Seismic engineering program report, January-April 1979

CECIL D. ANDRUS, Secretary

Geological Survey H. William Menard, Director

This Seismic Engineering Program Report is an informal document primarily intended to keep the ever-growing community of strong-motion data users apprised of the availability of data recovered by the Seismic Engineering Branch of the u.s. Geological survey. strong-motion instrumentation is supported by the National Science Foundation (Grant CA-114) in cooperation with numerous Federal, State, and local agencies and organizations.

This issue contains a summary of the accelerograms recovered from the u.s. Geological survey's (USGS) National Strong-Motion Network during the period January 1 through April 30, 1979. A report on strong-motion instrumentation in the Imperial Valley, California, is presented along with summaries of recent reports, notes on strong-motion availability of digitized data, and additional information pertinent to the USGS and other strong-motion programs. The data summary presented in table 1 includes those accelerograms recovered (although not necessarily recorded) during the period January through April 1979; this procedure will be continued in future issues so that the dissemination of strong-motion information may be as expeditious and current as practicable.

iii The Seismic Engineering Program of

information sources and the

Ronald L. Porcella, Editor U.S. Geological Survey, MS 78 Menlo Park, California 94025 Preface - - - - - - - - - - - -

Strong-motion information, data reports, and availability of digitized

data

2 - Selected accelerograms from the Imperial Valley, California -

Figure 1 - Accelerograph stations in Alaska - - - - - - - - - - - - - - - - 2 - Icy Bay accelerogram from the Alaska earthquake of

February 28, 1979 - - - - - - - - - - - - - - - - - - - - - -

3 - Yakutat accelerogram from the Alaska earthquake of

February 28, 1979 - - - - - - - - - - - - - - - - - - -

Page

iii

ILLUSTRATIONS

v RECENT STRONG-MOTION RECORDS

A occurred on February 28, 1979 (1127 local time) approximately 75 km north of Icy Bay, Alaska. depth of about 15 km (+10) in the vicinity of the St. Alaska (Lahr and others, 1979), which is a highly faulted and tectonically very complex region. were Survey's Icy Bay station, Shell Oil company's Munday Geological maximum recorded ground accelerations and the corresponding epicentral distances were 0.16 .2. (73 km) at Icy Bay, 0.06 .s_ (92 km) at Munday Creek, and 0.09 .s_ (161 km) at Yakutat (table 1). informal operated Lamont-Doherty University of Alaska, and Shell Oil Company (see within this network that did not trigger include Cape Yakataga, Cordova at epicentral distances of 79 km, 200 km, and 214 km, respectively. and Yakutat accelerograms (fig. 2 and 3), and the Munday Creek records have been digitized~ information accelerations, velocities, and displacements and velocity response spectra is available from the u.s Geological survey.* The California earthquake of January 1, (1614 local time) was located in Santa Monica Bay at a depth of about 6 km~ slight damage (MMI VI) was reported in Canoga Park, Sherman Oaks, Woodland Hills, Los Angeles, and El Segundo (Waverly Person, oral commun., June 20, 1979). recovered at strong-motion stations in the Los Angeles and San Fernando Valley areas~ eight of these contain peak accelerations

*The Munday Creek records were made available to the USGS by the Shell Oil Company on an "as is" basis. part of the data obtained from the February 28 event, the USGS is satisfied that the accuracy of the data is comparable to that obtained at other stations.

The hypocenter was located at a

Strong-motion accelerograph records recovered

fig.

magnitude by R. L. Porcella

These stations are part of an strong-motion the u.s. Geological Observatory,

In making them available as a (Ms)

u.s.

(ML)

and greater than five percent .2. (table 1). peak horizontal ground acceleration (0.09 .s_) was recorded at the Topanga Fire Station at an epicentral Additional accelerograph sites maintained by the State of California located from Ventura south to Santa Catalina Island and east to Irvine (Rich McJunkin, oral commun. March 21, 1979).

Other accelerograph records recovered during this reporting southern coast of Hawaii~ east of Seattle,

and five events in the San Bernardino-San Jacinto California listed in table 1 was taken primarily from the Preliminary Determination of Epicenters, published by the u.s. Geological Survey.

A total of 44 accelerograms was recovered from the Strong-Motion January through April, 1979~ this national network is supported by the National Science Foundation and was made possible through the cooperation of educational institutions as well as numerous Federal, organizations. program is motion and the response of various types of engineered damaging earthquakes and to disseminate these data to the international community involved in earthquake engineering research and design.

Reference: c., Fogleman, K., and Blackford, M., 1979, Interim report on the st. Elias, Alaska earthquake of 28 February 1979: Open-File records

to record both strong ground

Lahr, J., Plafker, G., Stephens,

and The major objective of this of were recovered

km.

p.

., Du~:Y~ ..

,t/"'

T I

v U.S. STRONG-MOTION NETWORK Station No. 2728 59.51N, 139.63W Yakatat, FAA-VOR Bldg.

--~-START ---------------~IOSJECONDS__-----_-_l~~~COND~- -

v

v U.S. STRONG-MOTION NETWORK Station No. 2734 59.97N, 141.64W

T= 090°

CONSTANTS Sens. = 1.65 cm/g Film Speed = Per. = .037 sec 2 time marks/sec Damp. = 0.61 crit I 5 em Sens. = 1.77 cm/g Per. = .037 sec Damp. = 0.57 crit

Sens. = 1.72 cm/g Per. = .038 sec Damp. = 0.61 crit STRONG-MOTION INSTRUMENTATION

R. L. Porcella and R. B. Matthiesen

From a paper to be presented at the Mexico-California Symposium, The Human Settlements

Institute Technologico Regional de Tijuana September 4 - 8, 1979, Tijuana, Mexico

The 192~ World Engineering Congress in Tokyo, Japan, has been cited as possibly the major earthquake engineering investigations in the western United States discussions at this conference convinced many American engineers of the urgent need for the united States to move ahead rapidly in the investigation of the engineering aspects of seismology, instrumentation suitable for recording ground motions of a potentially damaging level. 1931, the u.s. congress allocated funds and designated responsibility to the coast and Geodetic engineering seismology program.

The seismographs began in July 1932, and just eight months later the disastrous Long Beach earthquake triggered accelerographs at three southern California stations. records not only provided useful information about damaging earthquake motion, but also helped to justify the program and furnished an addi tiona! instrumentation effort. strong-motion installed, commercial Avenue.

In recent years, the Imperial Valley of california has been one of the seismically most active regions in the continental United States. the early part of this century, no less than 13 shocks of MMI VIII or above have been attributed between 1906 and 1934 (Ulrich, 1941). On May 18, 1940, a magnitude 7.1 earthquake was responsible for heavy damage throughout the Imperial valley and was followed by a swarm of more than 30 recorded shocks during the eight triggered the strong-motion instrument in El centro and those as far away as San Diego, san Bernardino, and Los Angeles. Centro accelerogram is still used worldwide in earthquake engineering design studies as a

IN THE IMPERIAL VALLEY,

on the San Andreas Fault:

including one in El Centro on

Despite the scarcity of records from

INTRODUCTION

(Cloud, 1964).

for Within two years, 51

Imperial Valley region beginnings

The 1940 El of

an representative ground motion from a strong local earthquake.

The Imperial Valley is situated within the central region of the Gulf of California physiographic province and broad, trough filled with Cenozoic deposits derived from the surrounding mountain ranges (Dibblee, 1954). Although fault-associated uplift has occurred along the ma~gins of this linear trough, the regional geologic setting suggests that this depression is not a simple graben (Biehler and others, 1964; Sharp, 1972).

The seismicity of this region has been widely characterized by both earthquake swarms as well as Although the nature of this latter activity grades activity, investigations complexity of earthquake sequences may be most closely complexity of the region This observation is in good agreement with recent region (for example, Sharp, 1972; Henyey and Bischoff, 1973; and Johnson and Hadley, 1976) and emphasizes the difficulty inherent in making definitive hazard evaluations for the Imperial numerous empirical studies have been made that attempt to define recurrence intervals for earthquakes in various magnitude ranges.

For the Imperial Valley region (15,102 km2), 786 earthquakes (greater than magnitude 3.5) from 1932 to 1971 were used as the basic data set to compute recurrence intervals of eight months for a magnitude 5-5 1/2 event, and 6.7 years for a magnitude 6-6 1/2 event Similarly, 1870-1970 were used by Matthiesen (1978) in order to establish "projected histories" of possible provide some insight into the return of data that could be expected from strong-motion networks in various locations throughout the United States. Imperial Valley indicates that a significant concentration of seismic activity throughout the second half of the study period could have provided a fairly consistent rate of strong-motion this is a region where further development of the existing network is warranted.

Background

and very complex structural

region.

and intensity data from

A projected laistory for the

and suggests is part of a

the (Richter, 1958).

activity.

that Initially, accelerograph was installed in El Centro at the commercial Avenue Station as a part of a program strong-motion records from several regions in the western United States. 1970's, stations were established in the Imperial valley as a part of the development of a network along the San Jacinto fault, but it was not until 1975 that a cooperative effort was made by Technology (CIT), the California Division of Mines and Geology, and the u.s. Geological survey to develop a specialized network of strong-motion fulfill the specific research needs required by studies of source-mechanism, ground motion attenuation, and structure response.

An array of 13 accelerograph sites at 3- to 5-km spacings and transverse to the 1940 earthquake surface rupture was established for the purpose of obtaining information on the attenuation distance from the causative fault. crosses the Imperial fault (fig. 4) for a total length of about 45 km and contains accelerographs (school, hospital) and in small (approx. 2 m3)

fiberglass (a Kinemetrics model SMA-IT*) with a triggering (usually within 0.2 s of the first P-wave receiver earthquake record.

working Administration, the u.s. Geological Survey is presently installing a linear array of six triaxial accelerometers in order to record horizontally propagating surface waves, which will provide measurements of the differential motions of the ground surface. extends in a north-south direction for a total distance of 305 m, with accelerometers located at 0, 18, 55, 128, 214, and 305 m. The recorders· and a SMA-IT accelerograph are located in a small concrete block structure 8 m south of the array. spacings are such that the distances between any two stations are similar both to the typical distances between bridge piers and to the half wavelengths of relevant shear wave motion (Noel Bycroft, oral commun., Mar. 20, 1979). Since the differential displacement (doubly integrated acceleration) between two accelerometers will be used as a measure of potential

*Any use of trade names in this report is for descriptive constitute endorsement by the u.s. Geological Survey.

Objectives

the California Institute of

housings.

only and does to

In the early accelerograph

a WWVB radio time

not structure, the recorders must be perfectly synchronizedi interconnected Technology DCA-300) will be used with the six triaxial accelerometers primary objective of the array, then, is to obtain differential ground displacement data for use in the aseismic design of dams, pipelines, and particularly bridge structures.

The California Division of Mines and Geology, working with the State Department of Transportation survey, has overpass at Interstate 8 in El Centro with a 26-channel (Kinemetrics instrumentation scheme includes strategically placed accelerometers strong-motion data for use in the evaluation of the structural response of the overpass during potentially damaging earthquakes. major objective of this part of the Imperial valley network is to record data such as modal response, damping characteristics, and generalized motions and displacements of a typical overpass structure and to develop a standardized procedure by which these data can be analyzed to produce the maximum amount of information (Chris Rojahn, oral commun., Mar. 28, 1979).

The six-story Imperial County Services Building in instrumented Strong-Motion (CSMIP)i a 13-channel remote recording system (Kinemetrics accelerometers located at the ground, second and fourth floor, and roof levels (Rojahn and Ragsdale, 1978). reinforced concrete structure, rectangular in plan, designed to resist lateral forces in the transverse (N-S) direction by shear walls and in the longitudinal direction by frame action. Three ambient-vibration measurements were made at the roof level of this building in June 1978i readings were taken at the east end, near the center, and at the west end of the building. objective Instrumentation Program structural buildings during earthquakes and thus provide information that will lead to improved earthquake resistant design and public and reduced property losses in future earthquakes (Wootton and others, 1976).

CRA-1)

ultimately for this digital

the is of potentially

(DSA-302-M}.

u.s.

CRA-1).

CSMIP to record reason,

has been California Program

(velocity)

SALTON SEA

• SUPERSTITION

MOUNTAIN ePARACHUTE TEST FACILITY

• PLASTER CITY

eN0.13 CALIPATRIA

IMPERIAL

eN0.12

Array • N0.1

eN0.2

eN0.3

HOLTVILLE

10/15/79 Plans for future USGS efforts in the Imperial Valley include an expansion of the network into more of a grid-type array by the addition of perhaps 12-15 accelerographs and a redistribution of several of the array instruments. would be based on the historic pattern of seismic activity, as well as on the location of epicenters of recent earthquakes (since 1973) recorded by the 22-station, CIT-USGS Imperial Valley seismographic network example, Hileman and others, 1973~ Fuis and others, 1978).

Two SMA-lT accelerographs will be added to the El Centro commercial Avenue station, one in the basement and one outside the building at ground level, perhaps 75-100 m away, where any effects of the building on the recorded motion would be minimal. studies of deposits with man-made structures indicate that the presence of a massive building (such as the Commercial Avenue station) can alter the input ground motion to perhaps a greater degree than previously considered. anticipated that the installation of these two identical, interconnected accelerographs will provide the comparative data necessary for a differences in the spectral content of strong ground motion "building" information interaction studies of the 1940 El centro accelerogram.

Since installed in El Centro in July 1932, more than 250 accelerograms have been recovered from the Imperial Valley region~ nearly 200 of these records have been recovered since January 1975, and they contain accelerations as high as 30-50 percent ~ from moderate-size (magnitude 4-5) earthquakes (see table 2). It should be noted that all of the records in table 2 recorded prior to 1966 were recovered at the commercial Avenue station, . the only station in the Imperial Valley during that period. levels reported after 1966 is due to the increase in the number of stations in the area and the consequent overall decrease in the epicentral distances listed in table 2. Because of the extremely short durations of these high accelerations, the data are of minimal many of seismologic information relevant to epicenter determinations, source-mechanism valley region (for example Porcella, 1978).

Future Activities

The locations of new stations

STRONG-MOTION DATA

Thus, the increase in acceleration

engineering the records at

"freefield"

wave studies of surficial

and as additional in soil-structure

propagation, of the (for

and The Imperial Valley strong-motion network operated by the u.s. Geological survey is the result of the cooperative efforts of the California California Division of Mines and Geology, the Federal Highways Administration, and the u.s. Geological pattern of seismic activity and recent smallto moderate-size earthquakes have been used as a basis for planning the deployment of accelerographs region. accelerograph stations: Interstate 8~ the six-story Imperial county Services Building in El Centro~ a 13-station array across Imperial specialized array for measuring differential ground "freefield" sites located from Niland south to Calexico, and from Superstition Mountain east to objective of this network is to accumulate data for use in studies of source mechanism, structural attenuation in the Imperial Valley region.

AcknowZedgement - The present Imperial Valley possible through the generous cooperation of many individuals, private organizations, and government agencies that granted permission to install and maintain instrumentation on their property. logistical cooperation District granting permission to operate strong-motion instrumentation District property is hereby acknowledged.

Biehler, s., Kovach, R. L., and Allen, c. R., 1964, Geophysical framework of the province: Petroleum Geologists Memoir 3, p. 126-296.

Cloud, w. K., 1964, The cooperative program of earthquake investigation, in carder, investigations States, commerce, Publication 41-2, p. 3-4.

Dibblee, T. w., 1954, Geology of the Imperial valley region, California, in Jahns, R. H., ed., california Division of Mines and Geology Bulletin 170, v. 1, ch. II, p. 21-28.

Survey.

The network presently contains 28

SUMMARY

Highline Canal.

REFERENCES CITED

D.

an overpass on u.s.

In and Imperial Board

S. , in the u.s. and

ed. , - western Department of Geodetic

Fuis, G. s., Johnson, c. E., and Jenkins, D. J., 1978, Preliminary catalog of earthquakes Valley, California, October 1977 - December 1977: Open-File Report 78-673, 41 p. Henyeyi T~ L. and Bischoff, J. L., 1973, Tectonic elements of the northern part of the Gulf of California: Society of America Bulletin, v. 84, p. 315-330. Hileman, J. A., Allen, c. R., and Nordquist, J. M., 1973, Seismicity of the southern California region 1 January 1932 to 31 December 1972: California Institute of Technology, Seismological Laboratory, p. 72-75. Table 2.- Selected accelerograms from the Imperial Valley strong-motion network

**Information about these accelerograms is available from the u.s. Geological Survey, Seismic Engineering Branch, Menlo Park, Calif. Date

in northern Time (PST) Magnitude accl. (!l) dist. (km)

Imperial

Geological 6.5 3.0 s.o 4.0 7.1 6.5 5.6 5.5 6.3 3.8 4.3 3.9 5.4 6.8 6.4 6.3 6.5 5.9 5.1 4.8 4.7 4.2 4.1 3.9 4.9 4.2 3.9 4.0 3.9 4.2 3.3 4.1 Epicentral Peak

0.18 .04 .04 .01 .31 .06 .03 .04 .02 .06 .03 .01 .08 .OS .01 .01 .12 .02 .03 .16 .13 .10 .15 .14 .11 .13 .16 .14 .so .41 .25 .23

Johnson, c. and Hadley, o., 1976, Tectonic implications of the Brawley earthquake California, January 1975: Society of America Bulletin, v. 66, p. 1133-1144. Matthiesen, R. B., 1978, On the development of strong-motion networks in the United States: Open-File Report 78-1024, 91 p. Porcella, R. L., 1978, Recent strong-motion records, in Seismic engineering program report, May-August 1978: Geological survey Circular 785-B, 18 p. OS

A001, T277-T285

swarm, B024 T274 T275 T276

T286 T287 T288 T289 ** T290 T291 T292 AOll A012 T293 A019 ** ** ** ** ** ** ** ** ** ** ** ** ** ** **

Imperial valley, Seismological

u.s.

Richter, c. F., 1958, Elementary seismology:

San Francisco, Freeman and Company, p. 66-78.

Rojahn, c. and Ragsdale, J. D., 1978, Building California Program: Convention of Association California, in press.

Sharp, R. v., 1972, Tectonic setting of the Salton Trough, in The Borrego Mountain earthquake of April u.s. Geological Survey Professional Paper 787, p. 3-15.

Ulrich, F. P., 1941, The Imperial Valley earthquakes of 1940: Seismological Society of America Bulletin, v. 31, p. 13-31. Wootton, T. M., Wells, w. M., and Power, J.

H., Strong-Motion California Division of Mines and Geology Special

SUMMARIES OF RECENT REPORTS*

by s. B. Hodder, R. I. Skinner, R. T.

The Milford Sound earthquake was recorded by three-component accelerographs at Milford Hotel, acceleroscope at Haast. records are of particular interest because the intensities covered by the recorders were exceptionally low magnitude of 7. acceleration, from about 0.093 .2 recorded at Milford Hotel· to about 0. 033 .2 at Te Anau, together relatively severe shaking, were consistent with digitization calibration and correction of the Milford Hotel accelerogram are described and the acceleration response spectra have been plotted.

Reference: National Society for Earthquake Engineering, v. 11, no. 3, September 1978. instrumentation Strong-Motion Proceedings,

STRONG-MOTION RECORDS OF THE MILFORD SOUND EARTHQUAKE OF MAY 4,1976

Hefford, and P. M. Randal

for an earthquake The low values of maximum

Te Anau These strong-motion

low intensities.

of the New phase Instrumentation 48th

on Program:

p.

CATALOG OF STRONG-MOTION ACCELEROGRAPH STATIONS

by Hung-Chie Chiu and wen-Shiang Liu

In 1971 observation and research program was started by the National Science council, Republic of China. accelerograph network throughout the Taiwan area was one major item of the program. Since then, the number of instruments has steadily increased. accelerographs country. included in this publication.

In the past few years, several tens of records were collected. these records contain accelerations barely above the trigger level (0.01 _2) of these instruments. April 14, earthquake in southwestern Taiwan produced unusually high accelerations at some sites. In particular, magnitude above 6.0 have occurred during 1978, resulting in a number of records of engineering interest. publication researchers and engineers of the existence of these records.

The records are arranged by individual earthquake, Information about depth, and earthquake is provided. observed intensity values Bureau essentially the same as the JMA intensity scale, are also given for reference.

Reference:

Academia Sinica, Taipei, Taiwan, Republic of China, December 1978, Volume 1.

*Inclusion sources is intended as a service to our readers endorsement of these reports by the u.s. Geological Survey.

AND RECORDS IN TAIWAN

Institute of Earth Sciences,

This situation was changed on when

in the or1g1n time, Richter

At the end of 1978 42 operating recording

The purpose of this inform

order.

focal of each the is

ON THE DEVELOPMENT OF STRONG-MOTION

To establish engineering design criteria and to evaluate earthquake hazards, studies of the attenuation of strong ground motion and of regional differences in these characteristics are the most additional strong-motion data are required. Evaluations of structures soil-structure interaction on such response are the strong-motion studies relative to engineering research and design applications. local site resulting from soft surficial differences in motion at nearby points on the ground surface) and of soil failure phenomena (liquefaction or importance, important placed in several regions where the potential for soil failure is recognized and where a sufficiently high rate of return of strong ground motions is likely.

A review of the strong-motion activity in each region of special ground motion and structural response studies should Mendocino area, along the Hayward fault, in the Gilroy Transverse Ranges, and in the Imperial Valley of California. are few studies of justified on the basis of anticipated return of data, networks to justified in the Mississippi Valley and on the Island of Hawaii. Gulf of Alaska and in the Aleutian Island arc are areas of consider able activity, but the logistical instruments and the locations of the islands relative to the sources of major earthquakes impose additional constraints, which dictate that only a minimum network of instruments for ground motion studies be developed in this region. Sound trough are events have occurred in the recent past, but the uncertainty current activity precludes the development of more than stations in these regions. and Long Valley areas in California and the Flat-head Lake area in Montana are areas in which a occurring.

INSTRUMENT NETWORKS IN THE UNITED STATES

buildup This activity must be monitored, by R. B. Matthiesen

landslides)

outside of California there in which structural

Western Nevada and the Puget regions

inelastic response of the

Along the shore of the

are of are sufficiently arrays

be and plans should be made to respond to any indication that a major event is likely to occur. should structures, such as darns and nuclear power plants, clearly include many of the regions that are of research-type network strong-motion instruments, other instruments should be maintained in a stand-by condition at several locations for rapid deployment to study ground motions from aftershocks.

The importance of adequate strong-motion data to the fields of geophysics, seismology, and earthquake urgency on the development of the network, but the inherent long-term nature of the process places the burden on the present generation to plan wisely for future generations who will utilize the data in research, design, operations, and regulation.

Reference: Report 78-1024, October 1978, 91 p.

SANTA BARBARA, CALIFORNIA, EARTHQUAKE

by w. H. K. Lee, c. E. Johnson, T. L. Henyey,

The ML5.1 Santa Barbara earthquake of August 13, 1978 occurred at lat 340 22.2'N, long 1190 43.0 'W, Barbara, Calif. at a depth of 12.5 krn in the northeast Santa Barbara Channel, part of the Transverse province. characterized east-trending reverse faults and rates of coastal uplift that have averaged up to about 10 m/1000 years over the last 45,000 years.

No surface rupture was detected onshore. Subsurface rupture propagated northwest from the main shock toward Goleta, 15 km west of Santa Barbara, where a maximum acceleration of 0. 44 s_ was measured at ground level and extensive minor damage occurred~ only minor ln)uries constrained fault-plane solution of the main shock and distribution of the aftershocks indicate occurred north-dipping reverse faults~ inadequate dip control precludes good correlation with any one of earthquake been larger and rupture propagated to the southeast or a greater distance to the The be installed

u.s. Geological Survey Open-File

OF AUGUST 13, 1978 AND ITS MAJOR AFTERSHOCKS

relatively low priority for studies.

and R. L. Yerkes

Ranges part of by

reported.

left on in which to

4 krn

reverse-oblique west-northwest-trending, instruments monitor

faults.

the northwest, it could have posed a hazard to oil-field solution and aftershock pattern closely fit the model of regional deformation, and the solution closely resembles previously mapped events located within a 15-km radius.

Reference: 797, 1978, 11 p.

ENGINEERING FEATURES OF THE SANTA BARBARA EARTHQUAKE OF AUGUST 13, 1978

A report on research supported by National Science Foundation, Earthquake E~gineering Research Institute, and University of

by Richard K. Miller and Stephen F. Felszeghy

Although the Santa Barbara earthquake was only a moderate seismic event, several of its features were unusual and interesting from an engineering point of view. these features are the geographical asymmetry of strong ground shaking, accelerations instruments, and the differences in reported magnitudes for the event. also provided a picture of the performance of modern California buildings in a moderate earthquake. preliminary investigations of some of the more striking engineering features of the earthquake, details of the geologic features, strong-motion records, and effects of the earthquake on the various facilities in the area.

Reference: Barbara, Report UCSB-ME-78-2, December 1978, 133 p.

PROCESSED DATA FROM THE PARTIAL STRONG-MOTION RECORDS OF THE SANTA BARBARA EARTHQUAKE OF AUGUST 13, 1978

by L. D. Porter, J. T. Ragsdale, and

On August 13, 1978 a moderate magnitude earthquake (ML Technology) occurred in the ocean 6 km south of Santa Barbara, California. had a focal depth of 12.5 km and was located at lat 34.37~ and long 119.720W.

The Santa Barbara area has a moderate amount of instrumentation, which includes 27 accelerographs epicenter. triggered by the August 13 main eventi eight of these instruments belong to the California operations. The

u.s. Geological Survey Circular

California.

Presented in this report are

University of California, Santa

5.1, Calif. Institute of

within Eleven accelerographs fault-plane

the large peak strong-motion

the were Division of Mines and Geology (CDMG), and one each to southern California Edison Company, the u.s. Bureau of Reclamation, and the u.s. Geological Survey. the Santa significant enough to require digitization by the State Program: Building, (2) Santa Barbara-UCSB North Hall Building, and (3) Santa Barbara-UCSB Goleta. The subject of this report is the record analysis of approximately the first 10 s of earthquake-generated stations. include uncorrected accelerations, corrected accelerations, velocities, and displacements, and response spectra.

Reference: Geology Preliminary Report 23, 1979, 93 p.

COMPILATION OF STRONG-MOTION RECORDS RECOVERED FROM THE BISHOP, CALIFORNIA EARTHQUAKE OF OCTOBER 4, 1978

A moderate magnitude earthquake 5.7, Berkeley seismographic station) occurred approximately California, on October 4, 1978. depth of 4.8 km and was located at lat 37.518~ and long 118.7050W.

The instrumented by 11 accelerograph sites within 100 km of the epicenter; these instruments are owned and operated by the Office of Strong-Motion Studies, California Division of Mines accelerograph produced records of the Bishop earthquake.

As an aid to the analysis of records, stations are listed alphabetically and in a north-south pattern. of triggered stations with respect to the earthquake epicenter are listed by range and azimuth. network for the Bishop region is examined with respect to epicentral distance. peak (horizontal components) are listed along with their corresponding azimuths.

Reference: Geology, preliminary results, OSMS Report 78-7.1, November 1978, 29 p.

California Division of Mines and

by R. D. McJunkin

and Geology.

California Division of Mines and Three CDMG stations in area

km northwest of Bishop,

The earthquake had a focal

ground accelerations at this

INTERIM REPORT ON THE ST. ELIAS, ALASKA EARTHQUAKE OF FEBRUARY 28, 1979

by J. c. Lahr, George Plafker, c. D. Stephens K. A. Fogleman, and M. E. Blackford

On February 28, 1979 an earthquake with surface wave magnitude (Ms) of 7. 7 occurred beneath the Chugach and St. Elias Mountains of southern Alaska. complex northwestward convergence between the Pacific and North American plates. seismic network in southern Alaska has been pperated by the USGS since 1971, and it was greatly expanded along the eastern Gulf of Alaska configuration Technical available in published earthquake catalogs; preliminary analysis of the data from this network covering the period from september 1, 1978 through March 10, 1979, as well as worldwide data for the main shock, is discussed in this paper.

Reference: Report 79-670, 1979, 35 p.

PRELIMINARY ANALYSIS OF STRONG-MOTION RECORDS OBTAINED AT ULCINJ, BAR, AND PETROVAC FROM THE APRIL 15, 1979 MONTE NEGRO, YUGOSLAVIA EARTHQUAKE

by Nove Naumovski, Dimitar Petrovski, Vidoje Zelenovic, Jakim Petrovski,

The April 15, 1979 Yugoslavia earthquake in the recorded instruments located throughout an area of approximately instruments are part of the strong-motion instrument network maintained by the Institute of Earthquake Engineering Skopje.

For the purpose of preliminary analysis, only the strongest motion of three records from an area of about 60 km along Adriatic coast was "Olivia" Hotel, Ulcinj - "Olimpic" Hotel, and Bar - Town Assembly building. only three records for analysis was based primarily on the limited time available and the urgent need for definition of the main earthquake effect upon the structures located in the epicentral region. addition to the old traditional stone masonry buildings, a number of modern structures wer~ seriously damaged or destroyed.

u.s. Geological survey Open-File

Engineering This is a region of resulting

km2.

selected:

In this area, in from

The current is shown. network

the Reference: Engineering and Engineering University "Kiril and Yugoslavia, Publication No. 64, April 1979.

U.S. STRONG-MOTION NETWORK DATA

A Strong-Motion System (SMIRS) has been developed to provide up-to-date records and the circumstances in which they were recorded. through duplex) • information within it is incomplete and needs to be verified. A user's manual is available (Converse, 1978). dial (415) 329-8600. on line, type: you will be given instructions.

The February 9, 1971 San Fernando, California, earthquake records digitized by Technology (CIT) (Hudson, 1976) • and analysis of the data have been presented in a series uncorrected accelerations, velocities, and displacements, (3)

response amplitude spectra. are available through the National Technical Information Service (NTIS).

The digitization and analysis of significant records subsequent to the San Fernando earthquake have been carried out by the u.s. Processing and analysis of this data are presented in a Reports. available from the USGS, Open-File Services Section.

The records collected by the State of California Strong-Motion being handled by the Office of Strong-Motion Studies (OSMS), California Division of Mines and Geology. these analyses will be available from OSMS.

The digitization program are available from the Environmental Data and Information Service (EDIS) and the National Information Service for Earthquake Engineering at the University of California, magnetic tape digital data from subsequent

OF DIGITIZED DATA

a data The system is operational, but the

When published, these reports are

digitization and analysis of

enter your name SMIRS, and

most to that the California

spectra, All of these data reports

series of USGS Open-File

When the system comes

and of Seismology, Metodij", Skopje,

the significant event Institute of

containing (2)

(USGS}.

The years will be available from EDIS and NISEE at approximately the same time as the data reports are published.

References: Converse, A., 1978, Strong-motion information retrieval system user's manual: u.s. Geological Survey Open-File Report 79-289' 51 p.

Hudson, D. E., 1976, Strong-motion earthquake California Institute of Technology, EERI report 76-02, 72 p.

FOREIGN STRONG-MOTION DATA

Because of the long history of close cooperation between the u.s. and the Central and South American strong-motion programs, much of the data from those programs are available from the same sources as the u.s. data (see strong-motion hemisphere Strong-Motion operated by the USGS.

The USGS does not attempt to obtain first-class foreign organizations reports comparable to those prepared by the USGS. Abstracts of the data reports from such organizations are presented Seismic Engineering Program Report series, and through informal arrangements, copies of the data and records are made available.

EDIS/NOAA WORLDWIDE

A worldwide collection of strong-motion seismograms scientific available from world Data Center A for solid Earth Geophysics Geopohysical Center (NGSDC). the strong-motion database include Australia, Italy, Japan, New Zealand, Rumania, U.S.S.R., and Yugoslavia. has furnished· records from its network of cooperative strong-motion stations, including those in central and South America.

Copies available on 35-mm film, on 70-mm film chips, as paper copies, and as digitized data on punched cards or magnetic tape. A listing of most records can be obtained from the world Data Center Seismograms and Strong-Motion Records, Report SE-6". This catalog can be ordered from NGSDC for $ 2 • 0 0.

The most records recorded in the United states and Latin America between 1931 and 1971 have been copied on eight reels of 35-mm film accelerograms - index volume:

STRONG-MOTION DATA

of below).

data from be Information Retrieval

and and Solar-Terrestrial Countries contributing to

The u.s. Geological survey

strong-motion about western in the System

(12x reduction) (approximately ax reduction). are available records are continued on additional chips. The 35-mm film copies can be purchased for $20 per reel, the complete set of reels for $130.

Full-size paper copies (12" x 36") are available for many of the events in the United States and Latin America at a cost of $1.50 per available as paper copies, but at a reduced scale.

Japan magnetic tapes stations located in the western Pacific Ocean (the Japanese Islands, New Guinea, and New Britain). A series of 400 u.s. strong-motion records (1933-1971) California Institute of Technology and are now available on six magnetic tapes. u.s. Geological post-1971 records from its network; they have generated five tapes of strong-motion records recorded from 1967 to 1975 in the United States and Latin America (Chile, Nicaragua, San Salvador, and Mexico).

Other digitized cards containing strong-motion records from the March (recorded in Bucharest); the Gazli earthquake of May 17, 1976, in uzbek, USSR; and three earthquakes in the New Madrid seismic zone (located in midcontinental United States) in 1975 and 1976.

Recent acquisitions include a magnetic tape of strong-motion records triggered by a swarm of earthquakes that rocked northern Italy near the town of Friuli in 1976; these were compiled by the National Commission for Nuclear Energy and have been given to the Center for distribution.

A table strong-motion records available on magnetic tape may be obtained free of charge from EDIS/NOAA. may be purchased either format at $20 per record (including all three instrument components) or in tape format at $60 per tape.

Checks or money orders should be made payable to "Commerce/NOAA/NGSDC"; should be addressed to EDIS/NOAA (see address below). Phone: (303) 499-1000, ext. 6744; FTS phone 323-6477.

record.

Digitized strong-motion records for $.50 per chip;

were digitized by the

1977 earthquake in Rumania

in punched card film The film chips

6. u.s. Geological survey Seismic Engineering Branch 345 Middlefield Road--MS 78 Menlo Park, CA 94025 DATA SOURCES

reports or information regarding records and data, address Reference Error

CIT; EERL S-M earthquake accelerograms, digitized & plotted data; vol II, III, IV; Part B; Rcord 1037 (1966 Parkfield earthquake)

same as above: vol I, II; P4rt C Record 1041 (1971 San Fernando earthquake; Component direction - Pacoima Dam accelerogram)

USGS S-M Station 2420 New Madrid, Missouri (Component direction events of 6-13-75 and 3-24-76)

USGS S-M Station no. 181; Los Angeles, 640 Marengo, 1st floor (Component direction prior to 7-15-70) NOTE: Since 7-15-70, the 1st floor (also 4th floor and roof) component directions are:

USGS S-M Station No. 125(828); Lake Hughes Array Station 1 (lA) Component direction:

event 9/12/70

event 2/9/71 Correction

L - N21E V - Down T - N69W

L - N21E V - Down T - S69E Temblor, Calif. USGS Station No. 1438 35 42'36" N 120 10'12" w

Event

28 August 1978 - 17 January 1979

s. Hawaii Epicenters and magnitudes unknown

S. California

34.15 N, 116.97 W

Magnitude 4.1

31 December 1978 0323 UTC

Seattle, wash.

47.58 N, 121.85 W

Magnitude 4.0

1 January 1979 2314 UTC

s. California

33.93 N, 118.70 W

Pahala, Hawaii Kau Hospital (USGS)

wahaula, Hawaii Visitor Center (USGS)

Kilpatrick School Malibu, Calif. (USGS)

Monte Nido Fire Sta. Malibu Cyn, Calif. (USGS) one additional record recovered at Wahaula during this period; maximum acceleration less than 0.05 .S.·

(ACOE) t Station coord.

19.20 N 155.47 w

19.33 N 155.03 w

33.98 N 116.99 w

34.09 N 116.92 w

34.08 N 117.05 w

34.11 N 117.17 w

47.14 N 121.93 w

34.084 N 2.4 118.599 w

34.093 N 2.2 118.836 w

34.08 N 118.69 w

Up

up

up

201 Ocean Ave. Santa Monica, Calif. (OTA) Basement

lOth floor

Icy Bay, Alaska Gulf Timber co. (USGS)

Morongo Valley F.s. MOrongf Valley, Calif. 116.58 w (USGS) from a reproduction of records owned by ocean Tower Apartments, Santa Monica, Calif.

California Strong-Motion Instrumentation Program (CSMIP) sites; stations that were triggered include Santa Catalina, Culver City, Inglewood, University, of California at Los Angeles, Hollywood Storage, Century City, Long Beach (2), Irvine, Sherman Oaks, and Ventura (Rich McJunkin, (oral commun.).

vault Station coord.

34.05 N S-t Direction

(s)

15 March 1979 2307 UTC s. California 34.33 N, 116.44 W Magnitude 5.0

ACOE - u.s. Army Corps of Engineers CDWR - California Dept. of water Resources CLA - City of Los Angeles DOE - u.s. Department of Energy LOGO - Lamont-Doherty Geological Observatory MWD - Metropolitan water District of southern California OTA - Ocean Tower Apartments, Santa Monica USGS - u.s. Geological Survey VA

s-wave minus trigger time.

Unless otherwise noted, maximum acceleration recorded at ground or basement level.

Time duration between first and last peaks of acceleration greater than 0.1 ~· - Veterans Administration t - WWVB time code is incomplete or nonexistent, correlation of accelerogram with event is questionable.

*-S-t time is questionable or cannot be determined.

**-Denotes maximum acceleration is less than 0.05 ~ at ground stations or less than 0.10 ~ at upper floors of buildings. Station name (owner)

Morongo Valley F.S. Morongf Valley, Calif. (USGS)

Note: Additional records recovered at CSMIP sites include those from Joshua Tree, Palm Springs, Desert Hot Springs, Palm Desert, and San Bernardino (Rich McJunkin, oral commun.). Station coord.

34.05 N 116.58 w Direction Max acc1. Duration S-t

(s)

Where this page came from

This page was imported from U.S. Geological Survey. Published by the U.S. Geological Survey and, as a work of the United States government, in the public domain.

Nobody has written it yet — it is the source material at a new address, which is why search engines are asked to skip it and why no one earns from it. It is up for grabs: take it on, and it is yours to rewrite and to earn from.