GOALS, STRATEGY, AND TASKS 

OF THE EARTHQUAKE HAZARD 

REDUCTION PROGRAM 

By Robert E. Wallace 

G E 0 L 0 G I C A L 5 U R V E Y C I R C U L A R 70 I 

J914 
United States Department of the Interior 

ROGERS C. B. MORTON, Secretary 

Geological Survey 

V. E. McKelvey, Director 

First printing 1974 

Second printing 1 97 4 

Free on application to the U.S. Geological Survey, National Center, Reston, Va. 22092 
PREFACE 

This description of the Earthquake Hazard Reduction Program of the 

U.S. Geological Survey (USGS) is intended to serve as a guide, a point 

of departure perhaps, for those involved ·in dkecting the program as well 

as a means of informing other agencies and individuals about its general 

scope. 

The program is designed to provide the background data and understanding needed to reduce ea:rlhquake hazards. Goals are set, technical 

and scientific strategies for reaching those goals are sug.gested, and a selection of specific tasks to be undertaken w~ithin the next several years is 

tabulated. 

In September 1973, the earthquake research programs of the National 

Oceanic and Atmospheric Administration (NOAA) and the USGS were 

administratively merged. The com,bined program under the USGS constitutes the single largest research and data-gathering effort in earthquake hazard reduction in the United States (.see organizational charts, 

p. 26) and includes the major efforts of the Federal Government in earthquake-related studies in seismology, geology, geophysics, as well as important efforts in soils engineering. The new USGS program includes 

seismic-~ngineering-data gathering and research conducted for the N ationa! Science Foundation, which has the principal Federal responsibility 

for earthquake-engineering research. In addition, the USGS program 

interfaces with, serves, or assists efforts in many other Federal, State, 

and local agencies and provides financial support for substantial research 

in academic institutions and some State and local agencies. 

The program as d~scribed is more an .ideal to be pursued within the 

next few years, given ·adequate funding, rather than simply a statement 

of what is currently underway. The ex,isting program ha·s evolved over the 

past decades under the administrative guidance of several agencies, some 

parts under the U.S. Coast and Geodetic Survey and its successors, the 

Environmental Science and Services Administration and NOAA, and 

other parts under the USGS and its subdivisions-the Office of Earthquake Research and Crustal Studies, the Office of Environmental Geology, 

the Office of Mar,ine Geology, and the National Center for Earthquake Research. Each organizational unit has left its mark on the program. 

An opportunity now exists to mold a more effective and better balanced program. But, g.iven the breadth and diversity of program requirements and potentials, ranging from physical science to sociology, from 

earthquake forecasting to earthquake engineering, and from the most 

basic research to administrative appl·ication, the challenge will be to arrive 

at something approaching concensus as to proper emphasis. What should 

be the dollar and man-power expenditure on each of the various components of the program? How can support be developed for work largely 

III 
neglected to date, or additional support be g·ained to ex:pand a sm.aU ongoing effort to a critical level? 

Several dozen scientists and engineers, including members of the Advisory Panel to the National Center for Earthquake Research (now the 

USGS Earthquake Studies Advisory Panel) have contributed to or reviewed this program statement. In the process of combining the ideas of 

all these individuals, the author undoubtedly has compromi,sed some 

strongly held opinions. 

Robert E. Wallace 

IV 
CONTENTS 

Page 

Preface ----------------------------------------------------------------- III Introduction ________________________ -·- __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ __ __ ___ _ 1 

Strategy of earthquake hazard reduction and modification ------------------- 1 

Land-use planning --------------------------------------------------- 3 

Engineering design and practice ------------------------------------ 3 

Prediction and control ----------------------------------------------- 4 

Insurance ----------------------------------------------------------- 6 

Emergency preparedness and response -------------------------------- 6 

Risk, vulnerability, and public information ----------------------------- 7 

Earthquake Hazard Reduction Program ----------------------------------- 9 

Earthquake hazard mapping and risk evaluation ------------------------ 11 

Earthquake prediction research and implementation --------------------- 14 

Earthquake modification and control ---------------------------------- 16 

Seismic engineering -------------------------------------------------- 17 

Earthquake information services -------------------------------------- 19 

Postearthquake studies --------------------------------.--------------- 20 

Application and demonstration projects -------------------------------- 21 

Extramural grants and contracts ----------------------------------------- 22 

Geographic distribution of effort in United States -------------------------- 22 

International programs and cooperation ----------------------------------- 23 

The Worldwide Network of Standard Seismographs--------------------- 23 

USA-USSR cooperative program in earthquake prediction --------------- 24 

Other international programs ----------------------------------------- 24 

Earthquake engineering ----------------------------.---------------------- 24 

Land-use planning __________________________ --------- _____ ----- _____ ----- 25 

Emergency preparedness and response ------------------------------------- 25 

ILLUSTRATIONS 

Page 

FIGURE 1. Diagram showing annual costs of construction and earthquake 

safety measures ------------------------------------------ 2 

2. Flow chart of output from fundamental Earth-science research to 

application in earthquake hazard reduction ----------------- 3 

3-8. Photographs of: 

3. 1906 earthquake-caused offset of road, Tomales Bay, Calif_ 4 

4. Landslide cracking on cliffs at Daly City, Calif., along 

San Andreas fault ---------------------------------- 5 

5. Comparative earthquake damage on different types of 

ground at Varto, Turkey ---------------------------- 6 

6. 1964 earthquake-caused landslide at Turnagain Heights, 

Alaska --------------------------------------------- 7 

7. 1971 earthquake damage to Van Norman Dam, San Fer· 

nando, Calif ---------------------------------------- 8 

8. Bodega Bay, Galif., nuclear-reactor site abandoned because of geologic fault hazard. ----------------------- 9 

9. Diagram showing earthquake prediction by changes in speed of 

seismic wave and "gaps" in movement along fault ---------- 10 

10. Histogram of earthquake frequency at Rangely oilfield, Colorado-- 11 

v 

Goals, Strategy, and Tasks of the 

Earthquake Hazard Reduction Program 

of the U.S. Geological Survey 

By Robert E. Wallace 

INTRODUCTION 

Earthquakes pose a serious and growing 

threat to the Nation. Of all natural disasters, 

earthquakes can cause the largest property 

damage and loss of life. A great earthquake 

(magnitude l~arger than 8) in the densely populated areas of the Pacific coast could cause 

damage in the range of tens of billions of dollars and the loss of thousands of Uves. The 

probability of such an event is high. The best 

estimate of the long-term average rate of occurrence of great earthquakes along the San 

Andreas fault is about 1 per 100 years. The 

last such event was 70 years ago, so that a 

significant probabHity exists of another within 

the next 30 years. Significant additional losses 

can .be expected with a higher degree of certainty from smaller earthquakes. 

Potential earthquake disasters are not limited to the Pacific coast. Great earthquakes 

have also occurred in the Mississippi Valley 

and along the eastern seaboard. The St~ Lawrence Valley, New England, and the Rocky 

Mountains have also been the sites of significant seismicity. 

The goals of the national earthquake program are to reduce the hazards to life and 

property, to mitigate human suffering and economic losses, and to minimize disruptions of 

business, government, ·and private activities 

from future earthquakes. The hazards, however, can never be reduced to zero, and analyses 

of vulnerability or risk must be prepared to 

assist the public in developing a rational ap1 

proach and reasonable attitude toward the risk. 

A major ,goal is to achieve an optimum balance 

between safety and economic cost (fig. 1). As 

an indication of cost, approximately $100 billion were spent on construction in 1973. If 

only 1 percent addi,tional cost were imposed in 

the interest of earthquake safety, more than $1 

billion annually would be the price. Thus inappropriate or inadequate mitigation methods 

could be extremely wasteful, but to sacrifice 

tens of thousands of lives needlessly would be 

gross negligence. Only through the development 

of sound scientific and engineering principles 

and practices can the system be adjusted for 

optimum benefit. 

STRATEGY OF EARTHQUAKE HAZARD. 

REDUCTION AND MODIFICATION 

Earthquake hazards are being reduced by incorporating earthquake resistance in structures, and advancement of proper engineering 

methods can greatly reduce the hamrds still 

further. The judicious use of land through zoning holds promise of reducing the hazard significantly. Earthquake prediction can open the 

way for a wide variety of actions to prepare 

for an impending emergency, and techniques to 

limit the size of an earthquake could significantly reduce the impact of earthquakes. The 

capa!bility to determine accurately a low or zero 

probability of earthquakes in some regions 

could save billions of dollars in the costs of 

construction and could prov,ide assurance of 

the safety of critical structures .such as nuclear 
CUTTING COSTS OF SAFETY 

ANNUAL COST OF CONSTRUCTION, 1973 

$100 BILLION 

COST OF EARTHQUAKE SAFETY 

MEASURES MAY AMOUNT TO 

$ 0-10 BILL I ON 

S0-10 BILLION SAFETY 

;a ~~----'•aa 

Figure 1.-Cutting costs of safety. Advancing earthquake science and engineering can increase 

safety and reduce the cost of safety measures. More appropriate building codes and better landuse policy can minimize the cost of hazard reduction measures. 

reactors. Earthquake insurance oan spread the 

economic losses of a disaster minimizing the 

impact on the individual, and emergency preparedness can ensure prompt and efficient 

amelioration of human suffering and economic 

loss. 

The program of earthquake hazard reduction must encourage the development of basic 

2 

concepts and understanding in the earth sciences and engineering and provide for an efficient flow of the developing concepts into application in hazard reduction processes (fig. 2). 

This calls for a multitdiscipline, multi-institution undertaking and a continuing appr.aisal 

of the interaction of all. In large measure, the 
RESEARCH QUESTIONS RESEARCH GOALS APPLICATIONS 

WHERE will earthquakes occur? 

~ ~ ENGINEERING 

EARTHQUAKE WHEN will earthquakes occur? r-- - (probability, forecasting, r- ~ PREDICTION LAND-USE PLANNING 

etc.) 

~ EARTHQUAKE HAZARD ~ EMERGENCY PREPAREDNESS HOW will land behave? 

-(ground shaking, ground _, EVALUATION AND MAPPING r7 AND RESPONSE 

failure, etc.) -

EARTHQUAKE INSURANCE WHAT physical mechanisms cause - earthquakes? MODIFICATION & CONTROL r-- -i 

(stress, strain, energetics, - etc.) 

~ PUBLIC INFORMATION 

FIGURE 2.-Flow of output from fundamental research in Earth sciences to application in earthquake 

hazard reduction. 

current inadequacy of fundamental understanding of the Earth processes and Earth reactions 

~ssociated with earthquakes and of the response of engineered systems permits only inadequate response through engineering and 

public decision-making processes, but measures 

that are being taken to reduce hazards should 

be encouraged. 

A common fallacy in the establishment of 

program priorities is to overemphasize the immediate need to apply existing scientific and 

technological knowledge. Such a priority is 

axiomatic, but generally the inadequacy of the 

basic knowledge is the key to its nonuse. The 

priorities of expediency and immediacy should 

not be permitted to obscure or obstruct the 

long-term growth of basic understanding and 

its orderly application. 

The major approaches to hazard reduction 

are: 

Land-use planning.-All the hazards of 

earthquakes stem from certain behavior of the 

3 

ground-ground breaking along faults (figs. 3, 

4), ground motion (fig. 5), ground failure including landsliding (figs. 4 and 6) and differential settlement, and ground-level changesor from water bod.ies disturbed by ground motion (fig. 7). Theoretically, these factors can 

be expressed in map form, and thus the use of 

land can be planned to take these factors into 

account and reduce hazards. For example, critical facilities such as nuclear-power reactors 

(fig. 8), hospitals or high-occupancy structures 

such as apartment buildings should not be 

placed directly astride active faults, and ground 

subject to the most severe shaking might better be used for recreational areas rather than 

for high-rise buildings, which result in dense 

occupancy. Communities can implement longrange plans by governing land use through zoning ordinances and grading codes. Grant agencies can require incorporation of seismic elements in land-use planning. 

EngineeTing design and pmctice.-Inasmuch 

as the most immediate hazard of earthquakes 
FAULT HAZARD 

FIGURE 3.-Fault hazard. The hazard of movement on faults can be reduced by prohibiting structures for human occupancy directly astride known active faults. Thi-s photograph, taken after the 1906 San Francisco 

earthquake, shows offset of a road \:l,;r more than 20 feet along the San Andreas fault., Tomales Bay, Calif. 

results from collapse of manmade structures, 

building of structures that are resistant to 

ground shaking and movement accompanying 

an earthquake will reduce the hazard. Three 

steps are critical : ( 1) the appraisal of the possible magnitude of ground motion must be 

sound; (2) the structural design must be adequate; and ( 3) the design must be executed 

properly in practice. The great variety of structures and uses of structures, ranging from 

high-rise buildings and dams to underground 

utilities, pose a complex problem. Important 

structures such as hospitals, fire-fighting facilities, and communication centers must remain 

operational in the event of a serious earthquake; 

thus engineering considerations ar~ more complex and demanding for such structures. Communities can employ building codes and standards to ensure public safety through earthquake-resistant structures, and loan agencies 

can require incorporation of standards that will 

minimize economic loss. Ordinances governing 

nonconforming structures, particularly those 

likely to collapse, can be developed and enforced. 

Prediction and contTol.-An analogy between 

weather prediction and earthquake prediction 

4 

is -instructive. The value of weather prediction 

or forecasting and hurricane and tornado warning has been clearly demonstrated over the 

years, despite the yet-imperfect understanding 

of atmospheric phenomena. Similarly, earthquake prediction, including the elements of 

what, where, when, and estimates of the reliability of the prediction or forecasts, can have 

great economic and social benefit. Numerous 

lines of research give promise that forecasting 

(fig. 9) of at least some specific earthquakestheir expected time, magnitude, and placeshould become feasible withi:t the next several 

years. As earthquake prediction and foreoasting improves, the public use of techniques to 

reduce the hazard will be more immediate and 

appropriate. Building codes and land-use controls will be put into practice more readily if 

long-term forecasts are a reality, and insurance 

can be more appropriately tailored in cost and 

coverage to the real needs. Emergency preparedness can be more effectively and economically 

administered. The concept of earthquake control (fig. 10) implies the eventual possibility of 
LAND-USE PLANNING 

FIGURE 4.-Land-use planning. Houses should not have been built astride the 1906 break of the San Andreas 

fault or on potential landslide developing in crushed rock along the fault zone. Photograph along San Andreas fault, Daly City, Calif. Heavy line is position of 1906 fault break; dotted line is approximate boundary of fault zone. 

relieving tectonic stresses on faults and thereby 

reduoing the catastrophic effect of earthquakes. 

The size of earthquakes theoretically could be 

reduced, or the potential for an earthquake 

might be eliminated or postponed. In the immediate future, it is necessary to know more 

5 

preoisely how to avoid inadvertent tr,iggering 

of earthquakes-which, unfortunately, has happened-in the development of waste-disposal 

wells, reservoirs, and other activities of man. 

Techniques to be developed under this program 

conceivably could be applied to triggering slip 
LAND-USE PLANNING 

FIGURE 5.-Land-use planning. Damage on different types of ground may be V·ery different. At Varto, Turkey, 

12 of 14 buildings on "old channel" material collapsed. On "bench" material no buildings collapsed. 

on potentially active faults and thus reducing 

the possibiUty of a damaging earthquake. 

Insurance.-Insurance cannot directly reduce 

the total hazard of earthquakes, but it can 

spread the risk and the economic impact of a 

disaster. Furthermore, it has, or can have, the 

effect of encouraging adoption of hazard-reduction measures. The insurance capacity of all 

private companies combined cannot cover a potential loss of between $10 and $40 billion, the 

amount of loss that can be expected from one 

major earthquake occurring in a major urban 

area. As a result, even though earthquake insurance is available, it is not aggressively sold, 

and the number of policies in effect covers only 

a small fraction of potential damage. The N ationa! Flood Insurance Act includes many procedures that might be modified and applied to 

6 

earthquake insurance. Hazard-mitigation methods must be coupled to any insurance program; 

otherwise, insurance can tend to encourage unsafe pra,c.tices. In order to make earthquake 

insurance more feasible, the Earth sciences 

must develop a far more quantitative and precise prediction of the characteristics and distribution of earthquake effects, including maps 

and analyses of these factors. 

Emergency prepat"edness and response.-

Many preventive and protective measures can 

be taken before an emergency to reduce the 

hazards of an earthquake, and plans can be 

prepared for prompt, efficient handling of casualties and problems after an earthquake. Communications systems, such as between hospitals 

and police units, can be developed, serums and 

medicines can be stockpiled, and alternate 
LANDSLIDE HAZARD 

FIGURE 6.-Landslide hazard. Landslides triggered by earthquake shaking constitute one of the most severe hazards of earthquakes. Techniques of identifying unstable ground coupled with land-use zoning can reduce 

the hazard. Photograph shows landslide area at Turnagain Heights, Anchorage, Alaska, after the earthquake of 1964 (U.S. Army photo). 

transportation routes can be planned. Exercises 

and tests designed around earthquake scenarios 

are becoming standard practice to develop a 

continuously updated plan of administrative ac7 

tion by an ever-changing group of public officials. 

Risk, vulne'rability, and public information.-

The public needs a far better evaluation of the 
INDIRECT HAZARD 

FIGURE 7.-Lndirect hazard. Van Norman Dam almost collapsed in the San Fernando earthquake of 1971. If it 

had, tens of thousands would have drowned. 

risk to which they are exposed from earthquakes. In the absence of a credible realistic 

evaluation, the response of individuals ranges 

from panic to complacency. With this confu8 

sion, communities and public bodies cannot respond entire.ly rationally, and the adoption of 

even simple hazard reduction practices is very 

difficult. If reliable assurance could be given of 
NUCLEAR POWER DEVELOPMENT DELAYED 

BY EARTHQUAKE HAZARD 

FIGURE B.-Nuclear power development delayed by an earthquake hazard. Because of the fault hazard, this site 

for a nuclear reactor at Bodega Bay, Calif., was abandoned after expenditure of millions of dollars and 

years of time in site preparation. If data on the fault had been available, the waste of time and money 

could have been avoided. 

low- or no-earthquake hazard in some regions, 

billions of dollars in construction costs might 

be saved. Dissemination of existing information 

to the general public is of high priority, and 

additional 'appraisals of risk and vulnerability 

are prerequisites to improved public response. 

EARTHQUAKE HAZARD REDUCTION 

PROGRAM 

The Earthquake Hazard Reduction Program 

of the U.S. Geological Survey is designed to 

carry the major Federal responsibility for 

earthquake-related research in the Earth sciences, both basic and applied, that is required 

for earthquake hazard reduction. The program 

will emphasize the development of basic understanding of fundamental seismological, geophysical, geological, tectonic, and soil mechanics 

principles without which the cumulative state 

9 

of the sciences cannot adequately serve practical needs. A balance of effort, however, will 

be sought between fundamental and applied 

studies to ensure an efficient transfer between 

the two. A program of seismic engineering financed by the National Science Foundation is 

conducted by the USGS. In addition, the program is intended to be responsive to the needs 

and programs of numerous other Federal agencies concerned with the hazards of earthquakes. Among these agencies are the Federal 

Disaster Assistance Administration, Atomic 

Energy Commission, Advanced Research Projects Agency, Department of Housing and Urban Development (HUD), National Bureau of 

Standards, Veterans Administraton, Department of Health, Education and Welfare, Department of Transportation, Bureau of Reclamation, and the U.S. Army Corps of Engineers. 

The program of the USGS will be implemented 

by utilizing not only the internal research capa-
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3t 

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0.. 5.0 

MONTHS 

8. BY "GAPS" IN MOVEMENT ALONG FAULT 

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100 10 20 30 

Kl LOMETER S 

FIGURE 9.-Earthquake prediction. A, By changes in speed of seismic wave. Speed of Pwave may decreas'e for months before an earthquake, then rise to normal just before 

the earthquake. B, By "gaps" in movement along fault. Microearthquake mapping identified slip surfaces on the San Andreas fault related to four moderate earthquakes 

(magnitude 4-5). A "gap" suggest:" that the next slip and a related earthquake will 

lie between others. 

bilities of the USGS, but also those of the 

universities, States, and the private sector. A 

major program of grants and contracts will 

assist these extramural efforts. 

The goals, approach, and specific tasks are 

described in the following pages for €ach of 

the major elements of the USGS program: (1) 

earthquake hazard mapping and risk evaluation, (2) earthquake prediction, (3) earthquake 

modification and control, ( 4) seismic engineer10 

ing and, in addition, the program of strongmotion instrumentation, which the USGS conducts in cooperation with the National Science 

Foundation, and (5) earthquake information 

services. The major program elements are 

served by supplementary efforts described under (6) postearthquake studies and (7) application and demonstration. The geographic distribution of effort needed within the next few 

years is also indicated. 
E.ARTHQUAKE CONTROL 

EARTHQUAKE FREQUENCY AT RANGELY OIL FIELD, COLORADO 200~-----------------------------------------------------------,sooo 

i All earthquakes 

Quakes within 1 kilometer of bottom 

of experimental wells 

150 ;;; 

~ 

"" "' a.:: 

"" :;:) 

~ 

c "' "' "" :;:) a.:: 0 THRESHOLD NEEDED TO A. 

% 

~ INITIATE EARTHQUAKES a.:: a.:: 3000 0 c 100 > "" a.:: u. 

0 "" "' a.:: "" a.:: 

.a "" >- ~ 

_, 

% :;:) ~ 

z z 

0 

2000 ~ 

l- FLUID INJECTION •I• FLUID-4•....,, .. , ---FLUID INJECTION-----~ WITHDRAWAL 

FIGURE 10.-Earthquake control. The level of earthquake activity was controlled at Rangely oilfield, 

Colorado, as shown in this graph, by controlled pumping so that the reservoir pressure was either 

above or below a critical threshold level. 

EARTHQUAKE HAZARD MAPPING AND RISK 

EVALUATION 

GOALS 

• Develop the fundamental understanding of 

the physical behavior of rocks and soil under seismic conditions as a basis for mapping 

hazardous areas or defining hazardous situations and risk. 

• Identify, characterize, and map earthquake 

geologic hazards such as ground failure (including landsliding, liquefaction, landspreading, and differential settlement), surface 

faulting, tectonic elevation changes, and water-related effects including flooding, tsunamis, and seiches. 

11 

• Relate geologic and soils information to the 

problem of strong ground motion as discussed under "Seismic eng,ineering" section. 

• Define and evaluate seismic risk as a guide 

for engineering, social, and economic responses by the general public, industry, and 

government. 

APPROACH 

Two basic steps are involved in achieving the 

goals. The first is to develop techniques of characterizing, as quantitatively as possible, the 

physical factors of the Earth that influence the 

hazardous behavior of the ground. The seeond 

is to map or otherwise identify these faetors so 
that the hazards and risk created can be minimized thvough proper land use, engineering design of structures, or other policy ·and administrative means. Maps must be developed in 

formats most useful for the engineer planner, 

or other users. 

For each of the haz!ard factors indicated, a 

somewhat diffe.rent level of knowledge exists. 

For some factors extensive fundamental research is still required, whereas others are well 

enough understood for hazard reduction measures to be employed. 

Strong motion 

At present, the distribution of strong g.round 

shaking on competent (or some other specified) 

rock during an earthquake can be estimated in 

terms of probability through an analysis of current seismicity (on the basis of both seismological and geological data) and attenuation of 

seismic waves. Maps prepared on this bas,is 

might be called regional seis·mic-risk maps. 

Ideally, maps showing the probability of specified levels of ground acceleration, velocity, and 

displacement, together with the duration of 

strong shaking, should be prepared. Maps of 

these types provide sufficient information for 

calculating the contribution of surfici,al geologic 

mate~ials and soils at each site to ground shaking, provided that certain critical physical 

parameters of these materials are known. 

The estimation of strong ground shaking in 

terms of probability may also be useful in the 

evaluation of liquefaction and landslide potential. Relationships between s.trong ground shaking and Hquefaction are fairly well known, so 

the probability of liquefaction could be mapped 

if the geological and engineering properties of 

the surficial materials at the site were known. 

QuanUtative relationships between ground 

shaking and land-sliding are not well known. 

Consequently, development of estimates of the 

probability of landsliding will depend on the 

success of future research. 

Although the goals of risk evaluation, hazard 

mapping, and seismic engineering each demand 

some unique approaches, the .scientific and technical studies for each interrelate and are mutually supportive. 

Su1·face faulting 

Active faults can be recognized remarkably 

well in reconnaissahce fashion by their geo12 

morphic expression as observed in aerial photography. Study of high-altitude photographs 

and side-looking radar. images provides reconnaissance evidence of faults. Lower altitude 

photographs, particularly those taken with low 

sun angle, then can provide the detailed evidence needed to evaluate the recency of movement. Examination on the ground, including 

trenching and drilling to expose evidence of 

offset of Holocene (recent) soil units can indicate· the amount, distribution, and recurrence 

of movement. 

Faults that cut the sea floor can be recognized by acoustical profiling techniques. Furthermore, these techniques can show whether 

or not the faults cut the up•permost or most 

recent sedimentary deposits, providing evidence 

of recent activity. 

Microearthquake studies based on dense arrays of short-period seismographs permit 

three-dimensional mapping of seismogenic sections of active faults as well as identification 

of "locked" sections of major known active 

faults. 

The combination of these techniques provides 

an effective method of mapping faults and 

evaluating their potential for surface movements. The main task of this phase of the USGS 

program is to carry out such mapping and 

evaluation. Priorities for carrying out the active fault mapping and evaluation will be governed by the projected development of urbanizing areas, by the economic importance of the 

development and by the relative hazard of different land utilization. For example, the need 

for nuclear power demands a high priority for 

early site evaluation of broad regions along 

the coast of California. 

Ground failure 

Slopes that have failed by landsliding in the 

past can be identified by photogeologic means, 

but their response to seismic shaking in the 

future cannot be predicted accurately. Better 

understanding of the mechanics of slope failure 

is needed .so that mapping can express more 

precisely the expected behavior of a given slope. 

The approach of the program will be to carry 

out mapping of unstable slopes in reconnaissance as a first approximation of the extent of 

the hazard, while at the same time attempting 
through topical studies to improve the capability to predict behavior under different seismic conditions. 

The physical principles of liquefaction and 

differential settlement are known in a general 

way, but in most places the lithology and 

ground-water conditions are not known well 

enough to interpret the susceptibility to liquefaction and differential settlement. A general 

evaluation of the problem can be obtained in 

many areas by reconnaissance mapping of unconsolidated sediments, accompanied by analysis of existing data from water wells and agricultural soil maps. This type of mapping will 

be done first in selected areas where urban 

development is imminent. 

Tectonic elevation change 

Techniques are known for determining the 

past vertical changes of tectonic blocks, and 

the assumption can be made that the blocks 

are likely to continue to move in the same sense 

in future earthquakes. The techlliques include 

a variety of geomorphic methods such as the 

analysis of erosion surfaces, areas of deposition in bays or sedimentary basins, or geodetic 

records. 

Few analyses of expec,ted changes in vertical elevation relative to the earthquake hazard 

have been made, but such analyses should be 

carried out along coast lines where vertical 

changes can constitute the most severe hazards. 

W ater-·related efj ects 

The extent of flooding that might result from 

the collapse of a dam, either natural or manmade, can be estimated and maps prepared. 

Such map evaluations should be made in areas 

where flooding constitutes the most severe hazard to man. An engineering study should be 

included in the evaluation of manmade dams. 

Damming of rivers by earthquake-induced landslides is a significant hazard to consider in 

some areas. 

Geologic techniques can contribute to the 

study of past histories of tsunamis and seiches, 

and these techniques should be applied to evaluate factors of past runup and recurrence of 

these phenomena. 

13 

SPECIFIC TASKS 

• Make theoretical and field seismic studies of 

the influence of local geologic conditions on 

the amplitude, characteristics, and duration 

of strong ground shaking. 

• Make l~aboratory and field soil-mechanics 

studies of the response of surficial geologic 

materials to large cyclical strains. 

• Make studies of the statistical nature of 

earthquake occurrence, with emphasis on the 

nature of the distribution and the statistical 

treatment of aftershock sequences. 

• Conduct additional investigations of the historical seismicity of selected areas. 

• Investigate the nature of the attenuation of 

seismic waves in various parts of the country 

with emphasis on the Eastern United States 

and Alaska. 

• Prepare regional seismic risk maps of the 

earthquake-prone areas of the country. Initial efforts should be directed toward the 

preparation of maps of maximum acceleration (with associated probability) for a 

given return period. 

• Conduct research to define mappable parameters that consider the amplitude characteristics of ground motion as a function of frequency. 

• Compile and evaluate existing information 

on faults with known or suspected late 

Quaternary activity. 

• Map in reconnaissance active faults by photogeologic and other remote-sensing techniques in California, Nevada, Uta~1, Alaska, 

and other States where these techniques are 

applicable. 

• Develop and improve techniques to date recent geologic (Holocene) features for the 

purpose of determining long-term strain 

rates such as the recurrence of faulting and 

rates of landsliding. The techniques may include studies of pollen, tree rings, soil development, carbon-14 residues, sedimentary 

stru0tures, and others. 

• Map the activity of faults by microearthquake techniques. 

• Map active faults under the ocean by subbottom acoustical-profiling techniques. 

• Determine activity of faults by strain meters 

and other geodetic methods. 
• Study the soil profiles and recent geologic 

(Holocene) history of active faults to determine patterns, width, and other characteristics of active zones. 

• Map landslides that might be reactivated by 

earthquakes. 

• Develop techniques to determine factors that 

govern slope stability under seismic loading. 

• Analyze slope stability and make slope maps. 

• Map those geologic units that will influence 

the distribution of hazards such as liquefaction. 

• Do laboratory and field studies on liquefaction. 

• Map areas where the hazard of liquefaction 

is most severe. 

• Analyze geodetic , historic, geomorphic, and 

stratigraphic records to evaluate the haz.ards 

of potential changes in vertical elevation during an earthquake. 

• Map areas of potential flooding that results 

from seismically induced changes or damage 

to structures. 

• Apply geologic techniques to analyses of hazards of tsunamis, seiches, and surge phenomena, particularly recurrence and geographic distribution of past runups. 

• Prepare experimental maps similar to the 

"seis·motectonic maps" of the Soviet Union. 

• Prepare earthquake geologic-hazard maps 

suitable for determinations of land-use 

policy. 

• Study the effects of selected earthquakes to 

learn firsthand how theory and actual ground 

behavior relate. 

EARTHQUAKE PREDICTION RESEARCH AND 

Il\IPLEMENTATION 

GOALS 

• Develop the physical understanding and instrumental means required for forecasting 

the time, place, and magnitude of earthquakes and to implement and evaluate experimental earthquake prediction systems in 

highly seismic regions. 

• Develop the historical and geological background for estimating earthquake probability 

and recurrence characteristics. 

14 

APPROACH 

Many observations made in various parts of 

the world indicate that large earthquakes have 

been preceded by anomalous ground-surface deformation, an increase in local seismicity, variation in the composition of water from wells 

or springs, and other physical changes. Systematic seismic studies in search of precursor 

events, ~hich have been made near Garm in 

Tadj ikistan, USSR, have revealed apparent 

changes in the velocity of P-waves, in the elastic properties of rocks in the source region, and 

in the orientation of small earthquake fault 

sources before large earthquakes. Application 

of modifications of one of the Soviet techniques 

has been successful in the retrospective prediction of seve~al earthquakes in the United 

States. To a large extent, these leads, which 

give great promise for earthquake forecasting, 

represent an empirical approach. Indeed, given 

a sufficiently widespread and dense network of 

sensors to monitor changes that presage earthquakes and given sufficient experience, the empirical approach might be used successfully to 

forecast some earthquakes. But in the long run, 

data gathering and interpretation must be designed in the framework of a fundamental understanding of earthquake causes and mechanisms. As the fundamental understanding 

grows, the ability to forecast accurately will 

improve. Given valid models, the extremely significant evaluation of areas that will not have 

damaging earthquakes for specific periods of 

time should be possible. 

Principal requirements for the fundamental 

studies related to earthquake prediction include: 

• Accurate delineation of the physical properties and principal structural elements of 

the crust and up·per mantle in the study area. 

• Adequate monitoring of strain accumulation 

and release, microearthquakes, and other 

manifestations of earthquake-related changes 

in the region. (Deep in-situ stress measurements would be of great value but are not 

yet p·racticably obtainable.) 

• Detailed laboratory data on the behavior of 

rocks as a function of composition, temperature, confining and pore pressure, shearing 

stress, and strain rate over the ~anges of 
these variables found in the crust and upper 

mantle. 

• Rapid, effective methods of analyzing vast 

quantities of monitored field data and presenting the results for consideration in an 

actively updated computer-based model of the 

region. 

• Effective methods and adequate staff and 

computer facilities for maintaining and updating a dynamic computer-based model of 

the crust and upper-mantle earthquake-generating system, for evaluating the significance of monitored field data in terms of the 

current state of the model, and for formulating predictions of impending earthquakes. 

The concepts of global plate tectonics probably provide the correct outline of the processes that ultimately are responsible for earthquakes, but to be useful for prediction, that 

outline must be strengthened and fleshed out 

with many important details on the constitution and behavior of the boundary zones between plates that generate earthquakes. Some 

of these studies should be made under the 

earthquake hazard reduction program, but the 

overall pursuit of -plate-tectonic concepts should 

be as broad as all the Earth sciences combined. 

The first major prediction experiment has 

been. organized around an intensive coordinated microearthquake-, strain-monitoring-, 

tectonic-analysis program in a 50- by 300-

kilonteter region cut by the San Andreas fault 

system in central California. The immediate 

objective of the work is to delineate the major 

physic·al and kinematic features of the earthquake-producing crust-and-upper-mantle system and to develop efficient methods for recording and interpreting the most obvious symptoms of changes occurring within it, that is, 

earthquakes and strain changes. In addition, 

detailed and specific experiments are planned 

and are presently underway to test empirical 

and theoretical models for earthquake precursors. 

A worldwide search for premonitory effects 

will be made through cooperation with scientists of other countries. 

SPECIFIC TASKS 

Some tasks can be done with instruments and 

methods that are now ready for application. 

These include : 

15 

• Establish telemetered short-period seismic 

networks to locate microearthquakes (and 

thereby m·ap faults within the crust), to provide data on the physical properties and 

ela·stic regime of the crust, and to search for 

premonitory seismic-velocity changes in the 

crust surrounding the foci of impending 

earthquakes. 

• Install telemetered tiltmeters to monitor 

strain changes continuously at many locations to document slow deformation of the 

crust and to detect the onset of rapid changes 

that may precede earthquakes. 

• Employ surveying techniques (especially 

leveling and trilateration with the laser 

geodolite) to monitor gross regional deformation across the major fault zones, that is, 

to detect the relative movement of plates and 

platelets. 

• Install creepmeters and short aHnement arrays to monitor displacements within fault 

zones. 

• Do the geologic mapping and supporting 

studies to identify active faults, locate and 

date the most recent breaks, and evaluate 

other evidence of recent deformation. 

• Conduct laboratory studies of the physical 

properties and mechanical behavior of rocks 

under conditions found in the crust and upper mantle. 

• Simulate deformation and faulting in realistic Earth models by computer modeling. 

• Employ multiparameter correlation of recorded microearthquakes, strain patterns, 

strain events, and other features to search 

for evidence of propagation of strain or slip 

events through the network. 

• Use crustal-refraction seismic systems and 

portable seismograph networks for special 

topical studies of the Earth's structure, aftershock sequences, earthquake-source parameters, and similar features. 

• Use geothermal logging equipment and interpretive t·echniques to develop information on 

temperature as a function of depth (and 

position relative to the fault) in the crust 

and upper m·antle. 

• Analyze the geologic and tectonic characteristics of highly seismic areas in which experim·ental prediction will be conducted. 

• Carry out limited, exploratory deep drilling 
and direct exam,ination and instrumentation 

of fault zones at depth. 

• Analyze the geologic record of active faulting and tectonic changes, particularly of the 

last 50-100,000 years, in highly seismic areas. 

• Investigate the validity of earthquake-prediction methods developed in the Soviet 

Union, Japan, China, and other foreign countries. 

• Explore global systems of crustal plates and 

fractures that control earthquake generation. 

Some instruments and methods require further testing or de,velopment or are too costly 

for extensive use at present. Development of 

these are specific tasks that may be pursued. 

Examples are: 

• In-situ stress measurements by hydraulic 

fracturing or borehole strain-relaxation 

measurements. 

• Quartz-tube strain meters or other shortbase shallow-burial strain meters. 

• Multibeam laser-ranging instruments to increase the precision of free-8/ir-path distance 

measurements (possibly to a few parts in 

108 ). 

• Long-period, broad-band, large-dynamicrange seismographs to record a broader spectrum of ground motion for improved studies of earthquake sources. 

• Water-level recorders and volumetric-strain 

meters of high stability and sensitivity. 

• Stable high-sensitivity recording magnetometers to search for magnetic precursors to 

seismic events. 

• Widespread systematic monitoring of water 

composition at flowing springs or wells to 

search for geochemical precursors to earthquakes. 

• Extensive drilling and direct examination 

and instrumentation of fault zones at depth. 

EARTHQUAKE MODIFICATION AND CONTROl. 

GOALS 

• Determine the feasibility of limiting the 

magnitude of earthquakes on 8!Ctive faults. 

• Design subsurface waste-disposal operations 

and reservoir siting so as to prevent inoovertent triggering of earthquakes. 

APPROACH 

Theory and both laboratory and field experiments have shown that the frictional resistance 

16 

to shear failure in rock can be changed by altering the fluid pressure along potential or 

existing failure surfaces. By appropriately 

modifying fluid pressures along active faults, 

it is theoretically possible to strengthen and 

weaken the fault so as to prescribe in advance 

the maximum rupture length in an earthquake. 

The rupture length will be determined principally by the distribution of shear stress and 

the frictional strength (modified by fluid pressure) along the fault surface. For determining 

the required pattern of fluid-pressure changes, 

we rely on three-dimensional finite-element 

models of the fault zone in which the parameters of stress, fluid pressure, and material 

properties can be assigned arbitrarily. An existing nume,rical model predicts the distribution 

of pore pressure required to limit the fault 

length and determines additional source parameters such as magnitude of the earthquake, slip, 

and stress drop. Laboratory experiments will 

be conducted to simulate the numerical model 

and test the validity of the physical assumptions it contains. 

The complexity of natural fault zones will 

require models with a greater, but yet unknown, degree of sophistication. A field test 

similar to the laboratory experiment in concept, but on a scale of tens of meters, is therefore planned. A site for the experiment that 

contains an existing, appropriately stressed 

fault in a well-exposed outcrop, such as a 

quarry, will be sought. USGS and university 

investigators will collaborate in determining 

the state of stress and frictional properties of 

the rock. The fault zone will be instrumented 

for measurement of the static and dynamic 

strains generated by the earthquake induced. 

This cooperative project is intended to provide 

not only a field test of the feasibility of earthquake control but also a unique opportunity for 

understanding the relationships between the 

parameters of the earthquake source and testing models of earthquake precursors. 

If earthquake control is ever to be possible, 

the San Andreas fault zone must be amenable 

to the required alterations in its fluid-pressure 

regime, and test holes are planned for measurement of fluid transmissibility, in-situ stress, 

and material properties. In addition, a prototype intensive-monitoring experiment will be 
started on a limited part of the San Andreas 

fault. Detailed measurements of strain and 

seismicity and an analysis of the geologic structure will be made so that a finite-element computer simulation of the fault may be tested 

against observations. 

A search for an active fault in a suitably 

remote area will be undertaken. If the smaller 

seale experiments prove successful, the preparations for an active experiment will be considered. 

SPECIFIC TASKS 

• Develop effective economical techniques of 

measuring absolute in-situ stress. 

• Establish the mechanics of fluid flow through 

fracture systems in reservoirs. 

• Establish criteria for evaluating potential 

seismic hazards in planning waste-disposal 

sites and reservoirs. 

• Test accuracy of numerical methods for calculating fluid-pressure changes in fractured 

rocks by comparing with observations in the 

field. 

• Carry out small-scale (meters to tens of 

meters) field test of fluid injection. 

• Develop instrumental monitoring systems of 

selected areas that may be considered for 

future active testing. 

• Monitor and analyze selected fluid-injection 

projects that become available. 

• Monitor and analyze selected reservoir projects that may be developed. 

• Make intermediate- and large-scale laboratory tests of fluid-injection procedures in 

various rock types and under various conditions. 

SEISMIC ENGINEERING 

The seismic-engineering program is being 

conducted by the USGS largely in cooperation 

with other agencies. The principal financial 

support is from the National Science Foundation, and the strong-motion instrumentation 

programs of most other Federal, State, and 

local agencies are being coordinated through, 

or assisted by, this program. 

GOALS 

• Develop a basis for estimating the principal characteristics of strong ground motions 

to be expected from future earthquakes. 

17 

Spectral characteristics, attenuation rates, 

influence of source, travel path, and local 

site conditions are of special concern. 

• Determine the elastic and inelastic response 

of representative types of structures, and 

determine the influence of the foundation 

conditions on this response. Utilize these 

data to improve procedures for modeling the 

dynamic characteristics of structures and 

their response to earthquakes. 

• Coordinate the strong-motion instrumentation programs of Federal, State, and local 

agencies into a national strong-motion instrumentation program. 

• Cooperate with other agencies and engineering organizations in the develop·ment of 

seismic-design procedures and earthquake 

hazard analyses. 

APPROACH 

The major data-gathering effort of this program is through the deployment of strongmotion instruments. In the past, the greatest 

number of instruments have been placed in 

buildings, dams, or other structures, but more 

effort has been made recently to determine 

ground motion in free-field situations. Although 

numerous records have been obtained from the 

existing strong-motion instruments, the analyses and interpretations of these records indicate 

that the amount and type of data are inadequate. The Panel on Strong-Motion Seismology 

(Karl V. Steinbrugge, chairman). of the Committee on Seismology, National Research Council-National Academy of Sciences, recommended in 1973 "an immediate increase in the 

number of strong-motion instrument stations 

in the United -states by approximately 2,000 

with at least 500 of the new stations installed 

east of the Rocky Mountains." The panel also 

recommended "that the program be carefully 

planned so as to optimize its usefulness and 

effectiveness in all parts of the country" and 

emphasized an integrated approach ranging 

from pure research to applications with shortterm payoffs. 

The seismic-engineering program will draw 

heavily on data and interpretations developed 

under the prediction and hazard-evaluation 

programs. The nature of soil and geologic units 

and of seismic source and configurations are 
among the many inputs that must come from 

these companion programs. 

The coordination of the strong-motion instrumentation programs of several agencies had 

led to what can be considered a national program, but as yet an optimum program has not 

been achieved. A better distribution of instrumentation both geographically and by type of 

structure is needed. Cooperative efforts with 

other agencies and engineering organizations 

in the development of seismic-design procedures and hazards analyses has been very productive, and these efforts will continue. 

The planning of arrays of instruments to determine the nature of the ground motion is 

based on the seismic history and .antici,pated 

nature of the earthquake source for each region of the country. An appropriate balance 

must be achieved between the desire for a rapid 

accumulation of data from frequently occurring 

small events and the necessity to obtain an 

adequate amount of data for the less frequent 

major events. A high priority is being placed 

on arrays to determine the attenuation of motions from all earthquakes of magnitude 7.5 or 

greater. In conjunction with the ground-motion 

ar,ray.s, additional instrumentation that will be 

useful in the determination of the source parameters and source mechanism is planned. 

Because of the nonlinear nature of the response of soils and structures, data are sorely 

needed in areas in which damaging levels of 

motion occur. The influence of the flexibility 

of the foundation material on the response of 

structures is important. 

Two-thirds of the strong-motion accelerographs in the country have been installed to 

determine the response of structures (largely 

buildings and some dams). Most of these instruments have been purchased by other agencies, and many were installed by private building owners to satisfy code requirements. As 

a result, an optimum distribution of the instrumented structures has not developed even 

though the maintenance costs for these instruments have, in the past, been absorbed by the 

Federal program. These maintenance costs are 

being shifted to the instrument owners, which 

will permit a redirection of Federal funds into 

a series of more integrated and effective experiments. Since numerous outside agencies and 

18 

organizations have a primary interest in the 

instrumentation of structures, criteria and 

guidelines on structural instrumentation are 

being prepared. These will be circulated to 

various organizations and agencies for their 

review and information. 

In order to interpret the records obtained 

from the strong-motion instrumentation, the 

dynamic characteristics of the sites and structures must be known. Some documentation of 

the physical characteristics of each site and 

each structure is obtained at the time that the 

instruments are installed. This documentation 

must be supplemented by appropriate measurements of the dynamic properties of the 

sites and structures. Analytical investigations 

are being conducted in conjunction with the 

interpretation of the records and as a guide to 

the development of the instru,ment arrays. 

As the number of strong-motion instruments 

that record each earthquake has increased, a 

greater effort has been required to process the 

data quickly and accurately and disseminate 

them to the cooperating agencies and organizations. Several data-processing schemes are 

being investigated. In addition, the instrumentation and the format for recording the data 

are being continuously reviewed in the light 

of developments that might lead to improved 

data-processing procedures. T.he reports and 

publications that are used to list and to summarize the strong-motion data are being reviewed in order to evolve a more effective 

means of dissemination. 

SPECIFIC TASKS 

• Deploy two-dimensional arrays of strongmotion instruments to determine the spectral characteristics and attenuation of 

ground motion in regions where damaging 

earthquakes are most. likely to occur. 

• Deploy additional strong-motion instruments 

in dense two- and three-dimensional arrays 

to investigate the influence of local geology, 

soil conditions, and topography on the spectral characteristics and amplitude of strong 

ground motions. 

• Compile and evaluate the existing data on the 

spectral character,istics and attenuation of 

strong ground motions. 

• Conduct analytical investigations of the 
spectral characteristic-s and attenuation of 

surface motion to be e~pected from different 

earthquake sources. 

• Compile descriptions from existing information on the site characteristics of all strongmotion instrument sites. 

• Investigate the dynamic site characteristics 

at each site where a significant strong-motion 

record has been obtained. 

• Evaluate the influence of site conditions on 

the_ spectral characteristics and amplitude of 

strong ground motions. 

• Develop guidelines for the instrumentation 

of representative types of structures in order to determine their elastic and inelastic 

response to earthquakes. 

• Develop criteria for an optimum national 

program of instrumentation of structures. 

• In conjunction with the regional arrays in 

seismically active areas, install instruments 

in representative types of structures to determine their elastic and inelastic response 

to earthquake. 

• Compile available information on the analytically and experimentally determined dynamic characteristics of instrumented structures. 

• Measure the dynamic characteristics of all 

instrumented structures utilizing ambient 

vibrations. For selected structures, conduct 

forced-vibration tests to determine the nonlinearity in their elastic response. 

• Compile and evaluate the existing data on 

the response of structures to strong ground 

motions, particularly with respect to the nonlinear and inelastic response. 

• Develop the capability for processing the 

strong-motion records, for reproducing original and processed data, and for rapidly 

disseminating the data to cooperating organizations and agencies. 

• Contact all organizations and agencies that 

deploy strong-motion instruments and compile data on the location and characteristics 

of such instrumentation. Disseminate this 

information to any organization contemplating the installation of additional strongmotion instruments. 

• Disseminate the information on strong 

ground motion and structural response to en19 

gineering organizations concerned with 

structural-design codes and manuals. 

EARTHQUAKE INFORMATION SERVICES 

GOALS 

• Provide accurate information on the location, 

magnitude, and relevance of all earthquakes 

worldwide of magnitude 61f2 or larger and 

U.S. earthquakes of magnitude 4 or larger 

within 1-2 hours. 

• Locate as many earthquakes worldwide as 

can be accurately and rapidly determined 

with data collected cooperatively from stations throughout the world. 

• Publish research-quality earthquake hypocenters and magnitudes for the use of the 

seismological research community. 

• Collect, interpret, and publish Modified Mercalli intensity (felt) data on domestic and 

foreign earthquakes. 

• Provide a focus for public and technical inquiry for information on earthquakes, s-eismicity, and related topics. 

APPROACH 

A well-defined need exists for the notification 

of disaster-relief agencies, scientists, and the 

public when significant earthquakes occur 

within the United States. This need also exists 

when disastrous earthquakes occur in heavily 

populated regions throughout the world. The 

USGS National Earthquake Information Service (NElS) is responsible for rapidly locating 

such earthquakes and issuing notification to 

the proper authorities, scientists, and the public within 1-2 hours of the occurrence. For 

1-2 days after the occurrence of a disastrous 

earthquake, the alerting service also acts as a 

clearinghouse for information from and to the 

stricken area. 

At present the principal sources of arrival 

time and amplitude data are from an eightstation telephone network to the alerting service at NElS, and from tsunami-warning stations by teletype. Additional data can be obtained by direct teletype inquiry to a few universities in California. It is important that 

the telephone data network and the rapid university response be expanded to cover the Central and Eastern United States and overseas 

stations that fill gaps in worldwide coverage. 
The USGS Preliminary Determination of 

Epicenter.s (PDE) Program collects observations from seismic stations throughout the 

world and locates about 5,000 hypocenters annually. This i.s an international service that provides the data base for much of the research 

in seismology. The publication of the PDE 

hypocenters is accomplished within a few 

weeks of the occurrence of the earthquakes. 

Monthly summaries of hypocenter locations 

are published with a lag time of only 3 months. 

The primary needs in this program are to 

lessen the lag time for publication, to fill gaps 

in worldwide coverage, and to improve the relative and absolute accuracies of the earthquake 

hypocenters. 

The USGS also supplies a wide range of information services to the public in answer to 

direct inquiry and publishes seismicity maps, 

annual earthquake summaries, popular brochures, and list of earthquakes and station locations. 

SPECIFIC TASKS 

• Expand the telemetric network to provide 

better real-time coverage in the Central and 

Eastern United States. 

• Consolidate the US'GS se.ismic- and tsunamiwarning station services by telemetry to the 

National Earthquake Information Service. 

• Publish preliminary hypocenters on a time 

frame of a few days after the occurrence of 

earthquakes. 

• Reduce the errors in hypocenter determinations through use of better .station coverage 

and relative location techniques. 

• Lower the thresholds of detection and location for earthquakes that occur within the 

United States. 

• Incorporate improved methods of describing 

earthquake focal parameters, such as magnitude, depth, seismic moment, effective 

stress, displacement, and length of faulting. 

• Improve techniques for presenting regional 

seismicity data. 

POSTEARTHQUAKE STUDIES 

GOALS 

• Observe the causes and effects of the particular earthquake. 

20 

• Check geological and geophysical theory 

against actual behavior of the natural system. 

• Observe previously unrecorded effects that 

will guide the extension of current theories. 

APPROACH 

Postearthquake examinations depend in large 

measure on the particular set of effects that 

reveal themselves in a given earthquake. Of 

special scientific interest will be the fault that 

produced the earthquake, whether or not it 

broke the ground surface, and what the patterns and amounts of offset are. The position 

of the fault plane in three dimensions can be 

determined by analysis of P -, S-, and surfacewave data from stations recording the earthquakes throughout the world. The relationship 

of aftershock activity to the fault rupture during the main shock can be determined from 

data obtained from a network of portable seismograph stations installed as rapidly as possible after the main shock. The seismographs 

in this network should be designed to cover as 

wide a dynamic range as possible since, if the 

main shock is large, aftershocks will occur 

over a wide range of magnitudes, often very 

close to the seis,mographs. 

Landsliding and other ground failures will 

be mapped, and their relation to geologic factors analyzed. Portable strong-motion seismographs will be used to record major aftershocks 

and thus develop data on the free-field ground 

motions. Studies of strain accompanying the 

earthquake will be made by geodetic methods, 

and gravity changes will be made where appropriate. 

Effects on water, both surface and underground, will be studied. 

The period after some J.arge earthquakes is 

an especially opportune time in which to study 

jointly with engineers and planners the interrelation of Earth-science factors of earthquakes 

and human activities. The relation of ground 

motion and fault d·isplacement to damage of 

structures, for example, shoulrl be analyzed. 

Effort should be planned to accomodate the 

needs of emergency-response activities. Inventor-ies of critical facilities should be assembled 

for seis·mic regions. The rapid determination of 

the hypocenter and magnitude of major earth-
quakes by the NElS would then permit the application of theoretical isoseismal maps from 

which lists of potentially damaged facilities 

could be printed and provided to emergency 

response activities within a matter of hours. 

Data also should be provided regarding emergency water supply, least hazardous areas for 

relocation, and the likelihood and magnitude of 

aftershocks to be expected. The general public 

should be informed by the Earth scientists 

through the press, radio, and television about 

the nature of earthquakes so that it may respond intelligently and without panic. 

SPECIFIC TASKS 

• Map the causative fault by photogeologic 

and ground examination. 

• Determine the offsets along the fault and 

any evidence of past movements. 

• Determine the parameters of the fault plane 

by analysis of P- and S-waves and surface 

waves recorded at stations throughout the 

world. 

• Determine the three-dimensional position of 

the causative fault by microearthquake studies of aftershocks employing portable seismographs. In doing this, ·also determine the 

space-time-magnitude history of the aftershock sequence. 

• Determine strains in the Earth's crust by 

geodetic methods, tiltmeters, or other instrumental means. 

• Determine gravity changes. 

• Map areas of landsliding and other ground 

failures and determine the cause of instability. 

• Determine the effects on w·ater, both surface 

and underground. 

• Determine free-field ground response of different geologic units by deploying portable 

strong-motion instruments to record strong 

aftershocks. 

• For State and Federal disaster-relief agencies, develop estimates of the magnitude and 

nature of probable losses in future earthquakes. 

APPLICATION AND DEMONSTRATION PROJECTS 

GOALS 

• Develop administrative, economic, and social 

techniques by which the Earth sciences may 

21 

have direct impact on reducing the hazard 

of earthquakes. 

• Demonstrate through application the feasibility of the administrative, economic, and 

social techniques in reducing the hazard of 

earthquakes. 

APPROACH 

The hazard of earthquakes can be reduced 

through two general avenues: by proper land 

use and by proper engineering design and construction. The hazard of earthquakes can be 

modified or the risk can be spread through insurance, by proper disaster preparedness, and 

by proper d,isaster response. 

Proper land use can be developed through 

long-range plans, zoning ordinances, grading 

or building codes, and consideration of earthquake risk by insurance companies and financial institutions. Proper engineering can be 

developed through building codes and guidelines 

for the theoretical and practicing engineer. The 

USGS will collaborate with other Federal 

agencies such as the National Bureau of Standards, the States, and local communities and organizations such as the Structural Engineers 

Association of California and the International 

Association of Building Officials to develop 

model ordinances, codes, and guidelines most 

suitable in light of Earth-science factors. The 

States or local communities will be primarily 

responsible for applying the ordinances or codes 

and for evaluating their effectiveness. 

SPECIFIC TASKS 

• In collaboration with State agencies, develop 

model State legislation for earthquake hazard reduction. 

• In collaboration with State agencies, develop 

mechanisms for dissemination of guidelines 

on earthquake hazard reduction to local communities. 

• In collaboration with selected local communities, develop and test model ordinances, codes, 

and guidelines for earthquake hazard reduction. 

• In collaboration with engineers, develop improved codes and standards that will most 

suitably accommodate Earth-science factors. 

• Prepare information leaflets, booklets or 

manuals, and films for dissemination of information to the general public. 
EXTRAMURAL GRANTS AND CONTRACTS 

The Earthquake Hazard Reduction Program 

of the USGS is being implemented by utilizing 

the capabilities of the USGS and universities, 

States, and the private sector. Proposals are 

solicited through such publications as the Commerce Business Daily, Geotimes, and EeS. A 

grants review panel made up of outstanding 

non-USGS scientists assists the USGS in selecting the projects to be supported. The projects 

are judged according to: 

1. The capability of the individual scientists 

making the proposal, 

2. The capability of the scientist's institution 

to carry out a project serving the missions of the program, 

3. The appropriateness of the proposed project as it may serve, mesh with, supplement, or broaden the inhouse research of 

the USGS program, and 

4. The proposed budget for the project in balance with that of other extramural and 

inhouse project budgets and the total 

funds available. 

GEOGRAPHIC DISTRIBUTION OF EFFORT 

The geographic distribution of the proposed 

program within the next few years and the 

nature of the program in each area will be as 

follows: 

1. San Francisco Bay region.-For the San 

Francisco Bay region, a multifaceted program 

of geologic-hazard evaluation and mapping is 

underway in which the basis for predicting 

ground motion and ground failure is being d·eveloped. Techniques of predicting slope stability under seismic shaking are being developed, 

and the relative hazards of different slopes are 

being mapped. Changes in vertical elevation 

that may occur during an earthquake will be 

analyzed. Additional work will be done on fault 

mapping and evaluation. 

2. Greater Los Angeles region.-A multifaceted program of geologic-hazard evaluation 

and mapping for the greater Los Angeles region will emphasize mapping and evaluation of 

active faults and slope-stability and liquefaction studies. Priority will be given to those 

areas considered most likely for development 

in the near future. 

22 

3. Central San Andreas fault.-The central 

San Andreas fault will be a major field laboratory for intensive instrumentation aimed at 

developing predictive capabilities and fundamental understanding of tectonics. An attempt 

will be made to monitor this area fully for 

stress and strain changes. 

4. Northern and southern San Andreas 

fault.-The northern and southern San Andreas fault will be studied by selected techniques to provide an overview of the behavior 

of the San Andreas fault system. Seismic nets 

for microearthquake study will be combined 

with strain measurements and analyses of the 

tectonic style of the regions. 

5. Northwest Washington.-A disaster-relief planning study and development of a regional risk map are underway. Northwest 

Washington will be studied by a minimum deployment of seismic instruments and by a reconnaissance of geologic hazards. 

6. Central N evada.-Central Nevada has 

potential as a future test site for earthquake 

modification and control experiments. Geologic 

mapping and background studies of the seismicity, tectonics, and fault behavior will be 

carried out in se·arch of a suitable test site. In 

addition a regional risk map will be completed 

for the entire State. 

7. Rocky Mountain region.-In the Rocky 

Mountain region, the emphasis will be on an 

analysis of faulting, its distribution, and its 

mechanis.ms. For this purpose a combination 

of seismic nets and photogeologic and ground 

studies of faults will be employed. A regional 

risk map has been completed for Utah. Regional risk maps for Idaho and Montana are 

under development. A disaster-relief planning 

study for the Salt Lake area is planned. 

8. Mississipp.i Valley.-A preliminary risk 

map for the Mississippi Valley has been completed. Seismic instrumentation and geologic 

analysis aimed at defining the recurrence, 

mechanisms, and distribution of earthquakes 

of the New Madrid type will be the principal 

goals. 

9. Alaska.-The earthquake problems of 

Alaska must be approached selectively because 

of the size and complexity of the area. Attention will first be given to the region bordering 

the Gulf of Alaska and will consist of expand-
ing seismic networks and geologic and tectonic 

analysis of major faults such as the Fairweather and Denali. 

10. Eastern United States.-Although the 

seismicity and earthquake hazards are poorly 

defined for much of the Eastern United States, 

sufficient data are now available to develop 

generalized risk maps. Selected seismic networks in South Carolina, New York, and New 

England are expected to provide new data from 

which hazard investigations and risk analyses 

can be developed. 

11. Puerto Rico.-A modest effort involving deployment of a minimal seismic net is 

proposed to help define and evaluate the seismic 

hazard in Puerto Rico, particularly with reference to nuclear powerplant site selection. Active faults are to be m.apped and evaluated. 

Maps of seismic risk will be developed. 

INTERNATIONAL PROGRA.MS AND 

COOPERATION 

A rational program of earthquake hazard 

reduction cannot be based upon a limited, provincial view of a natural process that involves 

the reactions of the Earth's crust and interior 

as a whole. Some parts of the Earth's crust are 

far better suited for studying certain basic 

pHysical processes than are others. Furthermore, for the most rapid evolution of ideas and 

concepts, the program of the USGS should 

make a strong effort to keep fully abreast of, 

and participate in, the science as it develops 

in other countries. 

THE WORLDWIDE NETWORK OF STANDARD 

SEISMOGRAPHS 

One of the most important international cooperative efforts involves the Worldwide Network of Standard Seismographs (known as 

WWNSS), which was created during the 

early 1960's to enhance the coverage of seismic events with instruments that have similar response characteristics. This network 

presently consists of 29 continuously recording 

stations in the United States and 86 stations 

distributed in 68 other countries and territories throughout the world. Each station is 

equipped with north-south, east-west, and ver23 

tically oriented long- and short-period seismometers, correctable timing systems, and photographic-paper recorders. The station records 

are sent monthly to the Seismology Data Center in Asheville, N.C., where they are copied 

on 70-millimeter film and can be duplicated on 

film or paper for applied purposes and for research. The successful operation of the WWNSS 

system depends upon widespread voluntary cooperation among individuals, institutions, and 

nations. It has become the essential source of 

observational seismological data for locating 

earthquakes, determining focal mechanisms, investigating wave propagation, and developing 

concepts of global and regional tectonics. 

The WWNSS has played a vital ·part in fostering the investigations of the solid Earth 

by seis·mologists and earthquake engineers. Less 

than 1,000 epicenters per year were routinely 

located previously, whereas 5,000 or more epicenters per year are now located-mainly as a 

result of data from the WWNSS. These epicenters, when plotted on maps, provide the 

facts for delineation of plate boundaries and 

for development of seismic risk maps. Determination of earthquake focal mechanisms from 

the particle motions of P- and S-waves indicated on the WWNSS records has led to an 

improved understanding of the orientation of 

fault systems throughout the world. Wavepropagation studies with WWNSS data have 

led to the development of improved traveltime 

tables and increased greatly the understanding 

of the attenuation characteristics at the surface and in the interior of the Earth. The 

knowledge of the attenuation characteristics is 

an important contribution to the identification 

of seismic hazards and the estimation of seismic 

risk. 

The responsibility for maintenance of equipment for and supply of materials to the 

WWNSS stations was transferred from NOAA 

to the USGS in September 1973. During the 

next 5 years the USGS hopes to improve the 

output of the WWNSS by replacement of timing systems and addition of multiple-level recording capability at many of the stations. 

The Advanced Research Projects Agency of 

the U.S. Department of Defense is assisting 

some of the countries in upgrading the instrument capabilities of selected stations. 
USA-USSR COOPERATIVE PROGRAM IN 

EARTHQUAKE PREDICTION 

As a result of President Nixon's visit to 

Moscow in May 1~72, an Agreement for the 

Protection of the Environment was developed 

and placed under the overall -supervision of the 

Council on Environmental Quality. A program 

for earthquake prediction was included among 

the topics for study. 

In 1973 working groups in earthquake prediction were exchanged, and agreements were 

reached for the conduct of the first 2 years of 

the program. The agencies involved are the 

Schmidt Institute of Earth Physics for the 

USSR and the USGS, with financial assistance 

from the National Science Foundation, for the 

United States. The U.S. program, however, 

will draw in large part on the universities and 

private sector for staffing the exchange projects. 

OTHER INTERNATIONAL PROGRAMS 

An exchange with the Peoples Republic of 

China has been organized by the National 

Academy of Sciences to consider earthquake 

research. Members of the USGS will participate in this program. 

The USGS has participated in cooperative 

programs in tectonics and earthquake problems 

with Turkey, Iran, and Pakistan through the 

Central Treaty Organization as well as the 

individual countries. The North Anatolia fault 

in Turkey has been far more active in recent 

decades than the analogous San Andreas fault 

in California, thus presenting an unusual opportunity to make field experiments applicable 

to the hazards in California without depending 

entirely upon seismic events in California. 

In seismically active. New Zealand, the scientific community has developed many innovative approaches of interest to U.S. colleagues. 

Exchange of technical personnel has been 

sporadic, and a continuing exchange should be 

developed. 

Japan and the United States have maintained 

close ·communication through a series of meetings held jointly to discuss earthquake prediction. More could be done on a continuing scientific exchange. 

A long-term program of earthquake hazard 

reduction, involving USGS advisors, has been 

24 

formalized in Nicaragua with financial aid 

from the U.S. Agency for International Development. In additional studies, seismovolcanic 

activity is being monitored using satellite communication. 

The great seismic belt of western South 

America is a continuation of the western 

North American belt, and cooperative programs, which have been short in the past, 

should be enlarged with such countries as Chile, 

Peru, and Bolivia. 

The seismic belts of the ocean floor are keys 

to global tectonics and must receive continued 

major attention. Studies of the structure of 

the oceanic crust have led to a dramatic revolution in concepts of Earth science. Within the 

framework of these studies possibly lie major 

answers to the driving forces for earthquakes. 

The USGS should be involved in the Geodynamics Program being developed as an international cooperative program in the Earth sciences. 

EARTHQUAKE ENGINEERING 

"Earthquake Engineering Research," a report to the National Science Foundation prepared by the Committee on Earthquake Engineering Research, Division of Engineering, National Research Council, National Academy of 

Engineering, was published in 1969 by the National Academy of Sciences. This report elaborates the requirements of a national earthquake 

engineering research program, which need not 

be repeated here. In 1973 a report titled 

"Strong-Motion ·Engineering Seismology," prepared by the Panel on Strong-Motion Seismology of the Committee on Seismology, National 

Academy of Sciences and National Research 

Council, made recommendations for expanding 

some critical parts of the overall earthquake 

engineering effort. 

Earthquake engineering research should have 

as its objective the development of methods of 

engineering analysis, design, and practice to 

produce safe and economical earthquake countermeasures in structures. The other currently 

practical means of reducing earthquake hazards are through proper land use and through 

effective emergency preparedness and response. 

The major capability for the conduct of 

earthquake engineering has resided in the uni-
versities and private sector, although Federal 

agencies such as the National Bureau of Standards, the U.S. Army Corps of Engineers, and 

Bureau of Reclamation have made important 

studies. In addition, some State agencies have 

conducted earthquake engineering research. 

Because of the involvement of the universities, 

the National Science Foundation, in its role as 

a research-funding agency, has become the 

major Federal agency responsible for earthquake engineering research .programs. As described in the section "Seismic Engineering," 

the USGS .program includes a major effort in 

strong-motion engineering seismology with the 

financial support of the National Science Foundation. 

Other Federal agencies that require earthquake engineering data in the conduct of their 

programs have also provided- some support for 

earthquake engineering research. Among these 

agencies are the Atomic Energy Commission, 

Veterans Administration, HUD, the Department of Health, Education and Welfare, and 

the Department of Defense. The USGS program expects to continue to be responsive to 

these needs. 

LAND-USE PLANNING 

Land-use planning to serve a variety of environmental, socio-economic, and hazard reduction needs is a relatively new practice. No national land-use plan has yet been enacted, although important programs do include elements 

of land use. For example, the National Flood 

Insurance Act requires that local communities 

develop land-use ordinances and other administrative techniques for reducing flood hazards, 

but no national program yet applies to the 

reduction of earthquake hazards through landuse planning. 

The USGS, in a program financed partly by 

the Office of Research and Technology, Department of Housing and Urban Development, is 

attempting to develop guidelines for land-use 

planning related to earthquake hazards in the 

San Francisco Bay region. HUD also has financed studies to assist counties and cities to 

develop better land-us·e procedures for reducing earthquake hazards. 

In large measure, the responsibility for land 

use is at the State and local government level. 

25 

The State of California, for example, requires 

that a seismic safety element be incorporated 

in the long-range plans of communities. Also, 

statewide ordinances governing land use near 

active faults are being developed. Some cities 

--such as Los Angeles, Hayward, and Portola 

Valley in California-are in the process of developing land-use ordinances related to earthquake hazards. 

The Earthquake Hazard Reduction Program 

of the USGS, particularly the p·rogram element 

"earthquake hazard mapping and risk evaluation," is aimed at the reduction of the hazards 

through proper land use. The major users will 

be State and local governments, but their capabilities must be greatly improved and new administrative techniques related to land-use 

planning must be developed in order to reach 

the hazard reduotion goals. 

EMERGENCY PREPAREDNESS 

AND RESPONSE 

The report "Disaster Preparedness," a report 

to Congress by the Office of Emergency Preparedness in 1972, identifies major needs for 

preparedness for all natural disasters including 

earthquakes. Emergency preparedness and response constitute one of the major practical 

actions that can be taken to reduce economic 

losses, casualties, and suffering after an earthquake. 

The Federal Disaster Assistance Administration, HUD (formerly a part of the Office of 

Emergency Preparedness of the Executive Office of the President) , has the major Federal 

responsibility for emergency prepa~edness, including funding of research and major reconstruction. The Defense Civil Preparedness 

Agency of the Department of Defense shares 

some of the responsibility, and numerous other 

Federal agencies carry specialized responsibilities. For example, the Small Business Administration provides funds for reconstruction, the 

U.S. Army Corps of Engineers provides equipment and capability for search and rescue and 

reconstruction, and the Department of Health, 

Education, and Welfare is concerned with 

health problems that follow a disaster. In addi ... 

tion, most States have parallel organizations 

that are concerned with disaster response. 

The aim of the program of the USGS is to 

provide the necessary basic data for effective 
emergency preparedness, for example, an accurate scenario of what can be expected and 

where. The volume "Disaster Preparedness" 

emphasises the desirability and value of prediction and warning but recognizes that for 

earthquakes this is not currently feasible. A 

report on earthquake risk evaluation for the 

San Francisco Bay regiQn was prepared under 

the auspices of NOAA, and similar studies for 

the Los Angeles and Seattle areas begun under 

NOAA are being completed within the USGS 

program. 

ORGANIZATION OF THE GEOLOGICAL SURVEY 

Office of the Director 

Director 

Associate Director 

Senior Scientist 

I 

Chief Geographer 

Chief, Office of Information 

Earth Resources Observation 

Systems (EROS) Program 

I I 

Assistant Directors Assistant Directors 

Environmental Conservation Eastern Region 

Research Central Region 

Program Western Region 

Administration 

I I I I 

I Administrative Division I I Conservation Division I I Water Resources Division I I Topographic Division I 

I I 

I Computer Center Division I I Geologic Division J t Publications Division I 

u.s. GOVERNMENT PRINTING OFFICE: 1974-543-585/137 

26 
ORGANIZATION OF THE GEOLOGIC DIVISION 

Office of the Chief Geologist 

Chief Geologist 

Deputy Chief Geologist l 

Deputy Chief Geologist for Regional Geologist, Western Region 

I Office of Scientific Publications j Program and Budget Regional Geologist, Central Region 

Administrative Officer Regional Geologist, Eastern Region 

I I l 

Office of Geochemistry Office of Office of Office of 

and Geophysics Environmental Geology Mineral Resources Energy Resources 

I I 

Office of International Geology j [ Office of Earthquake Studies J l Office of Marine Geology j 

ORGANIZATION OF THE OFFICE OF EARTHQUAKE STUDIES 

Office of Earthquake Studies 

Chief (Reston, VA) 

Deputy for Engineering (Reston, VA) 

Deputy for Geology (Reston, VA) 

Deputy for Seismology (Reston, VA) 

Staff Geophysicist (Menlo Park, CA) 

Chief Scientist (Menlo Park, CA) 

Manager of Grants and Contracts (Menlo Park, CA) 

l 

I I I I 

Branch of Seismology Branch of Earthquake Tectonics Branch of Seismicity Branch of Seismic Engineering 

(Menlo Park, CA) (Menlo Park, CA) and Risk Analysis (San Francisco, CA) 

(Boulder, CO)