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no. 116:/ 


partment of Wa ter Resources 

BULLETIN No. 116-1 





Progress Report 

MAY 1963 







The Resources Agency of California 

State of California 

Department of Water Resources 


































Active Earthquake Faults in California 

state ot Calitornia 

Department of Wa ter Resources 

BULLETIN No. 116-1 




Progress Report 

MAY 1963 


Administrator Governor Director 

The Resources Agency of California State of California Department of Water Resources 

u*i».raii;iTY OF CALlFOHAiA 









United States Coast and Geodetic Survey 12 

California Institute of Technology 12 

University of California at Berkeley 13 

Stanford Research Institute 13 

Other Universities and Public Agencies 13 

Earthquake Engineering Research Institute 14 


Scope and Objectives of Investigation 15 

Program Accomplishments to Date l8 

Fault and Earthquake Epicenter Map l8 

Earthquake Hazard Evaluations 19 

Electronic Data Processing 19 

Technical Reports 20 

Geodlmeter Survey 20 

Trlangulatlon Survey 21 

Federal-State Cooperative Subsidence Leveling 

Program 22 

Future Program 22 

Applied Seismology Studies 23 


Geodetic Studies 30 

Engineering Geology Studies 32 


Illustration No , 





Active Earthquake Faults in California 
San Andreas Fault, San Bernardino County 
San Andreas Fault, San Luis Obispo County 


Plate No. 

(Plates bound at end of bulletin) 

1 Crustal Strain and Fault Movement Investigation 
Geodetic Program 


'jputy Director 

iDireclor Policy 






P. O. Box 388 
Socramenlo 2, Colif. 




February 27, I963 

The Honorable Edmund G. Brown, Governor, and 
Members of the Legislature of the 
State of California 


I have the honor to transmit herewith Bulletin No. II6-I, 
"Crustal Strain and Fault Movement Investigation — Progress Report." 
This Investigation was initiated by the department in 1959 under 
funds budgeted for the California Water Development Program. Plans 
are under way to implement additional Investigations into earthquake 
problems and their solution based on recommendations of our Consult- 
ing Board for Earthquake Analysis. 

The major objectives of the department's earthquake engin- 
eering investigations are: (l) to Investigate, evaluate, and report 
on all phenomena of earthquakes, faults, and crustal movements which 
may affect engineering planning, design, construction, operation, and 
safety of hydraulic structures; and (2) to develop earthquake, crus- 
tal movement, and aseismic design factors and criteria to improve or 
replace the empirical factors in current use for the engineering 
design of hydraulic structures in California, 

Bulletin No. II6-I has been prepared primarily as a brief 
report to the Legislature on the objectives, accomplishments, and 
proposed future program of the Crustal Strain and Fault Movement 
Investigation -- which may appropriately be referred to as the earth- 
quake hazard studies of the department. This report also briefly 
refers to the objectives of the programs now being formulated for the 
department's other earthquake engineering investigations. This 
report will provide background for a series of earthquake data and 
earthquake engineering reports which will be issued by the department 
as progress is made in these investigations. 

Sincerely yours. 






EDMUND G. BROWN, Governor 
HUGO PISHER, Administrator, The Resources Agency of California 
WILLIAM E. WARNE, Director, Department of Water Resources 
ALFRED R, GOLZE ' , Chief Engineer 


William L. Berry Division Engineer 

Raymond C. Rlchter Geology Staff Specialist 

The investigation leading to this 
report was conducted under the direction 


Meyer Kramsky* Chief, Statewide Investigations Branch 

Carleton E. Plumb Chief, Planning Investigations Section 


David M. Hill Senior Engineering Geologist 

William M, Gibson Associate Engineer, Water Resources 

Laurence B, James Chief Geologist and Coordinator of 

Department's Seismic Investigations 

*Albert J. Dolclnl was Chief of the Statewide Investigations Branch 
until July 1, I962. 



Valuable assistance^ data, and consultation by federal, 
state, and private agencies and Individuals have materially assisted 
the department in its studies of seismic problems in California. In 
particular, the continued cooperation and assistance of the following 
individuals and agencies are acknowledged: Professors Hugo Benioff, 
Charles Richter, George Housner, and Clarence Allen, California In- 
stitute of Technology] Professors Perry Byerly and Donald Tocher, 
University of California at Berkeley; Dr. Pierre St. Amand, China 
Lake Naval Ordnance Test Station; the United States Coast and Geo- 
detic Surveyj the United States Geological Survey; and the California 
State Division of Mines and Geology. 

Additional guidance in formulating departmental earthquake 
engineering investigations and in developing rational factors for 
earthquake-resistant design of hydraulic structures will be provided 
by the recently constituted Consulting Board for Earthquake Analysis. 
Dr. Hugo Benioff, Seismologist, California Institute of Technology, 
specializing in seismic phenomena and instrumentation, is chairman of 
the board. Members of the board include: Dr. George W. Housner, a 
Structural Engineer, California Institute of Technology, specializing 
in engineering seismology and earthquake-resistant design; Dr. Harry B. 
Seed, Soils Mechanics, University of California at Berkeley, special- 
izing in soil mechanics and model studies in connection with earth 
dams; Mr. Nate D. Whitman, Jr., Consulting Engineer, specializing in 
design of hydraulic structures; and Dr. James L, Sherard, Consulting 
Engineer, specializing in the design of embankment dams. 



Bulletin No. II6-I has been prepared as a brief report to 
the Legislature on the objectives, present accomplishments, and pro- 
posed program of the department's Crustal Strain and Fault Movement 
Investigation in the Division of Resources Planning. This activity 
is a part of the department's overall program of earthquake investi- 
gations. Specialized technical model and earthquake design studies, 
which are conducted by the Division of Design and Construction and 
' the Supervision of Dam Safety Office, are only briefly mentioned 
herein. The data collected by the Crustal Strain Unit are utilized 
by the Division of Design and Construction in their program for 
developing earthquake design criteria for the State Water Facilities. 
These data are also of value to the Supervision of Dam Safety Office, 
the Division of Operations, and the planning activities of the 

This bulletin is the first of a series of reports which 
will present the results of the various technical earthquake and 
crustal movement studies being conducted in the Division of Resources 
Planning. The first basic data report in the series will be Bulletin 
No. 116-2, "Earthquake Epicenters and Faults in California," 

The Crustal Strain and Fault Movement Investigation was 
Initiated by the department in January 1959. Funds for the Crustal 
Strain Program are provided in the I962-63 budget, page 679, line 8. 


The California Water Plan envisions a system of reservoirs, 
aqueducts, pumping plants, and. other hydraulic facilities throughout 
the State. The potential threat to these structures posed by earth- 
quakes and crustal movements is an important factor in the location, 
design, construction, and operation of the various facilities of such 
an extensive project. Inasmuch as precautionary aseismic design 
measures entail additional expense, any appraisal of earthquake risk 
must also include consideration of the purpose, type, and useful life 
of the structure concerned, and the seriousness of the loss or the 
danger to life should structural failure occur. The Department of 
Water Resources has undertaken the Crustal Strain and Fault Movement 
and other earthquake engineering Investigations herein described, to 
provide objective evaluations of the potential hazards related to our 
sporadic earthquakes, and to provide rational criteria for the design 
of hydrauic structures to obviate or minimize any adverse effects 
from future earthquakes. 

Evaluation of earthquake activity indicates that California 
is located in the second most highly seismic area in the United 
States, the first being Alaska. The great majority of reported 
earthquakes in California are associated with major fault systems 
concentrated in the Coast Ranges in Central and Northern California, 
in the Transverse and Peninsular Ranges in Southern California, and 
in the Sierra Nevada. Locations of some of the known active faults 
are shown diagrammatically on the Frontispiece and in Illustrations 
1 and 2. 


Illustration 1 shows an aerial view southeastward along 
the San Andreas fault north of San Bernardino near the proposed 
Devil's Canyon Powerplant No. 2. The earthquake of January 9, I857, 
which was comparable In strength to the famous I906 San Francisco 
earthquake, accompanied rupture and displacement of the ground along 
the fault line In the area shown In the picture. The rupture ex- 
tended northwesterly from San Bernardino about I50 miles or more, 
following the trace of the fault through Antelope Valley, the moun 
tains south of the San Joaquin Valley, and Carrlzo Plain. 

Illustration 2 shows an aerial view of the San Andreas 
fault near Carrlzo Plain, which Is located about 18 miles west and 
northwest of Taft and is about I50 miles northwest of the area shown 
in Illustration 1. The abrupt offsets of stream channels at the 
fault line provide evidence of recent lateral fault movement. The 
photo is typical of an area that will be crossed by the California 

Effects of earthquakes which may damage hydraulic struc- 
tures include: shaking of foundations, surface rupture, earth 

lurches, slumps, raudflows, landslides, avalanches, seiches, and 
seismic sea waves. Any one or a combination of these effects, if 
not properly considered in design, could seriously Impair the use- 
fulness of hydraulic structures. Crustal strain in the form of 
tilting of the land surface occurs along some faults, and could 
alter the hydraulic gradient of a canal or place a critical pumping 
plant facility out of alignment without an actual earthquake. Never 
theless, experience has shown that with proper evaluation of these 

Illustration 1. San Andreas Fault , San Bernardino County (looking 
boutheast). The San Andreas fault (indicated by arrows) forms the 
boundary between the San Bernardino mountains on the left and the 
alluvlum-f llled valley on the right. 



*-vN^*c3:-* -> '; 

Illustration 2. San Andreas Fault , San Luis Obispo County (looking 
east across fault) . The California Aqueduct will cross the San 
Andreas fault in areas similar to the road crossing shown in the 
center of the photograph. The fault is indicated by arrows. 

factors Incorporated In design of hydraulic structures, these poten- 
tial problems can be minimized. 

Although California Is an area of high seismic activity, 
a preliminary review of available data on hydraulic structures In 
California Indicates that relatively few structures have been dam- 
aged by earthquakes during the past 70 years. During this period, 
l4 earthquakes caused some damage to 10 dams, 3 small water supply 
reservoirs, 1 sewage treatment plant, 1 pumping plant, and 1 power- 
plant. For example. In 19'^0 the All-Amerlcan Canal was displaced 
14 feet 10 Inches by movement along the Imperial fault Just prior 
to Initial use. Repairs were Immediately Implemented, and the canal 
was then placed In operation. During the I906 San Andreas earth- 
quake, displacements of 5 to 8 feet were measured In fills and out- 
let tunnels of three earthflll dams In the Crystal Springs area 
south of San Francisco where they were cut by the San Andreas fault. 
It should be noted that these dams did not fall. Shaking of the 
foundation and materials In Sheffield Dam (earthflll) in Santa 
Barbara County during the 1925 earthquake caused failure of the 
structure. The dam was rebuilt during the same year. 

Reports of earthquake damage to hydraulic and other engin- 
eering structures may be unintentionally misleading as to the extent 
of the damage, because emphasis may be placed on the instances of 
damage rather than on the number of structures which survive earth- 
quakes unscathed. However, the past record of hydraulic structures 
damaged by earthquakes is a reminder that damaging earthquakes have 
occurred repeatedly in the past and can be expected to recur in the 


future. Therefore, planning, design, construction, and operation oi 
the State Water Facilities must take into account all phases and 
ramifications of earthquake phenomena to minimize the potential 
damage from future earthquakes and to assure the safety of the 



Even though the historical record of California earthquakes 
extends back to 1769, It was not until I887 that systematic compila- 
tion and publication of earthquake descriptions were Inaugurated. 
This valuable program was undertaken by the University of California. 
The first seismographs In California were Installed during the late 
1880 's and early l890's at the following San Francisco Bay area 
locations: Lick Observatory on Mt. Hamilton] University of Califor- 
nia (Berkeley) j Chabot Observatory (Oakland); Mills Seminary (Oak- 
land); and University of the Pacific (San Jose). Lick Observatory 
began Its active work In I888 and was the early leader In collecting 
reports of earthquakes on the Pacific Coast. 

Following the destructive San Andreas earthquake and fire 
which devastated San Francisco In I906, a State Earthquake Investi- 
gation Commission was formed to study all aspects of the earthquake 
and the resultant damage. Funds for operation of the commission and 
publication of Its findings were provided by the Carnegie Institu- 
tion of Washington, D, C, Soon after the earthquake, the United 
States Coast and Geodetic Survey remeasured Its trlangulatlon net 
In the area to determine the width of the zone affected by crustal 

After publication of the report of the Earthquake Investi- 
gation Commission, public "earthquake psychology" developed which 
opposed discussion or investigation of earthquakes, because it was 
"bad for business." In the midst of this opposition, a group of 


San Francisco Bay area geologists and others organized the Selsmo- 
loglcal Society of America. Bulletins of that society have been 
Issued quarterly since 19II. Funds to support earthquake Investiga- 
tions in California came from outside the State during those lean 
years -- largely from the Carnegie Institution of Washington. In 
1921 the Carnegie Institution of Washington established a program 
for earthquake recording and research, with headquarters in Pasadena 
The torsion seismometer was developed for this work by J. A. Anderson 
and H, 0, Wood, By the summer of 1927, four seismograph stations had 
been installed in Southern California, 

The damaging offshore submarine earthquake which struck 
Santa Barbara in 1925 reawakened public Interest in earthquake inveS' 
tlgations. As a result, new equipment was installed at the Universi 
of California at Berkeley and at Lick Observatory. New stations wer 
established at Stanford University and in San Francisco. In I925, 
the United States Coast and Geodetic Survey began publishing descrip 
tive notes of earthquakes which had formerly been published by the 
United States Weather Bureau and Lick Observatory. Most of the earl 
earthquake Investigations followed the lines of "pure science" 
because of lack of public interest and funds for applied research. 

In 1930, Stanford University and the United States Coast 
and Geodetic Survey designed and built a large shaking table for 
model studies. Even though the studies were useful in measuring the 
effects of earthquakes on structures, the work was hampered by lack 
of adequate funds, and subsequently was discontinued. About the 
same time, the United States Coast and Geodetic Survey began making 


periodic geodetic measurements along and across the San Andreas fault 
at a few critical localities with a view to accurately determining 
the rate and direction of earth movements. Surveys across the fault 
from Monterey to Pacheco Pass were made In 1930 and continued In 1932 
In the area from San Luis Obispo to Lost Hills, and from San Fernando 
to Bakersfleld. Other projects followed In subsequent years and are 
being repeated at 10-year Intervals, supported by federal funds. 

In 1932, the United States Coast and Geodetic Survey de- 
signed and put Into operation a program for the Instrumental record- 
ing of strong-motion earthquakes. Prior to that time, no appreciable 
Instrumental data had been obtainable near earthquake epicenters 
because the Initial shock always put sensitive seismographs out of 
order. This Important development enabled the recording of earth- 
quake data near the epicenters. The strong-motion seismographs have 
been placed In strategic locations like "mousetraps" to lie In wait 
for a strong shock. Unlike other sensitive Instruments, these strong- 
motion Instruments are triggered Into operation by the Initial shock. 
There are approximately 80 strong-motion seismographs located In the 
State of California, centered largely In the metropolitan areas. 

The California Institute of Technology has administered a 
selsmologlcal program for Southern California since 1937- The Uni- 
versity of California at Berkeley administers a similar selsmologlcal 
program for Northern California. The United States Coast and Geo- 
detic Survey has a separate statewide program. There Is a free and 
Informal exchange of data between the organizations that Includes 
copies of all seismograph records. As of 1956, the California 


Institute of Technology had l6 stations In operation, the Universits 
of California had 11 stations, and the United States Coast and Geo- 
detic Survey had one teleselsmlc station and about 80 strong-motion 
stations. The universities are currently adding to their networks, 

Activities of various organizations engaged in seismologic 
investigations may be generally summarized as follows: 

United States Coast and Geodetic Survey 

1. Collection and publication of descriptive Information 
on earthquakes. 

2. Compilation of earthquake history. 

3. Preparation and distribution of intensity maps of 
strong earthquakes. 

4. Operation of a network of strong-motion instruments 
located primarily in metropolitan areas and at the sites of United 
States Bureau of Reclamation dams. 

5. Detennlnation of the natural frequency of vibration 
of buildings and other structures. 

6. Location of epicenters of the larger earthquakes. 

7. Precise measurements across earthquake faults by 
means of trlangulatlon, traverse, leveling, and astronomic azimuths, 

8. Cooperation with universities and other agencies in 
earthquake engineering investigations. 

California Institute of Technology 

1. Operation of a seismological laboratory. 

2. Collection and publication of instrumental data on 
earthquakes in Southern California. 


3. Compilation and study of earthquake history. 

4. Operation of a network of seismographs. 

5. Research In all problems related to earthquakes. 

University of California at Berkeley 

1, Operation of a selsmologlcal laboratory. 

2, Collection and publication of Instrumental data on 
earthquakes In Northern California. 

3, Compilation and study of earthquake history, 

4, Operation of a network of seismographs. 

5, Research In all problems relating to earthquakes. 

Stanford Research Institute 

Instrumental recording of small shocks, determination of 
epicenters, and other research activities. 

Other Universities and Public Agencies 

Activities by universities comprise essentially the 
operation of a few seismographs and cooperation in epicenter and 
intensity determinations. In addition, the California Department 
of Public Works, Division of Architecture, in connection with its 
administration of the Field Act, has spent approximately $200,000 
in research on framed structures, and currently budgets as much as 
$50,000 annually for this purpose. Other countries, notably Japan, 
have contributed greatly to earthquake engineering research as ap- 
plied to framed structures. 


Earthquake Engineering Research Institute 

The United States Coast and Geodetic Survey, In 19^7, es- 
tablished an Advisory Committee on Engineering Seismology to assist 
the survey In Its selsmologlcal program. In 19^9^ the committee was 
Incorporated with the title "Earthquake Engineering Research Insti- 
tute." Its major purpose Is to function as an Independent Institu- 
tion to promote continuing research In engineering seismology that 
would lead to greater understanding of destructive earthquakes and 
to Improvement In safety, and In the economical design, construction^ 
and location of structures of all types to resist forces Induced by 
earth motion. 

Activities of the Institute center largely on sponsoring 
and/or promoting research and development by the Institute and 
others, mainly In the field of framed structures, to which a consld 
erable amount of research and study has been devoted. To date, 
little emphasis by 'KERl has been placed on earthquake problems re- 
lating to dams, canals, and other hydraulic structures. 



To achieve the most economic location and design of the 
various proposed State Water Facilities commensurate with safety and 
with an uninterrupted water supply, the Department of Water Resources 
has undertaken an Investigation Into the nature and extent of the 
potential problems which relate to earthquakes and crustal movements 
In California, The various technical studies Involved In the depart- 
ment's overall program of earthquake engineering Investigations have 
been grouped Into two functional categories. The Crustal Strain and 
Fault Movement Investigation comprises the first group of studies. 
These largely Involve geology, seismology, and geodesy, and are aimed 
toward obtaining knowledge of the seismic effects to be expected at 
specific sites or within specified areas. The second group of stud- 
ies Is more closely associated with structural and soils engineering 
and is Intended to develop procedures for aselsmlc design and opera- 
tion of hydraulic structures and for the Investigation of safety of 
dams. Studies In the second group are within the responsibilities 
of the Division of Design and Construction and the Supervision of 
Dam Safety Office. 

The Crustal Strain and Fault Movement Investigation was 
Initiated by the department In January 1959* following Its endorse- 
ment by Dr. Hugo Benloff, the department's chief selsmologlcal 

Scope and Objectives of Investigation 

The earthquake data and earthquake hazard studies Included 

In the Crustal Strain and Fault Movement Investigation In the Division 


of Resources Planning have the following objectives: 

1. To Investigate, evaluate, and report on all phenomen 
of earthquakes, faults, and crustal movements which may affect en^ 
gineering planning, design, construction, safety, and operation of 
hydraulic facilities built by the department. 

2. To develop rational seismic and crustal movement fac 
tors which may be utilized in engineering design, based on frequer 
and intensity of earthquakes, foundation conditions, probable crus 
displacement, and associated considerations at each site as relate 
to structural type and seriousness of loss, should structural dama 

Intrinsic in the overall objectives are the following 
specific objectives: 

1. To determine the rate, constancy, and magnitude of 
ground movements (accumulating crustal strain) near sites proposed 
for hydraulic structures. 

2. To locate active faults which may produce destructiv 
earthquakes or along which the ground surface may rupture as the 
result of accumulated crustal strain. 

3. To estimate the destructive potential of the probabl 
earthquake forces which should be anticipated at the site of each 
structure constructed on or near active faults and on foundations 
which vary in strength and stability. 

4. To estimate the amount and direction of displacement 
across active faults which may occur either abruptly or gradually 
and which may sever or otherwise damage tunnels, conduits, or othe 


hydraulic structures, or Impede the movement of water by altering 
the hydraulic gradient. 

5. To locate areas of active tectonic uplift or subsidence 
and to estimate the rate at which the resultant crustal tilting will 
alter the hydraulic gradient of canals and thus change their capacity. 

6. To develop and/or acquire and operate special instru- 
ments and equipment of various types, which will implement the fore- 
going. Such instruments are necessary in order to: (a) detect and 
measure horizontal and vertical movements of the earth's crust j 

(b) detect and record the crustal vibrations which may precede earth- 
quakes and/or surface rupture j (c) measure and record the effects of 
earthquakes on foundation materials at sites proposed for State Water 
Facilities; and (d) measure and record the effects of earthquakes on 
existing and proposed hydraulic structures. 

7. To collect and compile basic data pertaining to earth- 
quakes. Including epicentral locations, magnitude, ground vibration 
frequencies, and earthquake effects on ground surface and on manmade 

8. To prepare programs for electronic data machine proc- 
essing, analysis, and plotting of data which will facilitate the 
evaluation of earthquake and crustal movement factors. 

9. To develop rational ground motion factors and criteria 
which may be utilized in developing earthquake-resistant design of 

'hydraulic structures. 

10. To investigate the characteristics of, and potential 
foi^ earthquake-generated seiches in reservoirs and aqueducts. 


Program Accomplishments to Date 

The following are the principal activities and accompllsl: 
ments to date of the department's Crustal Strain and Fault Movement 

Fault and Earthquake Epicenter Map . A fault and earthqu 
epicenter map of the entire State, the first of Its kind, has been 
prepared and will be published shortly In Bulletin No. 116-2. Epl 
centers of all earthquakes of Rlchter Magnitude 4 and above, which 
have occurred In California and adjacent areas since 1932, are plot 
ted on the map. The map graphically represents the relative sels- 
mlclty of the various regions of the State during the past 30 years 
and will greatly assist engineers, particularly those who design hy? 
draullc structures and other types of engineering structures. In 
appraising the earthquake hazard at various locations. Over 2,000 
epicenters are plotted on the map, which shows groupings of eplcen^ 
ters In certain areas. Indicating potentially dangerous seismic 

The same map shows the most complete delineation ever pub 
llshed of faults throughout the State. The location of over 3,000 
faults Is shown. The mapped faults represent a compilation of the 
latest available geologic mapping, published and unpublished, by th 
Department of Water Resources, the California State Division of Min^ 
and Geology, the United States Geological Survey, by other state an 
federal agencies, and by other organizations and Individuals. The 
information on fault locations on this map will be invaluable in 
planning the location of hydraulic and other structures. 


The combination fault and epicenter map Is expected to 
serve as a primary reference for applied seismology throughout the 

Earthquake Hazard Evaluations . Preliminary evaluations of 
earthquake hazards at many of the sites of proposed hydraulic struc- 
tures have been completed or are under way. Such studies include: 
compilation of the earthquake history of the area, plotting of earth- 
quake epicenters In the vicinity, analysis of the magnitude and In- 
tensity of each earthquake, and evaluation of site foundation for 
stability and susceptibility to shaking. Earthquake frequency. In- 
tensity, and acceleration factors are estimated for each site to 
provide design engineers with a basis for aselsmlc design of hydrau- 
lic structures. These studies also Include consideration of some of 
the side effects of earthquakes which can cause damage, such as sur- 
face rupture, slumps, landslides, earth or mud flows, seismic sea 
waves, and waves generated within reservoir areas. 

Electronic Data Processing , A new method of tabulating 
earthquake data has been developed which utilizes electronic data 
processing equipment. The latitude and longitude, date, time, ac- 
curacy of epicenter plot, and magnitude of earthquakes occurring from 
1932 through i960 have been placed on IBM cards. A tabulation of the 
earthquake data is Included in Bulletin No. 116-2. 

Until now such data were not available for the entire State 
in the files of a single agency, but were scattered in the files of 
various agencies which have collected and analyzed them for specific 
areas and purposes. It is now possible to obtain and reproduce the 


earthquake record of any area accurately and rapidly. Utilization 
of the data processing machines will permit machine plotting of epi' 
centers on maps and enable the compilation and plotting of accumula^ 
tive earthquake energy release for any desired area. 

Technical Reports . An annotated bibliography on engineer' 
ing seismology as applied to hydraulic structures and on earthquake 
damage to hydraulic structures is being prepared. Selected technical 
reports are summarized in sufficient detail to provide essential dat| 
as well as descriptions of instrumentation and procedures. In addi-t 
tion to providing the results of the investigations and research coni 
ducted by other agencies, such a bibliography will provide a basis 
for determining which lines of investigation should be pursued fur- 
ther to satisfy the department's requirements in connection with the, 
planning, design, and operation of hydraulic structures. 

Geodlmeter Survey . Through the use of a geodimeter which 
may be generally described as the most precise distance-measuring 
device available, 65 lines crossing nine faults between San Prancisc 
and Indio have been established. The locations of these lines are 
shown on Plate 1, titled "Crustal Strain and Fault Movement Investi 
gation Geodetic Program." The purpose of these geodetic studies is 
to measure horizontal movements of the earth's crust due to strain 
build-up or fault slippage near the location of present and proposed 
hydraulic structures, to delimit areas or zones thus affected, and 
to detect strain build-up that may be released by large earthquake- 
producing fault displacements. The geodimeter lines are remeasured 
to determine the rate, direction, and constancy of differential horl 
zontal movements of the crust on opposite sides of the fault. 


Emphasis has been on measurements across the San Andreas fault; most 
of the other faults crossed are related parallel faults. Most of the 
geodlmeter lines have been surveyed three times, representing approxi- 
mately 2,600 miles of surveying over a period of three years. It 
should be pointed out that the data accumulated during this brief 
period are Insufficient to warrant positive conclusions. However, a 
preliminary evaluation of measurements across the San Andreas fault 
suggests right lateral movement (the west side moving northward rela- 
tive to the east side) between Holllster and Slmmler. The few re- 
peat measurements available between Slmmler and the Intersection of 
the San Andreas and Qarlock faults suggest left lateral movement. 
South of the Garlock fault. It has not been possible to establish a 
consistent pattern of movement. Repetition of the measurements will, 
of course, be continued to confirm or revise these preliminary evalu- 
ations, and to establish more definite directions, amounts, and, pos- 
sibly, variations of magnitude In the movements. 

Trlangulatlon Survey . Through the cooperation of the 
United States Coast and Geodetic Survey, an extremely precise trl- 
angulatlon network has been established covering the area of the San 
Andreas, Garlock, White Wolf, and other faults which converge near 
the extreme southern end of the San Joaquin Valley. The trlangula- 
tlon network Is shown on Plate 1. Repetition of the trlangulatlon 
will be accomplished after the geodlmeter measurements, previously 
described. Indicate that sufficient ground movement has taken place 
to warrant the re survey. 


Federal-State Cooperative Subsidence Leveling Program !| 

The cooperative leveling program for the measurement of 

deep subsidence has been sponsored by the department for a number ci 

years to obtain precise data on changes In elevation of the land s{\ 

face In several areas of the State. The current program Is dlrecte; 

toward obtaining such data In those areas of the San Joaquin Vallejj 

and the Sacramento-San Joaquin Delta which are critical to the desj 
and operation of the presently authorized State Water Facilities. 
The program Is administered by the Crustal Strain Unit In the Dlvls 
of Resources Planning, Funds for the cooperative program are pro- 
vided In the 1962-63 budget on page 678^ line 40. 

The principal cause of deep subsidence In the San Joaquir: 
Valley Is attributed to withdrawal of ground water. Vertical tec- 
tonic movement also Is thought to be a contributing factor In land j 
subsidence In some areas such as at the south end of the San Joaqulj 
Valley near the base of Wheeler Ridge. In either case, the potent 
adverse effect on aqueduct gradients locally will be the same as t. 
discussed under tectonic movement as measured by tlltmeters. It Is 
critical for the department to know the varying rates of land sub- 
sidence along the aqueduct route so that allowances for this factor 
may be made during design and construction of the facilities to mln 
mlze the adjustments which may become necessary after the facllltle 
are placed In operation. 

Future Program 

The department's seismic Investigations, as recommended b 
the Consulting Board for Earthquake Analysis, Include continuation 


of the foregoing activities of the Crustal Strain and Fault Movement 
Program and Implementation of additional studies employing Instru- 
mentation and engineering models. The solution to earthquake engin- 
eering problems requires an Integrated program of studies in the 
following fields: applied seismology, geodesy, engineering geology, 
and aselsmic engineering design. These studies comprise the major 
phases of the department's future investigational programs. 

As mentioned earlier, all of the department's present and 
proposed studies have been grouped into two functional categories. 
Studies which fall in the first category and which have been assigned 
to the Crustal Strain and Fault Movement Investigation in the Division 
of Resources Planning are discussed under the following headings: 
Applied Seismology Studies, Geodetic Studies, and Engineering Geology 
Studies. Studies which have been assigned to the second category and 
which are the responsibility of the Division of Design and Construc- 
tion and the Supervision of Dam Safety Office, are presented in the 
next chapter under the heading. Departmental Earthquake Engineering 

Applied Seismology Studies . Studies of the phenomena 
associated with earthquakes, and the behavior of foundation materials 
and hydraulic structures during earthquakes, comprise the keystone in 
establishing aselsmic design criteria. The following seismological 
studies are part of the future program in the Crustal Strain 

1. Seismological field studies involving various types 
of seismic instrumentation will be a major effort of the dopartment ' s 


program in securing Information on ground, motion characteristics. 
The following field instrumentation program is under way or in the 
final planning stages: 

a. Installation and operation of a series of 
strong-motion seismograph assemblies includ- 
ing accelerometers and. displacement meters, 
and supporting seismoscopes. These instru- 
ments will be established in critical areas 
throughout the State and maintained for an 
approximate 10-year period or longer. In 
the event of a large earthquake, these in- 
struments will provide valuable design data 
which cannot be secured from the sensitive 
instruments. In most major earthquakes , 
sensitive instruments are commonly rendered 

b. Installation and operation of portable high- 
sensitivity seismographs for use in deter- 
mining the ground spectral amplification 
factor for critical sites and for determin- 
ing the spectral response characteristics 

of selected existing dams. Two high- 
sensitivity seismographs will be acquired 
and used at individual structure sites. 
Where such sites are underlain by alluvium 
or by slightly to moderately compacted 


sediments, one seismograph will be located 
on the proposed site, and a second Instru- 
ment will be located on rock in the near 
vicinity of the site. Frequency curves 
for design use can be compiled by digitiz- 
ing records from the two seismographs. 
Maintenance of these instruments at a pro- 
posed site during several smaller earth- 
quakes will provide adequate data for 
design, thus allowing seismographs to be 
moved to other structure sites. 
Installation and operation of a fused- 
quartz strain extensometer at the recently 
acquired site in Antelope Valley, Los 
Angeles County, about l4 miles southeast 
of Gorman. This instrument will provide 
a record of the accumulation of strain in 
bedrock in the wedge-shaped crustal block 
between the San Andreas and Garlock faults. 
Earthquakes and surface rupture are the 
predicted effects which will occur when 
the accumulating strain is suddenly re- 
leased. It will also record the transient 
strains induced in bedrock during the 
passage of earthquake waves. 
Installation and operation of tripartite 
tiltmeters to determine the direction and 

rate of tilt along the alignment of aque- 
duct routes and at other critical locations 
such as pumping plant sites. Tlltmeters 
will be located in tectonlcally active areas, 
and measurements repeated at periodic inter- 
vals, in order to evaluate the extent and 
the magnitude of the problem. 
Installation and operation of permanent 
seismograph stations associated with State 
Water Facilities* A class A seismograph 
station is presently under construction at 
Oroville Dam, Butte County. This station 
will provide a continuous record of earth- 
quake activity in the Oroville and adjacent 
areas with respect to the dam and appurte- 
nant structures. Data from this station ivill 
be useful in establishing seismic design 
criteria for projects contemplated under the 
State Water Resources Development System. 
Installation and operation of the recently 
acquired variable reluctance transducer seis- 
mograph on the San Andreas fault or in an 
area of the State, such as the North Coastal 
area, where seismograph records are insuf- 
ficient or are not available. A sensitive 
seismograph station at such a site (l) will 


monitor some of the local "rock noises" 
or microtremors generated by nearby active 
faults which may be the precursor of a 
major earthquake, (2) will assist in deter- 
mining epicentral locations of all earth- 
quakes in the area, and (3) will furnish 
data on ground motion characteristics at 
the site. 
2. Selsmological office studies will be undertaken as 
needed in order to evaluate seismic hazards at proposed structure 
sites. Studies undertaken may include, but not necessarily be 
limited to, the following: 

a. Continuing collection and processing of 
basic data on earthquakes. Including their 
effects on ground surface and on manmade 
structures, and programming the earthquake 
data for machine analysis. Coordination 
with universities and the Coast and Geo- 
detic Survey will be continued to obtain 
all available seismological data pertinent 
to the program, 

b. Development of special types of earthquake 
data maps in the future at critical struc- 
ture sites or areas. The preparation of 
these special maps depicting magnitude, 
intensity, and acceleration, and the analy- 
sis of their correlation and interrelationship 


with the phenomena and. expression of strain 
energy release, are steps in the development 
of rational factors for earthquake-resistant 
engineering design of State Water Facilities, 
Some of the special maps which might be 
compiled Include: 

(1) Maps depicting eplcentral locations 
of earthquakes below Rlchter Magni- 
tude 4, These small earthquakes 
are the result of minor adjustments 
in the earth's crust. Such earth- 
quakes release a small, but appre- 
ciable, portion of the elastic 
strain energy which accumulates 
in the earth's crust as the result 
of crustal movements. Thses smal^l 
earthquakes also reflect adjust- 
ments in the crust which are the 
consequence of the rapid release 
of accumulated strain energy dur- 
ing major earthquakes. The pat- 
tern which develops by plotting 
the epicenters of small earth- 
quakes may provide a clue to the 
mechanism involved in the strain 
build-up which results in major 

earthquakes . 


(2) Earthquake intensity maps depleting 
areas In which earthquake damage has 
been reported or which have been 
subjected to moderate to Intense 
shaking. Such a map may be useful 
In developing rapld^ qualitative 
appraisals of the earthquake hazards 
at sites of proposed facilities of 
the State Water Resources Develop- 
ment System. 

(3) Maps depleting cumulative earthquake 
energy release. The map would show 
graphically whether strain energy Is 
being released by numerous minor 
earthquakes along some faults or 
segments of faults or by only a few 
major earthquakes along other faults 
or fault segments. Thus, the rela- 
tive seismic activity of a proposed 
site could be compared with adjacent 
areas. This map will assist In plan- 
ning the location and design of hy- 
draulic structures by providing a 
numerical basis for appraising the 
earthquake hazard In any area In 
terms of the rate at which earth- 
quake energy Is released. 


3. The Consulting Board for Earthquake Analysis has recc 
mended that the department undertake a study of long-period standlr 
waves (seiches) which may be generated In reservoirs as a result of 
earthquake activity. The department's studies will encompass anal^ 
sis and evaluation of existing seismograph records and the design. 
Installation, and operation of special Instrumentation to measure 
seiches In reservoirs throughout the State. Correlation of the rec 
ords from the seiche recorders with records from long-period seismc 
graphs will enable the department to determine the probability of 
seiche development In each reservoir and whether the seiches genera 
by a strong earthquake may be In any way destructive. These studle 
may be a joint effort of the Divisions of Resources Planning and 
Design and Construction. 

Geodetic Studies . The measurement of vertical and hori- 
zontal movements of the earth's crust, using geodetic instruments a 
techniques, is another essential phase of the department's program 
for investigating and evaluating the problem of accumulating crusta 
strain. The following studies and activities will be continued a^ 
part of the geodetic phase of the Crustal Strain Investigation: 

1. The department's program of geodlmeter measurements 
will be repeated along the San Andreas fault. These measurements 
are being improved by the adaptation of new techniques for obtalninj 
midline atmospheric measurements. It is planned to extend the 
department's program of geodlmeter measurements to other areas of 
the State where water development facilities are close to other 
active faults. These measurements will assist In distinguishing 


active from Inactive faults and will show the various rates at which 
parts of the earth's crust are undergoing horizontal movements. 

2. Coordination of state and federal earthquake engineer- 
ing survey programs will be continued. Inasmuch as the United States 
Coast and Geodetic Survey has been given primary responsibility for 
long-term earthquake triangulatlon surveys by acu of Congress, coor- 
dination is necessary to eliminate overlapping and duplication and to 
lend more specific direction to the federally financed geodetic pro- 
grams. Federal programs Include fault zone triangulatlon and astro- 
nomic azimuths for the measurement of horizontal crustal movements, 
and precise leveling to detect vertical movements. 

3. The cooperative ultrapreclse triangulatlon project of 
the department and the United States Coast and Geodetic Survey for 
measurement of horizontal movements in the area of junction and near 
approach of the San Andreas, Garlock, and White Wolf faults will be 
repeated when the department's geodlmeter measurements indicate suf- 
ficient crustal movement to warrant the repetition. 

4. The Federal-State Cooperative Leveling Program for 
Subsidence, administered by the department. Is another area of coop- 
ration with the United States Coast and Geodetic Survey. This pro- 
gram provides basic data on subsidence for planning and design 
sngineers in the department, and for other Interested agencies. This 

ooperative program will be continued. 

5. The proposed Federal-State Cooperative Selsmologlc and 
leodetic Programs for Earthquake Engineering, with the United States 

oast and Geodetic Survey, will provide complete analysis and inter- 
pretation of already completed field work of special geodetic repeat 


observations in California fault zones, analyses of existing strong- 
motion seismograph records of California earthquakes, and additional 
special geodetic repeat observations and analyses in fault zones in 
the vicinity of proposed State Water Pacillties, The survey will 
continue to operate and maintain the seismograph stations that have 
been made part of the cooperative program, and will supply personnel 
and services to install, operate, maintain, and interpret records of 
several of the seismographic Instruments and stations recommended by 
the Consulting Board for Earthquake Analysis. This cooperative pro- 
gram does not duplicate the department's Crustal Strain Program, but 
is an essential complement thereto. 

Engineering Geology Studies . Geologic studies are an es- 
sential phase of any thorough study of the hazards of earthquakes an 
crustal movements to manmade structures. Engineering geologists hav 
a public responsibility to ensure that engineers, architects, proper 
owners, and public officials are properly informed with respect to | 
earthquake hazards, without being too reassuring or needlessly alarni 
Ing. A clear idea must be formed of the long-term nature of earth- 
quake risk, as well as its relation to the location of faults and to 
the character of the ground or foundation. The following activities 
and studies are included in the geologic phase of the Crustal Strain- 

1, Detailed seismic microregionalization maps may be 
developed for specific sites and/or critical areas. This will 
entail compilation of the following types of data: 

a. Detailed information on potential activity 

of faults with particular emphasis on those ij 

-32- 1 

faults which may affect existing and proposed 
hydraulic structures, 
b. Characteristics of foundation rocks and 
materials relative to seismic stability. 
These data and seismic microregionalization maps are im- 
portant in any earthquake engineering study, and will be most useful 
in appraising the earthquake and crustal movement hazards at sites 
of proposed facilities of the State Water Resources Development 

2. Geologic interpretation will be provided for the strain 
build-up detected by the geodetic and geophysical measurements being 
made in other phases of the investigation. 

3. Geologic field studies will Include reconnaissance of 
possible sites for future geodlmeter or other geodetic stations, or 
for future installations of geophysical instrumentation such as 
seismographs, quartz-strain extensometers, recording tlltmeters, 
accelerograph, and related types of instrumentation recommended by 
the department's Consulting Board for Earthquake Analysis. 

4. Sites chosen for water development facilities through- 
out the State will be inspected as part of the department's earth- 
quake hazard evaluation studies, and a geologic evaluation of the 
earthquake and/or crustal movement hazards will be made at such 



The primary function of the earthquake engineering studies 
to be conducted by the Division of Design and Construction and the 
Supervision of Dam Safety Office will be the development of procedure: 
and criteria for aselsmlc design of features of the California Water 
Resources Development System and for Investigation of dams under 
Jurisdiction of the department's Supervision of Dam Safety Office 
from the seismic standpoint. These studies will utilize the afore- 
mentioned earthquake hazard studies to obtain an appreciation of the 
earthquake hazards which should be anticipated In any given area. 
The Division of Design and Construction has completed a 
proof test of the Orovllle embankment design. This seismic model 
study was one of several essential engineering studies which have 
been completed In connection with the design of Orovllle Dam. This 

: proof test of the embankment design was conducted on the shaking 
table of the Engineering Materials Laboratory on the Berkeley campus 

. of the University of California, IJie report on this seismic model 

, study will soon be completed 

In Its report of November 19, 1962, the Consulting Board 

! for Earthquake Analysis recommended that the department undertake 

the following earthquake engineering Investigations In addition to 

the basic studies previously discussed: 

"l. Experimental investigations of the strength and 
deformation characteristics of soils under simu- 
lated earthquake loading conditions for the purpose 
of determining the appropriate soil properties for 
use in analyses of earthquake response character- 
istics. Studies should include: 


" (a) Investigations of the strength and de- 
formation characteristics of soils under 
combined static and pulsating loads. 

" (b) Investigations of volume changes and 
strength characteristics of saturated 
granular materials under combined shear 
and vibratory loading conditions and 
also under high confining pressure con- 
ditions associated with large dams with 
the object of determining the pore pres- 
sures likely to develop in embankments 
composed of saturated granular materials 
during earthquakes. These studies should 
be supplemented by investigations of 
volume changes induced in dry granular 
materials by typical earthquake ground 
motions with the object of throwing some 
light on the extent of subsidence of 
such soils as a result of earthquakes, 

"2. Investigation of methods for predicting the danger of 
liquefaction of soils both in the laboratory and in 
the field. This investigation is closely related to 
that suggested in 1 (b) above. 

" 3. Investigation of the stability and deformation of model 
dams during simulated earthquake motions induced by a 
shaking table. Such studies would serve two purposes. 

" (a) As an interim procedure, tests on models 
of proposed prototypes would provide a 
guide to the probable effect of earth- 
quakes on these structures. However, 
this would only be possible for certain 
types of embankments. 

" (b) The results would provide data for de- 
termining the applicability of analyses 
and measured soil characteristics for 
predicting the response of embankments 
and dams to known ground motions. With- 
out such tests it is difficult to see 
how analytical procedures can ever be 
checked under controlled conditions. 

"4. Investigation of the stability against surface sliding 
of banks of granular materials subjected to earthquake 
ground motions, for the purpose of checking the appli- 
cability of available analyses for computing the ac- 
celeration at which sliding is likely to occur and 


for determining the extent of sliding and flattening 
of slopes resulting from a given ground motion. 

"5= Investigations of the dynamic behavior of dams by the 
methods of analytical mechanics. Analyses of the 
elastic response of dams and embankments have been 
developed, but studies of elastic-plastic response 
are required to determine the stresses and displace- 
ments resulting from known earthquake ground motions. 
It is the inelastic displacements which are of pri- 
mary Importance in stability analyses. 

"6. Investigations of the dynamic behavior of existing 

dams by means of field tests using a shaking machine. 
The results of such studies can be Interpreted to 
evaluate the dynamic shear modulus of the soil com- 
prising the dam and can thus be used to check the 
validity of laboratory methods for determining the 
dynamic shear modulus of the soils in advance of 
construction. " 

The Crustal Strain and Fault Movement Investigation and the 

Dther earthquake engineering Investigations herein briefly described, 

lave been undertaken by the Department of Water Resources to provide 

Dbjectlve evaluations of possible hazards at hydraulic structure 

sites as related to the potential effects of California's sporadic 

arthquakes and to develop rational criteria for aseismic design of 

structures at those sites to obviate or minimize the adverse effects 

of future earthquakes. Utilization of the data on earthquake hazards 

and the criteria for aseismic design will contribute to the competent 

design of safe and economical hydraulic structures in all areas of 

the State. 


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RET. tifcB 1 1) 19B5 


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'1 REC'D 


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