots and white 

lineations are from liquefied sand that was vented to the 

surface over dark clay during the 1811-12 earthquakes. 

1 KILOMETER 

The lineations are caused by ground cracks that are due to 

lateral spreading; their pattern is controlled by parameters 

such as the thickness of the clay cap over the liquefied 

sand and the locations of ancient stream channels. 

14 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
At first the Mississippi seemed to recede from its 

banks, its waters gathered up like mountains, 

leaving boats high upon the sands. The waters 

then moved inward with a front wall15 to 20 feet 

perpendicular and tore boats from their moorings and carried them up a creek closely packed 

for a quarter of a mile. The river fell as rapidly as 

it had risen and receded within its banks with 

such violence that it took with it a grove of 

cottonwood trees. A great many fish were left 

upon the banks. The river was literally covered 

with wrecks of boats. 

Caving of steep banks along rivers and streams was 

the most widespread type of landsliding triggered by the 

1811-12 earthquakes. According to witnesses (Penick, 

1981), 

In many places, the banks of the river ... sunk 

hundreds of acres together, leaving the tops of 

the trees to be seen above the water. 

[Banks] fell in "large columns"; in some places 

"five, ten, and fifteen acres ... sunk down in a 

body .... " 

In a future large earthquake, barge traffic would 

almost certainly be interrupted, perhaps for weeks, if 

substantial dredging were needed to clear river channels. 

Foundations of structures and levees could fail in numerous 

places. Facilities along the river bank, particularly large 

grain silos and fuel and fertilizer tanks, could collapse and 

cause fires and spills that would pollute the river. Damage 

to landfills, wastewater-treatment facilities, pipelines, and 

chemical storage facilities could cause widespread contamination of ground water and disruption of water-supply 

systems. 

Damage to the interstate and other highway systems 

would be extensive in a repetition of a great earthquake. 

The various forms of ground failure (liquefaction, landslides, and so on) would weaken or destroy highway 

foundations. Ground failure combined with strong ground 

shaking would severely impact bridges and overpasses, 

which generally have not been designed with earthquakes in 

mind. The bridges across the Mississippi River and its 

numerous tributaries are located on ground that is most 

susceptible to failure and amplified shaking. 

The central Mississippi Valley is one of the most 

productive agricultural areas in the United States. Not only 

would farming be disrupted by general earthquake damage, 

but the extensive canal system that drains water from 

lowlands also could be damaged both by liquefaction and 

landslides and by uplift and subsidence of the land surface 

associated with a great earthquake. Large areas could be 

inundated by several feet of water, and fields could be 

covered by liquefied sand vented to the ground surface. 

Electric power failures could also affect pumping and other 

equipment systems. 

An earthquake in the magnitude 6 to 7 range, such as 

the one that occurred near Charleston, Mo., in 1895, would 

also cause severe shaking, but the area affected would be 

smaller than the area that would be affected by repr.tition of 

one of the great shocks of the 1811-12 series. Hurdreds of 

square miles near the epicenter would experience ground 

motions strong enough to jeopardize many buildings and 

other facilities; within an additional tens of thou~::t.nds of 

square miles, shaking would be strong enough to cause 

damage to structures located on unfavorable geologic foundation material. An example of the effect of a modem 

earthquake of similar magnitude in a different geologic 

setting is provided by the San Fernando, Calif., ea'thquake 

of 1971 (magnitude 6.6) (intensity pattern in fig. 2). That 

shock killed 58 people, caused a near-catastrophic dam 

failure and collapses of freeway overpasses, and produced 

$500 million (1971 dollars) in damages. We have not had a 

modem magnitude 6. 8 earthquake in a region similar to the 

New Madrid seismic zone. The 1895 shock occurrr.d before 

construction of the numerous facilities that are nov' present 

in the area. 

A magnitude 6 earthquake beneath a met~opolitan 

center would cause substantial damage. Recent examples of 

such a shock outside of the New Madrid seismic zone are 

the Whittier Narrows, Calif., earthquake of 1987 (magnitude 5. 7), which killed 8 people and caused propetty losses 

of over $300 million (1987 dollars), and the magnitude 5.5 

Newcastle, Australia, earthquake of December 27, 1989, 

which killed 12 people and caused $1 billion in property 

losses. Unreinforced masonry buildings, of which there are 

many in the metropolitan areas of the New Madrid seismic 

zone, were particularly hard hit in the Whittier Narrows 

shock. The region of intense shaking in a magnitude 6 

earthquake is, however, small enough that there are areas of 

the New Madrid seismic zone in which such an errthquake 

could occur without strong shaking extending to heavily 

populated areas. 

THE RESPONSE: PREPAREDNESS AN[' 

MITIGATION 

Although the greatest devastation in the New Madrid 

region would be caused by the recurrence of a ma~nitude 8 

earthquake, such an event may happen very rarely, perhaps 

only once in a thousand years or more, on the average. 

However, extrapolation of earthquake statistics (for example, Johnston and Nava, 1985) indicates that, in that same 

thousand-year period, roughly 5 (±2) earthquakes in the 

magnitude 7 to 8 range and about 14 ( ± 6) earthquakes in 

the magnitude 6 to 7 range would occur. Thus, th~ type of 

earthquake on which planning should be based may be one 

in the magnitude 6 to 7 range. Only time will tell how valid 

such extrapolations are for the New Madrid seismic zone. 

The Response: Preparedness and Mitiga•;on 15 
LOSS REDUCTION MEASURES 

Figure 8. Goals of community actions in implementing loss reduction measures. (Figure preparec by 

W.W. Hays, U.S. Geological Survey, Reston, Va.) 

Nevertheless, the best available evidence is sufficient to 

justify a concerted and aggressive mitigation and preparedness effort. By identifying and quantifying earthquake 

hazards and by adopting and implementing preparedness 

and mitigation measures, a community can build the capacity to withstand the physical effects of an earthquake (fig. 

8). Experience in California convincingly demonstrates that 

earthquake preparedness and mitigation measures are effective in saving lives and reducing losses. 

Preparedness activities must be initiated long before 

an earthquake to prepare emergency managers for the 

response and recovery periods. Such activities encompass 

the following: 

• Establishing a process to develop emergency 

response and recovery plans that are based on the 

best available earth-science and engineering data. 

• Utilizing information gained from scientific and 

engineering studies and from hazard and risk assessments. 

• Developing effective programs to disseminate information and educate the public on the potential 

vulnerability of the community in such a way as to 

stimulate real action and accomplish actual changes 

in structural and nonstructural mitigation as well as 

actual public preparedness on both an individual and 

a community basis. 

Mitigation activities, like preparedness activities, 

also are carried out before the event, their goal being the 

reduction or prevention of damage and societal disruption. 

They include the following: 

• Developing realistic estimates of pot~ntial losses 

and societal impacts for one or more possible 

events. 

• Reducing vulnerability in the community. 

• Utilizing seismic zonation; that is, identifying the 

spatial distribution and nature of specific types of 

hazards and enacting land-use restrictions in hazardous areas. 

• Adopting and implementing codes and Handards for 

the siting, design, and construction of nr.w buildings 

and lifelines (for example, energy, water, transportation, and communication systems). 

• Adopting and implementing criteria fo':" the siting, 

design, and construction of essential and critical 

facilities (for example, schools, hosp:tals, emergency command centers, and conve"'tional and 

nuclear powerplants) that are vital to th~ life of the 

community and must remain functioral after an 

event. 

Earth scientists, engineers, and social scientists build 

the knowledge base that practitioners use in preparedness 

and mitigation activities. Earth scientists and engineers 

evaluate the physical nature of the earthquake hazards of 

ground shaking, earthquake-induced ground failure, 

surface-fault rupture, regional tectonic deformation, flooding from dam failure, fire following an earthquake, and the 

aftershock sequence. Their goal is to understand the phys16 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
ical system for each type of earthquake effect, the· parameters that control the cause-and-effect relationships of the 

physical system, the central tendency and variability in 

space and time of each parameter, and the sensitivity to 

extrapolation of parameters beyond the limits of the data. 

Social scientists study the social components of 

earthquake hazards. They analyze societal systems and 

focus their research on the behavior of individuals, households, organizations, and communities. Within this framework of individual and organizational behavior, social 

scientists analyze how people and institutions respond to, 

prepare for, and mitigate earthquake and related hazards. 

Social scientists are, for example, interested in how perception of risk is communicated to vulnerable communities. In 

addition, some social scientists concentrate on questions of 

policy development or policy analysis. For example, they 

might analyze how technical and nontechnical information 

is transferred from researchers to practitioners or how 

social, political. and (or) cultural factors constrain or 

promote the utilization of hazard-reduction information. 

Experience has shown that knowledge alone makes 

no contribution to earthquake preparedness and mitigation 

measures if the knowledge base is unknown, misunderstood, inappropriate, unintelligible, misdirected, or 

ignored. Consequently, a vigorous awareness and education 

program would be needed to support earthquake-hazard 

mitigation and preparedness activities in the New Madrid 

region. 

THE PLAN: PREPARING FOR THE NEXT 

NEW MADRID EARTHQUAKE 

Introduction 

Knowledge of the New Madrid seismic zone lags 

behind that of most seismic zones in the Western United 

States, particularly the San Andreas fault zone, for several 

reasons: 

• The seismically active faults in the main part of the 

New Madrid seismic zone are concealed by as much 

as 3,000 ft of poorly consolidated sedimentary 

rocks, whereas most of the San Andreas fault zone 

is exposed at the surface. 

• Earthquakes occur more frequently in California. 

This frequency thereby yields more data that are 

critical to understanding their cause, poses a greater 

danger, and attracts greater scientific and political 

attention. Consequently, resources devoted to earthquake research are considerably greater in the West 

than they are in the East. 

• The San Andreas fault zone is the boundary between 

the Pacific and North American plates, a relatively 

well understood tectonic regime. In contrast, the 

tectonic framework for .. intraplate" earthquakes in 

the New Madrid region (and worldwide) is poorly 

understood. 

Thus, much research is needed in the New Madrid seismic 

zone to achieve a level of knowledge comparable to that 

achieved in California. 

Although much remains to be done, significant 

progress in understanding the New Madrid seismic zone has 

already been achieved. As recently as the early 1970's, 

before the formation of NEHRP, the pattern of ea'ihquake 

epicenters in the region was poorly resolved; it looked like 

a buckshot pattern from a shotgun blast. No geologic 

explanation accounted for New Madrid seismicity. Following the installation of the seismic network, the dispersed 

epicenter pattern was resolved into several well-defined, 

linear trends that correspond to the locations of buried fault 

zones, and most of the earthquakes can now be attributed to 

the reactivation of faults in the Reelfoot rift. Many of the 

faults in the rift have been identified on seismic-reflection 

profiles, and the amount of vertical movement has been 

measured on some of them. Exploratory trenches have been 

dug in several places where faults extend close to the 

ground surface and, in one place, have yielded esf'llates of 

the rates of fault movement. 

Some of the most important questions that cannot yet 

be satisfactorily answered are: 

• How can New Madrid seismicity be exp~::tined in 

terms of global tectonic processes? 

• What are the rates and modes of crustal deformation? 

• Do the main seismogenic structures extend northeastward into southern Illinois and Indiara, or are 

the earthquakes in these areas caused by movement 

on structures unrelated to the Reelfoot rift? 

• How far does the New Madrid seismic zone extend 

southwest into central Arkansas? 

• How frequently do great (magnitude 8) anrl smaller 

destructive earthquakes occur? Is their o~currence 

periodic, quasi-periodic, or episodic? Ove~ the long 

term (centuries or millennia), does seismicity 

migrate to other intraplate areas? 

• On which fault segments of the New Madr~d seismic 

zone and surrounding areas are the next d ~structive 

earthquakes likely to occur? 

• What will be the effects of future earthquakes on the 

poorly consolidated ground in the Mississippi Valley? 

• What is the potential for amplification of t"-e ground 

motion and for ground failure? 

The answers to these questions not only will improve 

the basis for mitigating earthquake hazards in the New 

Madrid region but also will provide a better understanding 

of earthquakes elsewhere in the Central and Eastc'n United 

States. Moreover, results from the New Madrirl seismic 

zone will improve the general understanding of intraplate 

The Plan: Preparing for the Next New Madrid Earthq1·•ake 17 
earthquakes and thereby help to reduce casualties and 

damage from earthquakes in similar environments worldwide. 

Purpose 

The overall purpose of an intensified study of the 

New Madrid seismic zone, which is consistent with the 

general mission of NEHRP, is to reduce casualties and 

damage from earthquakes through improved estimates 

of seismic risk and implementation of earthquakehazard preparedness and mitigation measures. 

Goals 

Five goals have been identified for an intensified 

study of the New Madrid seismic zone: 

1. Implementing earthquake-hazard mitigation 

measures. 

2. Improving preparedness for earthquakes of 

magnitude 6 or larger. 

3. Establishing a modern seismic network in the 

New Madrid seismic zone to monitor the sizes, 

locations, and characteristics of the earthquakes and to determine the nature of the 

ground motions that they generate. 

4. Locating faults that could cause destructive 

earthquakes, determining the recurrence rates 

of earthquakes, and delineating areas of potential damage. 

5. Improving seismic-risk assessments. 

Activities 

The activities that have been identified to achieve the 

goals of an intensified study of the New Madrid seismic 

zone are listed below. Activities associated with implementation of mitigation and preparedness and those associated 

with research should proceed concurrently. Each incremental improvement in implementing earthquake-hazard mitigation and preparedness measures would have a corresponding benefit in terms of loss reduction. 

In this discussion of activities, some goals have been 

subdivided into objectives to show more clearly how certain 

activities relate to different aspects of a goal. 

Goal1: Implementing earthquake-hazard mitigation 

measures 

ACTIVITIES 

a. Facilitate adoption of structural design codes that 

include appropriate provisions for soil effects and 

earthquake resistance and of land-use policies that 

take into account earthquake hazards. 

b. Develop effective and economical to.chniques to 

facilitate repairing, strengthening, and retrofitting 

unreinforced masonry and other vulnerable buildings and structures. 

c. Increase education and communicatio'l concerning 

earthquake risk and earthquake-hazards preparedness and mitigation measures. 

Discussion of Goal 1 

Four major research needs have been identified to 

implement earthquake-hazard mitigation mea"ures in the 

Central United States (Hanson, 1986): (1) assess the capability of existing buildings to withstand earthquakes, (2) 

verify the techniques for repairing, strengt'Iening, and 

retrofitting structures, (3) implement remedial measures, 

and (4) develop construction methods for enh2ncing earthquake resistance. Each need requires reevaluation of existing methods and development of new procedures drawing 

on experience in regions of high seismicity. Because 

resources for strengthening and repairing existing structures 

and for constructing new buildings are limited, earthquake 

mitigation practices in regions of moderate seismicity may 

vary from those developed for regions of high seismicity. 

To meet these needs, research and development work 

is required in three general areas: (1) behavior of structures 

in response to earthquake shaking, (2) nondest~uctive testing of structures, and (3) building codes. Subs .. antial work 

needs to be done in evaluating the earthquake response of 

structures that may have little earthquake re"istance. A 

feasible, cost-effective solution for these structures in the 

New Madrid seismic zone entails more than simply modifying building codes that have been calibrated frimarily for 

highly seismic regions. New procedures for nondestructive 

testing and new design and evaluation rrethods are 

required, and they must be communicated to a professional 

community that has not dealt extensively with earthquake 

risk. For the Central United States, assessment of the 

earthquake hazard is a very critical issue. An overly 

conservative estimate of the hazard could result in an 

overestimation of the cost of solving the problem, which in 

tum could result in nothing being done to reduce the risk. 

Goal 2: Improving preparedness for earthquakes of 

magnitude 6 or larger 

ACTIVITIES 

a. Identify, assess, and retrofit, if neces"ary, those 

structures and facilities having special importance 

to survival and recovery in the event of an earthquake. 

b. Prepare loss estimates for large cities. 

c. Prepare earthquake response and recovery plans. 

d. Provide training tailored to the needs of those who 

respond to emergencies. 

18 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
Discussion of Goal 2 

Although earthquake preparedness in the New 

Madrid seismic zone lags behind that in some of the western 

earthquake zones, some important progress has been made. 

The Central U.S. Earthquake Preparedness Project 

(CUSEPP) was initiated by FEMA in 1982. CUSEPP's 

short-term goals were to (1) prepare maps showing the 

intensity of effects for selected earthquakes in the New 

Madrid seismic zone, (2) inventory structures, lifelines, and 

critical facilities in selected cities in the Central United 

States, and (3) assess the risk in those cities. Little Rock, 

Ark., Carbondale, Ill., Evansville, Ind., Paducah, Ky., 

Poplar Bluff, Mo., and Memphis, Tenn., were selected for 

these assessments (Federal Emergency Management 

Agency, 1985). The long-term goals ofthe project are to (1) 

increase the awareness of public officials and the private 

sector of earthquake hazards, (2) develop options for 

engineering solutions based on the balance of risk and cost, 

(3) accelerate the implementation of earthquake-hazard 

mitigation and preparedness strategies, and ( 4) improve 

earthquake response plans. 

To facilitate its earthquake preparedness efforts, 

FEMA formed the Central U.S. Earthquake Consortium 

(CUSEC) in 1983. CUSEC consists of representatives of 

the seven States that are most vulnerable to damage from 

earthquakes in the New Madrid seismic zone: Arkansas, 

Illinois, Indiana, Kentucky, Mississippi, Missouri, and 

Tennessee. The goal of CUSEC is to ensure a coordinated 

program for achieving earthquake preparedness and mitigation goals common to all seven States. CUSEC developed 

and encouraged the adoption of a multistate-interstate compact, which allows neighboring States to share resources 

during an earthquake emergency in fields such as medicine, 

engineering, law enforcement, and fire fighting. The compact addressed liability protection for emergency personnel 

who render services in States where they are not licensed, 

registered, certified, or insured. 

Goal 3: Establishing a modern seismic network in the 

New Madrid seismic zone to monitor the sizes, 

locations, and characteristics of earthquakes and to 

determine the nature of the ground motions that they 

generate 

Objective 3.1: Install and maintain a modern seismic network to 

monitor earthquakes in the New Madrid seismic zone 

ACTIVITIES 

a. Upgrade the present regional seismic network (fig. 

9) with modem three-component, broadband, 

high-dynamic-range instruments. The network 

would cover approximately the area of intensity 

VII shaking shown in figure 2. 

I 

MISSOURI 

D 

D 

ARKANSAS 

100 MILES 

100 KILOMETERS 

Figure 9. Current regional seismic network in t'1e New 

Madrid seismic zone. Symbols denote network operators: 

triangles, Saint Louis University; circles, University of 

Kentucky; squares, Center for Earthquake Resecrch and 

Information/Memphis State University; and stars, Tennessee Valley Authority. Solid symbols are three-conponent 

stations; open symbols are vertical component only. 

Strong-ground-motion instruments (fig. 11) are not 

shown. (Figure prepared by A.C. johnston, Center for 

Earthquake Research and Information/Memphis State University, Memphis, Tenn.) 

b. Integrate the regional earthquake monitoring network with the U.S. National Seismic Network 

(fig. 10) and establish a common data transmission system. 

c. Upgrade and extend the spatial extent of the 

seismic coverage on the periphery of the New 

Madrid seismic zone. 

Objective 3.2: Obtain records of strong ground motion and data 

on seismic-wave attenuation 

ACTIVITIES 

a. Improve the current regional network of strongground-motion stations (fig. 11). 

b. Establish two field laboratories in areas of intense 

seismicity in the New Madrid seismic zone to 

acquire data on earthquake characteristics near the 

source and seismic-wave propagation, including 

strong ground motion. (Each array would consist 

The Plan: Preparing for the Next New Madrid Earthqu~ke 19 
; 

; 

\ 

' ~--·-·-·-· \ 

·-·-·---------4 WI CONSIN 

) I. -·-.. ~ J '-...,·-·"2S:': l 

\~ \ 

\ 

I IOWA 

I 

\,~ ~­'\ 

' ) 

"' ( 

t ( 

' I ( , 

···-· ·-·-·-·-·-·-·-·-·----, l"'"l 

r 

~0 ~ ~ OHIO 

~------~~------~!---l------~----~--------1 

KANSAS 

MISSOURI 

--MMI.VII 

Figure 10. U.S. National Seismic Network 

(USNSN) stations in the Central United 

States. The area affected by shaking of intensity VII or greater during the 1811-12 New 

Madrid earthquakes is shown by the solid line 

(dashed where there are no data). The area 

covered by the regional seismic network is 

indicated by the dash-dot line. The regional 

stations would be linked to satellite communication nodes of the USNSN by radio or 

of eight three-component high-frequency instruments deployed at the surface, together with one 

array of instruments in a deep drill hole.) 

c. Install a strong-ground-motion instrument array of 

high dynamic range within or near a large metropolitan area (for example, Memphis) to obtain 

records of moderate-sized earthquakes that can be 

) 

\ 

} 

I 

~I 

J ..;' 

) 

"-.....J I 

\ 

.J _, .I 

'\. 

\. 

:>t 

/ / 

---~------

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GEORGIA 

...... \ 

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telephone. Data would be relayed to research 

centers through the USNSN master station in 

Golden, Colo., by means of satellite antennas; this concept is illustrated by antenna 

symbols at Memphis, Tenn., and Saint Louis, 

Mo., where the largest regional network 

operators are located. (Figure prepared by 

R.E. Needham, U.S. Geological Survey, 

Golden, Colo.) 

used to predict the ground motion from a future 

large earthquake. (This installation would consist 

primarily of a vertical array of ground··motion and 

soil-dynamics sensors in a borehole.) 

d. Integrate the maintenance of strcng-groundmotion instruments into the national strongground- motion program. (USGS pers0nnel could 

20 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
35° 

MISSOURI 

D + 

D 

f-.------------, + 

/ 

/ 

/ 

~ I 

I 

/( 

+ 

+ 

D --

I 

I 

) 

+ KENTUCKY 

I 

\ rgJ r-

/' //'\.._( '\ 

' \ I +, v------------------

+ \ + 

-' .... [Q] 

\[Q] , ....... + 

' TENNESSEE ' / + L_ I ________ J / + -

+ 

ARKANSAS ~ 

\ 

- + ( E8 r-J 

/ / 

( 

I 

\ 

/J E8 

/ 'x 

I 

_\ 

)-

/ 

~l------r-___LI--,---,-IL___-,--____LI ____ _J5p MILES 

0

1 I I I I 

50 KILOMETERS 

/ ~----------------------------------------~ 

OPERATOR No. of Stations Symbol 

U.S. Geological Survey 20 + 

U.S. Army Corps of Engineers 4 D 

Department of Energy 6 • 

National Center for Earthquake 

Engineering Research 4 [Q] 

Center for Earthquake Research 

and Information 2 E8 

University of Kentucky 1 r8J 

Tennessee Valley Authority 2 X 

Figure 11. Current strong-ground-motion stations in the New Madrid seismic zone (Figure prepared by K.H. j;}cobs, 

National Center for Earthquake Engineering Research, Lamont-Doherty Geological Observatory, Palisades, N.Y.) 

The Plan: Preparing for the Next New Madrid Earthqu'lke 21 
be stationed in the New Madrid seismic zone to 

implement this recommendation.) 

e. Develop a small, portable seismic network and 

provide for its rapid deployment to monitor aftershocks. (This network would consist of eightthreecomponent seismometers connected to a regional 

seismic-network satellite processor and would be 

used to define site-specific ground-motion characteristics.) 

f. Deploy semiportable seismographs to study 

seismic-wave propagation to larger distances. 

(Selected studies could be conducted at St. Louis 

and Louisville, for example.) 

Objective 3.3: Improve capabilities to process and analyze data 

from earthquake-monitoring systems 

ACTIVITIES 

a. Establish research centers to conduct and monitor 

seismic network and other instrument operations, 

locate earthquakes, and archive waveform and 

other earthquake data for future use. (These data 

centers, which would have separate functional 

responsibilities, would provide basic data to all 

research scientists for earthquake-hazard studies 

and would maintain the earthquake-monitoring 

networks.) 

b. Upgrade USGS capabilities to support earthquake 

monitoring systems and to utilize the data in 

earthquake-hazard assessment projects (National 

Academy of Sciences, 1990). (The USGS projects 

would include support services to link the regional 

seismic network and the USNSN, acquisition of 

data for common use, and interpretation.) 

Discussion of Goal 3 

Although the present seismic network is crucial to 

improving our knowledge of earthquakes in the New 

Madrid region, it now lacks a funding base and has major 

technical limitations that must be corrected to yield further 

advances. The current network was designed 15 to 20 years 

ago, when its goals were only to locate and determine the 

magnitudes of small earthquakes and to obtain a focal 

mechanism for a few larger ones. Today, more information 

must be obtained from the earthquake recordings to answer 

the complex questions related to earthquake hazards. The 

majority of seismometers in the network (fig. 9) do not 

sense the horizontal component of ground shaking, have 

limited frequency response and limited dynamic range, and 

are not installed in boreholes, where sensitivity would 

increase owing to the reduction of surface noise. 

Horizontal-component seismometers would provide 

data to determine earthquake locations more accurately and 

would, for the first time, provide data on the transverse 

waves that are the main cause of earthqu"'ke damage. 

Without better locations, including accurate depth estimates, the geologic structures causing the earthquakes 

cannot be reliably identified. In addition, the~e data would 

be used for research on the shear modulus cf crustal and 

surficial materials, a property that characterizes the mineral 

composition and fluid content of rocks and can be used to 

understand the rupture process of earthquakes. The data 

would also permit studies of material anisotropy (for example, seismic waves traveling at different velocities in 

different directions) that could be used not only to map fault 

zones but also to monitor the stress buildup fo"" future large 

earthquakes. Finally, the horizontal data p-ovide better 

estimates of the attenuation of ground shaking with distance 

and are necessary for accurate determination of earthquake 

focal depths. 

A major deficiency of the current seismic instruments 

is that they record earthquakes of about magnitude 3 and 

smaller on scale, but larger earthquakes caus~~ them to go 

off scale. The current instruments are set this way to sense 

the numerous small earthquakes that are used to delineate 

active faults. The tradeoff, however, sacrifices recording 

the complete waveform for the few larger (magnitude 4+) 

earthquakes. Thus, no usable near-source reccrd of ground 

motion exists for larger earthquakes in the New Madrid 

seismic zone that can be used to define the expected shaking 

in metropolitan areas during major earthquake". This deficiency can be resolved by using modern instruments having 

wide-dynamic-range digital telemetry and recording. 

Several metropolitan areas and many critical facilities 

are located on poorly consolidated sediments in the New 

Madrid seismic zone. The prediction of ground motion at 

the surface is calculated from ground motion incident at the 

base of these sediments. Thus, for reliable estimates of 

ground motion at the surface, it is necessary to install 

seismometers at the base of the poorly consolidated sediments and also at the surface. The thickness of poorly 

consolidated sedimentary rocks in the most densely populated parts of the New Madrid region is as gr~at as that in 

any earthquake zone in the country (as much as 3,000 ft). 

Ground-motion prediction methods developed for California need to be calibrated for' this kind of geologic setting. 

Goal 4: Locating faults that could cause d£~tructive 

earthquakes, determining the recurrence rC'tes of 

earthquakes, and delineating areas of potential 

damage 

Objective 4.1 : Define the boundaries and characteristics of seismic 

source zones in the New Madrid seismic zone and surrounding 

areas 

ACTIVITIES 

a. Expand geologic and geophysical studies; trace 

the areal extent of geophysical features at depth. 

22 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
b. Conduct geologic mapping, including shallow 

drilling to determine the physical properties of 

subsurface materials. 

c. Acquire additional high-resolution and reconnaissance geophysical data (gravity. magnetic, seismic reflection) to fill critical gaps in existing data 

sets. 

d. Identify deep faults that extend to the surface by 

means of seismic-reflection and other geophysical 

data. 

e. Drill one or more research holes to determine the 

physical properties of geologic materials under 

realistic conditions, to calibrate geophysical data, 

and to permit borehole monitoring of seismogenic 

processes. 

Discussion of Objective 4.1 

Accurately defining and characterizing seismic 

source zones require a clear understanding of the relationship between earthquakes and major geologic structures at 

the depths where earthquakes are generated. Subsurface 

geologic and geophysical studies conducted during the past 

15 years in the New Madrid seismic zone have shown a 

strong correlation between seismicity and specific fault 

zones associated with the Reelfoot rift. 

Geologic investigations of earthquakes in the New 

Madrid seismic zone have focused primarily on establishing 

the relationship between seismicity and specific structures 

within the Reelfoot rift. Subsurface geologic and geophysical data have been invaluable in identifying and characterizing the major seismic source zone along the axis of the 

rift. although a comprehensive, regional earthquake-hazard 

assessment must include information on the earthquake 

potential of other major faults both inside the rift and 

outside it, knowledge of which is now completely lacking. 

For example, in the past 100 years, five earthquakes of 

magnitude 4.5 to 5.5 have occurred in the Wabash Valley 

seismic zone of southern Illinois and southwestern Indiana. 

A magnitude 5.0 earthquake in southern Illinois in June 

1987 was felt in 21 States and southern Canada. The 

historical record of the Central United States also shows a 

relatively high level of seismicity along the eastern and 

southeastern margins of the Ozark uplift. Thus, regional 

seismicity shows that the scope of deep structural studies 

should be expanded beyond the bounds of the Reelfoot rift 

to encompass important structural features such as the 

Wabash Valley fault zone, the Cottage Grove-Rough Creek 

fault zone, the Ste. Genevieve fault zone, and the Ozark 

uplift (fig. 3). Studies are needed to establish a geologic and 

geophysical basis for defining seismic source zones 

throughout the region and to determine the potential for 

damaging earthquakes in each zone. 

Expanded regional studies will require that critical 

gaps in existing aeromagnetic and gravity data be filled. 

Aeromagnetic and gravity data acquisition was originally 

designed to identify broad-scale structural features such as 

major tectonic blocks, shallow igneous intrusions, and 

anomalous zones of the crust in the northern Mifsissippi 

embayment. High-resolution aeromagnetic and graYity data 

sets that uniformly cover the rift and the surrounding region 

are now needed. These data are vital to correctly interpret 

the structural relationships of features at seismogeni':' depths 

and to resolve details about the structures in the upper crust 

in the area north of the Reelfoot rift. In addition, selected 

areas within the rift need specialized geophysical investigations. For example, magnetotelluric surveys in the Reelfoot 

rift could provide detailed information about s•Tuctural 

relationships in the middle and lower crust in the rift and 

help determine the physical properties of a low-velocity, 

high-attenuation zone along the center of the rift where 

earthquakes are concentrated. Similarly, detailed a~romagnetic and gravity profiles could refine geophysical models 

and clarify the interrelationships among plutors, deep 

basins, fault zones, rift boundaries, and seismicity concentrations. 

Geologic mapping is a fundamental source of structural and stratigraphic information. The status of geologic 

mapping should be evaluated throughout the region and 

places identified where specialized geologic mapping, supplemented by shallow drilling, could contribute to understanding the seismotectonics of the region. A higr priority 

should be to compile and plot the pertinent current geologic, 

seismologic, and geophysical data on a topograrhic base 

map, similar to the now-outdated map of Heyl and McKeown ( 1978). Such a compilation would shmv spatial 

relationships among geologic, geophysical, and s~~ismicity 

patterns that are likely to be important but that may not be 

recognized on separate maps. Within the Mississippi 

embayment, poorly consolidated, generally unrleformed 

sedimentary rocks conceal structural relationships and faults 

in the bedrock. However, outside the Mississipp; embayment, bedrock mapping may complement and co:'Toborate 

some structural interpretations that are based on geophysical 

data. 

Detailed investigations of deep structure in the rift 

should continue as the new studies outside the Redfoot rift 

begin. Faults associated with the rift probably constitute the 

greatest seismic threat to the region. Therefore. detailed 

studies of structures that are apparently associated with 

seismicity, such as the Blytheville and Pascola arches. are 

imperative. Such studies would utilize a variety of geophysical techniques to define the extent and understand the 

origin of major structures in the rift that are associated with 

seismicity. Mapping these structures would re'luire the 

acquisition of additional seismic-reflection data. An extensive petroleum-exploration program in the Reelfoot rift in 

the early 1980's included the collection of almost 4,000 mi 

of seismic-reflection profiles. These data cover many of the 

most active parts of the New Madrid seismic zore and are 

available for purchase, but new data would have to be 

The Plan: Preparing for the Next New Madrid Earthquake 23 
acquired over the Pascola arch and some other parts of the 

zone to improve understanding of the relationship between 

structure and seismicity. 

Recent work in the New Madrid seismic zone has 

suggested that the crust in the most active part of the region 

is characterized by low seismic-wave velocities and high 

seismic-wave attenuation (Al-Shukri and Mitchell, 1987, 

1988; Hamilton and Mooney, 1990). These properties may 

provide a criterion for evaluating whether a fault zone is 

capable of producing large earthquakes. 

To date, very little effort has been made to evaluate 

the seismogenic potential of the major faults along the 

margins of the Reelfoot rift. If the rift-bounding faults are 

seismogenic, then Memphis would be only a few tens of 

miles from the epicenter of a potential large earthquake. 

Densely populated Shelby County, Tennessee, would lie 

even closer, and West Memphis, Ark., a community of 

30,000, actually straddles the southeastern rift margin. 

Seismic-reflection data and detailed geophysical data are 

essential in evaluating the earthquake potential of major 

faults related to the rift margins. 

To assess the seismogenic potential of deep faults that 

appear to extend close to the surface on seismic-reflection 

profiles, detailed studies using high-resolution seismicreflection profiling and exploratory trenching, if appropriate. should be made. These studies would determine 

whether the faults deform young sediments near the surface 

where the resolution of conventional reflection data diminishes and thus constrain the likelihood of damaging earthquakes in specific source zones. 

Because much of the New Madrid seismic zone is 

covered with soft sedimentary rocks, deep scientific drilling 

offers the only means of directly sampling and measuring 

the physical properties of the bedrock to depths that 

approach hypocentral depths. Better information on the 

properties of these rocks will contribute to improved interpretations of aeromagnetic, gravity, and seismic data. This 

information also will help determine the factors that affect 

the way seismic energy is attenuated as it propagates 

through these rocks in the uppermost crust. A deep drill 

hole would permit direct measurement of the orientation 

and possibly the magnitude of the modem stress field in the 

New Madrid region, which is the driving force for the 

seismicity. Much of the data and information derived from 

a deep drill hole are unique and cannot be obtained in any 

other way. 

Objective 4.2: Determine the spatial and temporal characteristics 

of damaging earthquakes in the New Madrid region 

ACTIVITIES 

a. Continue and expand efforts to identify and determine the age of prehistoric earthquakes by studies 

of paleoliquefaction, surface faulting, landslides, 

seismically induced disruption of lacustrine deposits, archeology, and dendrochronolo~y. 

b. Document land deformation produced by the 

1811-1812 and earlier earthquakes. 

c. Identify deep faults that potentially extend to the 

surface by means of seismic-reflection and other 

geophysical data; target these faults for shallow, 

high-resolution, seismic-reflectio'l studies, 

ground-penetrating radar, and (or) trenching. 

d. Determine the age of young sedimen+ary rocks on 

various alluvial terraces in the Missi~sippi Valley 

to improve understanding of rates of deformation. 

e. Evaluate the status of geologic mapping and determine if more or specialized mapping is needed. 

f. Conduct a comprehensive study of the fluvial 

geomorphology of the Mississippi Valley. 

Discussion of Objective 4.2 

The accounts of the New Madrid earthquakes provide 

a fairly complete picture of the sequence of events in 

1811-12 (Fuller, 1912), but the historical record offers no 

clues about the occurrence of strong earthquakes before 

1811. Fuller (1912) briefly discussed five pre-1811 earthquakes, but his information is too sparse to determine even 

if they were Mississippi Valley events. 

The historical record of earthquakes in nost parts of 

the world, including the United States, is too short to 

document the long-term behavior of seismogenic faults. Yet 

information on the locations and frequency of strong earthquakes in a region is vital to reliably assessing earthquake 

hazards. Because of the short historical reco:--d, geologic 

and archeological studies of prehistoric earthquake phenomena (paleoseismology) have played an increasingly important role in improving earthquake-hazard analyses and 

probabilistic hazard assessments. Thus, geolog::c studies on 

the locations, timing, and sizes of prehistoric earthquakes 

have successfully extended the historical seismicity record 

in many parts of the world. 

Unlike many earthquake-prone places in the Western 

United States, the surface expression of young faults in the 

New Madrid seismic zone is very subtle to nonexistent. 

Geologic studies to determine the recurrenc~ of major 

earthquakes and the locations and nature of surface deformation in the region can contribute a great deal to hazard 

assessments, but these studies are difficult to conduct 

because of the subdued and concealed expressic n of tectonism. 

The only fully reported geologic data on the recurrence of large earthquakes in the New Madric region are 

Russ's (1979) study of shallow faulting associated with the 

Reelfoot scarp, a 7-mi-long escarpment along the western 

margin of Reelfoot Lake in northwestern Tennessee. The 

10- to 30-ft-high scarp is a prominent physiogra?hic feature 

in the Mississippi Valley, where the topographic relief is 

24 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
otherwise very low. An exploratory trench across the scarp 

exposed numerous, small-displacement faults that are coincident with the scarp and revealed evidence of two strong 

earthquakes that predate the 1811-12 events (Russ, 1979). 

Stratigraphic relationships in the trench and radiocarbon 

dating show that both of the ancient earthquakes are less 

than 2,000 years old. Thus, the three strong earthquakes 

(1811-12 and the two older events) that have occurred at 

this site in the past 2,000 years imply an average recurrence 

interval of about 600 to 900 years for strong earthquakes 

but not necessarily for earthquakes of the size that occurred 

in 1811-12. 

The geologic recurrence estimate of 600 to 900 years 

is in the range of estimates based on statistical analysis of 

historical and modem seismicity; these calculations yield 

recurrence estimates for maximum-magnitude events that 

range from about 200 years to more than 2,500 years but 

cluster around 600 to 1,200 years (Johnston and Nava, 

1985, table 1). The wide range in the estimates from 

seismologic data and the paucity of constraints from geologic data demonstrate the need for greater efforts to 

determine the age of prehistoric earthquakes in the New 

Madrid seismic zone. 

Geologic data on the timing of prehistoric earthquakes throughout the entire New Madrid region are needed 

not only to estimate the likelihood of future major earthquakes but also to understand the rate and processes of 

strain accumulation and release in the region. The most 

direct recurrence information is derived from studies of 

faults that have repeatedly ruptured the ground surface 

during successive events. However, other than the study of 

the Reelfoot scarp, efforts to identify tectonically significant surface faulting have been unsuccessful, in part, 

because it is difficult for displacements in competent 

bedrock to propagate to the surface through thousands of 

feet of soft sediment. 

It is fortunate that geologic estimates of recurrence 

intervals need not rely solely on finding evidence of surface 

faulting. The 1811-12 events show that the strong ground 

motion and deformation from major earthquakes in the New 

Madrid region caused a variety of secondary geologic 

effects, including extensive liquefaction, earthquakeinduced landslides, and uplift and subsidence. Ancient 

earthquakes surely produced similar effects that would be 

preserved in the geologic record. Identifying and dating 

these ancient effects would provide crucial information 

about the recurrence of strong ground motion- and thus 

large earthquakes-in the New Madrid seismic zone. 

Recurrence information is of such great importance that 

novel methods of dating prehistoric earthquakes need to be 

fully explored. For example, Reelfoot and Big Lakes are in 

the epicentral area of the seismic zone. Strong ground 

motion during the 1811-12 events may have disturbed the 

well-stratified sediments in these lakes, both of which 

probably were enlarged or even formed by the 1811-12 

sequence. If sediment cores from these lakes show disruption from the 1811-12 events, deeper cores may reveal 

similar features caused by older earthquakes that C'Juld be 

dated. 

Dendrochronology, the study of annual grow+h rings 

of trees, might also be useful in dating prehistoric earthquakes in the region. The strong ground shaking during 

earthquakes probably broke large branches, disturb~d root 

systems, tipped trees, and caused temporary changes in the 

water table, all of which stressed the trees. If this 

earthquake-induced stress were severe enough, it would 

have been recorded in tree growth rings, which could be 

dated. Very little old-growth forest remains; what is left 

should be systematically inventoried to determine the feasibility of dendrochronologic paleoseismic researd'. 

Successfully obtaining recurrence information in the 

New Madrid seismic zone requires a strategy for locating 

the areas where evidence of prehistoric earthquakes is likely 

to be found. The areas that experienced substantial deformation in 1811-12 presumably suffered similar deformation 

during earlier events. Drainage patterns and the morphology 

of stream channels can be very sensitive indic"tors of 

tectonic deformation. Therefore, a first step in this strategy 

would be to analyze the fluvial geomorphology in the 

seismic zone to identify areas of significant deformation 

during 1811-12 and then to use this analysis as a basis for 

selecting sites for intensive investigations using techniques 

such as high-resolution seismic-reflection studies o .. exploratory trenching. An important related aspect of this geomorphic analysis would be to obtain better data on the age 

of alluvial and fluvial deposits in the Mississippi Valley to 

help determine the rates of deformation. 

Objective 4.3: Determine the rates and causes of active eustal 

deformation and improve understanding of the stress regime and 

tectonic setting 

ACTIVITIES 

a. Identify areas of strain accumulation and quantify 

accumulated strain by using geodetic data. 

b. Acquire information on the modem stress field 

that is independent of seismicity data (by using 

existing wells). 

c. Drill one or more research drill holes. 

Discussion of Objective 4.3 

Modem geodetic methods for determining rates of 

active crustal strain provide critical data about the occurrence of large intraplate earthquakes. The rate at which 

elastic strain energy is accumulating should be neasured; 

the relationship between such changes and earthquakes may 

provide a means for discriminating among regions where 

large intraplate earthquakes are likely to occur (and reoccur) 

and those where they are not. 

The Plan: Preparing for theNext New Madrid Earthql·~ke 25 
The opportunity to conduct this kind of research in 

intraplate seismic areas is facilitated by the presence of a 

comprehensive network of bench marks that have been 

accurately surveyed by triangulation techniques for many 

decades (in some cases, these networks extend back to the 

19th century) and by the recent development of accurate, 

relatively inexpensive surveying methods using the Global 

Positioning System (GPS). By using GPS, it is now 

possible to measure crustal strain efficiently by resurveying 

old triangulation networks as well as by establishing new 

baseline data for future surveys. 

One hypothesis frequently cited to account for intraplate earthquakes is that they occur in zones of extreme 

crustal weakness. To test this hypothesis, it is necessary to 

accurately map the orientation of the stresses in the Earth's 

crust. Although the ability to map the crustal stress field has 

improved markedly in the past decade, data coverage in 

areas such as the New Madrid seismic zone is quite sparse 

and completely inadequate to examine this hypothesis. It is 

now possible to obtain data on the orientation of the crustal 

stress field by making straightforward geophysical measurements in boreholes (for example, wellbore breakouts). 

These measurements could be made either in holes drilled 

for other purposes or in shallow holes drilled specifically for 

stress measurements. Such measurements would provide a 

greatly improved knowledge of the physical mechanisms 

responsible for intraplate seismicity. The advantage of 

wellbore breakout data is that they are independent of 

seismicity; the disadvantage is that they are confined to 

shallow crustal depths and generally do not sample the 

depths of principal seismogenic strain release. 

Goal 5: Improving seismic risk assessments 

ACTIVITIES 

a. Delineate seismic source zones. 

b. Identify areas expected to experience strong 

ground shaking. 

c. Identify areas having soil deposits that can amplify 

ground motion. 

d. Identify areas subject to ground failure. 

e. Identify areas vulnerable to flooding from levee or 

dam failure and eruption of water associated with 

liquefaction. 

f. Inventory high-occupancy hazardous buildings. 

g. Conduct analytical and experimental studies on 

the earthquake response of engineered facilities. 

h. Identify procedures to reduce vulnerability 

through structural and nonstructural means. 

1. Evaluate the 1988 editions of the seismic design 

provisions of the principal model building codes 

(that is, Standard Building Code, Uniform Building Code, National Building Code, and the 

NEHRP Recommended Seismic Design Provisions) and recommend adoption of th ~ code that is 

most relevant. 

j. Provide a data base for seismic zonation. 

Discussion of Goal 5 

Assessment of seismic risk requires three elements: 

an earthquake-hazards model, an exposure model (inventory), and a vulnerability model. A generic earthquakehazards model requires knowledge of ground shaking and 

its probability of nonexceedance, surface-fault rupture, 

earthquake-induced ground failure, and regional tectonic 

deformation. The exposure model, or inventory, involves 

the spatial distribution of population and various structures, 

including buildings, utility and transportatio.'l structures, 

hydraulic structures (dams, reservoirs, levees, and so on), 

and others. The vulnerability model is a means for predicting losses among the inventoried items. One element 

commonly used in a vulnerability model is a frr~ility curve, 

which shows the probability of damage versus the level of 

ground motion for a specific type of structur~. Predicting 

damage is very difficult for a variety of reasons: nonuniform 

design and construction, variability in material properties, 

changing design strength of aging structures, U'lcertainty in 

the level of ground shaking, uncertainty in structural 

response, and uncertainty in the response of seiiments that 

are susceptible to liquefaction, to name a few. 

Improved techniques are needed for estimating seismic risk in the Central and Eastern United States because 

development of the current methodology was based primarily on experience in high-seismicity regions of the Western 

United States. More attention should be devoted to structural materials and systems that are no longer used in 

locations such as coastal California because of their perceived inherent low resistance to earthquake shaking but 

that are still widely used in the central and east~rn areas of 

the country. The response of these materials and systems to 

both strong and moderate levels of ground motion will 

greatly influence the pattern of losses in a future, strong 

New Madrid earthquake. Nondestructive testing would be 

necessary in evaluating the response of such stLictures. 

Methods have been developed and apr1ied in the 

Western United States to predict the probability and geographic extent of landsliding that would be t:iggered by 

earthquakes of given magnitudes and locations. Such methods could be applied to the New Madrid seismic zone but 

only after detailed investigation to (1) determin~ the distribution of susceptible slopes, (2) model the ground shaking 

that those slopes would experience, and (3) develop computer models to simulate how the slope mate:-ials would 

respond to the strong shaking. A predictiYe map of 

earthquake-induced landslide susceptibility developed in 

this way could be combined with an exposur~~ model to 

26 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
obtain a landslide risk model for future New Madrid seismic 

zone earthquakes. 

MANAGEMENT AND COORDINATION 

An intensified study of the New Madrid seismic zone 

would be conducted under NEHRP, and standard NEHRP 

procedures would be followed in managing the study. Thus, 

the study would be incorporated in the overall plans of 

NEHRP, and the interagency coordinating groups would 

provide an overview of activities in the New Madrid region. 

Much of the work in the intensified study would be 

conducted by scientists in universities, State geological 

surveys, and private groups. The award of research grants 

and contracts would be based on peer review of research 

proposals. Thus, detailed allocation of funds among the 

various activities identified in this plan would depend on the 

peer-review process. 

In addition to the usual NEHRP procedures for 

managing regional studies, there is a need for stronger 

coordination of studies in the New Madrid region because 

of the large number of participating organizations. At least 

seven States (Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri, and Tennessee) are involved. Participating agencies from each State could include both their 

emergency planning groups and their geological surveys. At 

present, CUSEC coordinates some of the State activities. 

Research groups from several universities and the USGS 

also are involved; these groups need to jointly plan instrument and data-processing systems and to share data from 

these systems. Coordination among these groups could be 

facilitated in three ways: 

1. Establish a New Madrid seismic zone coordinating committee comprised of representatives of 

each group that has a substantial responsibility for 

conducting part of the intensified study. 

2. Hold an annual workshop to present results of 

activities and to plan future work. 

3. Encourage presentation of results at scientific 

meetings and publication of results in appropriate 

scientific journals and other documents. 

Although additional means may be needed, these steps 

would certainly provide effective- probably essentialways of coordinating the study. 

CONCLUSIONS 

Earthquakes in the New Madrid seismic zone pose a 

relatively high and generally unappreciated danger to the 

Central United States in comparison with that of other 

natural hazards. A recurrence of the magnitude 8 earthquakes that struck the area in 1811-12 would cause thousands of casualties, and damage could run as high as $50 

billion. unless communities reduce their vulnerability 

through improved preparedness and mitigation measures. 

Such an event could devastate the region in ninutes; 

rebuilding and recovery would take years. 

The probability of a magnitude 8 earthquake in the 

New Madrid region, although difficult to evaluate with 

currently available data. appears to be low-in the range of 

2. 7 to 11 percent in a 50-year period. An earthquake in the 

magnitude 6 to 6.5 range, which could cause heavy damage, has a 16- to 63-percent probability of occurr:ng in a 

15-year period; that probability increases to a 45- to 

97-percent probability in a 50-year period (table 2). Refining these probability estimates and reducing the uncertainty 

of the potential damage estimates are objectives of studies 

in the New Madrid seismic zone. 

The level of earthquake preparedness in the New 

Madrid region is low, primarily because earthquake:' are not 

perceived to be of great concern in comparison with other 

demands on resources. Consequently, although some exercises have been conducted to prepare for earthqual~e disasters, few land-use or structural design provisions have been 

implemented to guide new construction, and virt''ally no 

efforts have been made to deal with the numerous existing 

structures that are vulnerable to earthquakes (for example, 

unreinforced masonry buildings). 

One of the reasons for inaction in dealing with the 

earthquake threat is the uncertainty about the locations and 

frequency of damaging earthquakes. Current data have been 

used to make general estimates of the seismic risk, but those 

estimates contain relatively arbitrary assumptions r'ld large 

uncertainties. The lack of strong-ground-motion data for 

events exceeding magnitude 5 and the lack of a chronology 

of strong earthquakes that exceeds estimated recurrence 

intervals are the two data limitations that present the 

greatest uncertainties. 

An intensified research program would greatly 

improve the basic data needed to assess seismic risk in the 

Central United States; these data also would provi1e better 

estimates of where and how often future earthquakes are 

likely to occur and what types of physical effects to expect. 

This foundation of scientific information would provide a 

basis for government agencies and the private sector to 

improve building codes, to retrofit or remove dqngerous 

structures, to start earthquake awareness and education 

programs, and to improve preparedness planning. 

The intensified study of the New Madrid seismic zone 

should have five goals: 

1. Implementing earthquake-hazard mitigation measures. 

2. Improving preparedness for earthquakes of magnitude 6 or larger. 

3. Establishing a modem seismic network in the New 

Madrid seismic zone to monitor the sizes, locaConclusions 27 
tions, and characteristics of earthquakes and to 

determine the nature of the ground motions that 

they generate. 

4. Locating faults that could cause destructive earthquakes, determining the recurrence rates of earthquakes, and delineating areas of potential damage. 

5. Improving seismic-risk assessments. 

Implementation of this five-point program would provide 

the information necessary to improve the reliability of 

seismic-risk assessments for the New Madrid region. The 

scope of activities envisioned under this program could be 

undertaken at a funding level of $5 to $10 million a year, for 

5 years, after which time the status of earthquake-hazard 

information for the New Madrid region would be reexamined and the plan modified to reflect the improved status of 

each element. Coordination would be facilitated by establishin,a a New Madrid seismic zone coordinating committee, holding an annual workshop, and presenting results in 

publications and meetings. 

REFERENCES CITED 

Algermissen, S.T., 1990, Earthquake ground motion and economic losses in the central United States [abs.]: American 

Association for the Advancement of Science Annual Meeting 

Abstracts, p. 28. 

Al-Shukri, H.J., and Mitchell, B.J., 1987, Three-dimensional 

velocity variations and their relation to the structure and 

tectonic evolution of the New Madrid seismic zone: Journal 

of Geophysical Research, v. 92, no. B7, p. 6377-6390. 

---1988, Reduced seismic velocities in the source zone of 

New Madrid earthquakes: Bulletin of the Seismological 

Society of America, v. 78, p. 1491-1509. 

Coffman, J.L., von Hake, C.A., and Stover, C.W., eds., 1982, 

Earthquake history of the United States (revised ed.), with 

supplement, 1971-80: Boulder, Colo., National Oceanic and 

Atmospheric Administration and U.S. Geological Survey, 

Publication 41-1, 258 p. 

Federal Emergency Management Agency, 1985, An assessment of 

damage and casualties for six cities in the central United 

States resulting from earthquakes in the New Madrid seismic 

zone: Washington, D.C., Central United States Earthquake 

Preparedness Project, 313 p. 

Fuller, M.L., 1912, The New Madrid earthquake: U.S. Geological Survey Bulletin 494, 119 p. 

Grohskopf, J.G., 1955, Subsurface geology of the Mississippi 

Embayment of southeast Missouri: Missouri Geological Survey and Water Resources Report 37, 2d ser., v. 37, 133 p. 

Hamilton, R.M., and McKeown, F.A., 1988, Structure of the 

Blytheville arch in the New Madrid seismic zone: Seismological Research Letters, v. 59, p. 117-121. 

Hamilton, R.M., and Mooney, W.D., 1990, Seismic-wave attenuation associated with crustal faults in the New Madrid 

seismic zone: Science, v. 247 [in press]. 

Hanks, T.C., and Kanamori, H., 1979, A moment magnitude 

scale: Journal of Geophysical Research, v. 84, no. B5, 

p. 2348-2350. 

Hanson, R.D., 1986, Building research needs for earthquake 

hazards initigation measures in the central USA, in Hays, 

W.W., and Gori, P.L., eds., Proceedings of Conference 

XXXV; a workshop on earth science con<>iderations for 

earthquake hazards reduction in the Central United States: 

U.S. Geological Survey Open-File Report 86-425, p. 172. 

Heyl, A.V., and McKeown, F.A., 1978, Prelimirary seismotectonic map of central Mississippi Valley and environs: U.S. 

Geological Survey Miscellaneous Field Studies Map 

MF-1011, scale 1:500,000. 

Hildenbrand, T.G., 1985, Rift structure of the northern Mississippi embayment from the analysis of gravity and magnetic 

data: Journal of Geophysical Research, v. 90, no. B14, 

p. 12607-12622. 

Hopper, M.G., ed., 1985, Estimation of earth1uake effects 

associated with large earthquakes in the New 11adrid seismic 

zone: U.S. Geological Survey Open-File Report 85-457, 

186 p. 

Johnston, A. C. , 1990, The stable-continental-reghn earthquake 

data base, in Coppersmith, K.J., and others, eds., Methods 

for assessing maximum earthquakes in the cent':'al and eastern 

United States: Palo Alto, Calif., Electric Pcwer Research 

Institute Project RP-2556-12 [in press]. 

Johnston, A. C. , and Kanter, L.R. , 1990, Earthquakes in stable 

continental crust: Scientific American, v. 254, p. 68-75. 

Johnston, A.C., and Nava, S.J., 1985, Recurre1ce rates and 

probability estimates for the New Madrid seismic zone: 

Journal of Geophysical Research, v. 90, no. B8, 

p. 6737-6753. 

National Academy of Sciences, 1990, Assessing the Nation's 

earthquakes: The health and future of regional seismograph 

networks: Report of the Panel of Regional Networks of the 

Committee on Seismology, National Resecrch Council: 

Washington, D.C., National Academy Press [in press]. 

Nuttli, O.W., 1973, The Mississippi valley earthquakes of 1811 

and 1812-Intensities, ground motion and magnitudes: Bulletin of the Seismological Society of Am~rica, v. 63, 

p. 227-248. 

---1983, Average seismic source-parameter rela+.ions for midplate earthquakes: Bulletin of the Seismological Society of 

America, v. 73, p. 519-535. 

Obermeier, S.F., 1989, The New Madrid eart"quakes: An 

engineering-geologic interpretation of relict liquefaction features, in Russ, D.P., and Crone, A.J., edf'., The New 

Madrid, Missouri, earthquake region -Geological, seismological, and geotechnical studies: U.S. Geolcgical Survey 

Professional Paper 1336-B, p. B1-B114. 

Penick, J.L., Jr., 1981, The New Madrid earthquakes (revised 

ed.): Columbia, University of Missouri Press, 176 p. 

Rankin, D. W. , 1977, Studies related to the Charleston, South 

Carolina, earthquake of 1886-Introduction ani discussion, 

in Rankin, D. W., ed., Studies related to the Charleston, 

South Carolina, earthquake of 1886-A prelirrinary report: 

U.S. Geological Survey Professional Paper 102.8, p. 1-15. 

Russ, D.P., 1979, Late Holocene faulting and earthquake recurrence in the Reelfoot Lake area, northwestern Tennessee: 

Geological Society of America Bulletin, v. 90, 

p. 1013-1018. 

28 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 
U.S. Geological Survey, 1988, Probabilities of large earthquakes 

occurring in California on the San Andreas fault: U.S. 

Geological Survey Open-File Report 88-398, 62 p. 

Zoback, M.D., and Zoback, M.L., 1981, State of st-~ss and 

intraplate earthquakes in the United States: Science, v. 213, 

p. 96-104. 

References Cited 29 
APPENDIX:- NEW MADRID SEISMIC ZONE WORKSHOP PARTICIPANTS 

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

Beavers, James (Martin Marietta Corporation) 

Bologna, Antonio (Memphis/Shelby County Building 

Code Enforcement Board) 

Braile, Lawrence (Purdue University) 

Branton, Fiona (U.S. Senate Committee on Commerce, 

Science, and Transportation) 

Chang, T .S. (Memphis State University) 

Chin, Jer-Ming (Memphis State University) 

Chung, Wai-Ying (Memphis State University) 

Clarke, Timothy (Memphis State University) 

Crone, Anthony J. (U.S. Geological Survey) 

Dorman, James (Memphis State University) 

Fanning, Harold (Reaves & Sweeney, Inc.) 

Guccione, Margaret T. (University of Arkansas) 

Hall, William (University of Illinois) 

Hamburger, Michael (Indiana University) 

Hamilton, Robert M. (U.S. Geological Survey) 

Hanson, Robert (National Science Foundation) 

Hatcher, Robert D., Jr. (University of Tennessee) 

Hays, Walter W. (U.S. Geological Survey) 

Herrmann, Robert B. (St. Louis University) 

Hester, Norman C. (Indiana Geological Survey) 

Heigold, Paul (Illinois State Geological Survey) 

Hildenbrand, Thomas G. (U.S. Geological Survey) 

Hill, William T. (Tennessee Department of Conservation) 

Howe, Warner (Gardner & Howe Structural Engineers) 

Hughes, Terry (Memphis/Shelby Co. Code Enforcement) 

Hwang, Howard (Memphis State University) 

Jacob, Klaus H. (Lamont-Doherty Geological 

Observatory, Columbia University) 

Jibson, Randall W. (U.S. Geological Survey) 

Johnson, Gary D. (Federal Emergency Management 

Agency) 

Johnston, Arch C. (Memphis State University) 

Kanter, Lisa R. (Memphis State University) 

Kernen, Michael (Tennessee State Representative) 

Kiefer, John (Kentucky Geological Survey) 

Krinitsky, Ellis (U.S. Waterways Experiment Station) 

Lanelle, Kathleen 

Lew, H.S. (National Institute of Standards and 

Technology) 

Masse, Robert P. (U.S. Geological Survey) 

McCrary, Tom (Memphis State University) 

McFarland, John David (Arkansas Geological 

Commission) 

McKeown, Frank A. (U.S. Geological Surv~y) 

McMullen, Richard (U.S. Nuclear Regulato"')' 

Commission) 

Mitchell, Brian J. (St. Louis University) 

Murphy, Andrew J. (U.S. Nuclear Regulatcry 

Commission) 

Murphy, Loyal (P.E.) 

Newton, Danny (Tennessee Emergency Management 

Agency) 

Nishenko, Stuart P. (U.S. Geological Survey) 

Obermeier, Stephen F. (U.S. Geological Su':'vey) 

Padovani, Elaine R. (U.S. Geological Surve:r) 

Palmer, James (Missouri Geological Survey) 

Paul, James (U.S. House Committee on Science, Space, 

and Technology) 

Reiter, Leon (U.S. Nuclear Regulatory Commission) 

Russ, David P. (U.S. Geological Survey) 

Ryland, Harvey (Central U.S. Earthquake Consortium) 

Schweig, Eugene S. (Memphis State Univers~ty) 

Sexton, John L. (Southern Illinois University) 

Sharrocks, Fred (Federal Emergency Manag~ment 

Agency) 

Shedlock, Kaye M. (U.S. Geological Survey) 

Stauder, William, S.J. (St. Louis University) 

Stevens, Jill (Memphis State University) 

Stewart, David (Southeast Missouri State University) 

Street, Ron (University of Kentucky) 

Suiter, Lacy (Tennessee Emergency Managem~nt Agency) 

Sutter, John (U.S. Geological Survey) 

VanArsdale, Roy B. (University of Arkansaf) 

Vaughn, James (Missouri Geological Survey) 

Wesnousky, Stephen G. (University of Nevada, Reno) 

Wesson, Robert L. (U.S. Geological Survey) 

Whitcomb, James (National Science Foundation) 

Zoback, Mark (Stanford University) 

30 Tecumseh's Prophecy: Preparing for the Next New Madrid Earthquake 

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c 

:x-