California Geology Magazine September 1991

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CALIFORNIA

GEOLOGY

A PU8UCATlOHOF THEDEPARTMENT OF CONSERVATION

DIVISION OF MINES AND GEOLOGY

Slale 01 c . I I ! _ PETE WILSONG o The DOUGlAS P WHEELER

Stcreraty lor

DIpIrIIf*'Il 01 eoo - _ EDWARD G HEIDlGa.-

o._olMinft&OeoIogy JAMESF DAVIS

SUJI. ~ I o g J S I

CAliFORNIAGEOlOGY

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- ... ",.IftIO&t.... e-.lluMd_oliCllOO'CIhI . . . . . . . -...-.---ntE CONCLUSIONS AND OPINIONS EXPflESSED INARTICLES ARE SOLELY 1I;05e OF THE AUTHORS ANDARE NOT NECESSARILY ENDORSEO llY THE OEPART"'ENT OF CONSERVATION

Co.__al/ lOl l idt.__ IOe- CAlIFOA

NlA GEOlOGY, Mel I lIrQlt OnveS-- C/o 151"0'3 '

In This Issue

GEOLOGIC REMOTE SENSING 194

PLACER MINING CONFERENCE _ ' ' 194

PREPARATION AND USEOF EARTHOUAKE PLANNING SCENARIOS 195

MODIFIED MERCALLIINTENSITY SCALE 203

EARTHOUAKE PLANNING SCENARIO FOR THE

SAN DIEGO·TIJUANA AREA . 204

MARINE MINING 2000-APAIL 5·10. 1992 211

EARTHQUAKE BIBLIOGRAPHY 212

DMG RELEASE

SR 162. MINERAL LAND CLASSIFICATION-SAN LUISOBISPQ-

SANTA BARBARA P·C REGION......... .. ,214

BOOK REviEWS..... . 215

STATEMENT OF OWNERSHIP 215

MAIL OADEA FOAM 215

CALIFORNIA GEOLOGY SUBSCRIPTION FORM 216

COVER PHOTO: Loma Pneta earthquake damage. 1989Side VIew ot support column tallure and collapsed upper deCkot the Cypress Viaduct. t- 880. Oakland, California, The 7.1magnitude earthquake's epicenter was about 60 miles to thesouth PholobyHowardG Wilshire. U.S GeologICa/Survey,

Geologic Remote Sensing

"The Erwlronmencal Research Institute of Michigan is sponsoring the NmthThematic Conference on Geologic Remote Sensing; Exploration. Environ·ment. and EngUleeling_ The conference wUI be held on February 11.

1993 in Pasadena. California

For infonnatlOn. contact:

Nancy J WallmanERIM

PO Box 134001Ann Arbcw. MI 48113-3234313·994-1200. ext: 3234'

Placer Mining Conference

The 9th Annual Dredging & Placer Mining Conference & Short Courseon New Technology for?\acer Land Reclamatoo Planning wiD be hekl at

John Ascuaga's Nugget. Sparks. evada on May 17·20. 1992

For infonnation. contact,

Dr Yung Sam Kim orConference DirectorNevada Institute of TechnologyP.O_ Box 8894 Campus StationReno. NV 89507702-6734466

So'• ..... " 0 0 0 1 * ' " ~ S l ~ . - d Ls . r . d . - c r - .__ ~ a IllCALFORNlAGEOlOGYP 0 1loJr2llllOS-- CAlliYI22SlllO

September 1991NoIume 44 Number 9

CGEQA 44 (9) 193·216(1991)

,.. CAUfORNIA GEOlOGY SEPTEMBER 1991

Dr Philip M Bennett

Program DirectorDepartment of EngineeringProfessional DevelopmentUniveTSiry ofWisconsin. Madison

432 N Lake StreetMadison. WI 53706

608-263-4705·....



Preparation and Use of

Earthquake Planning ScenariosBy

GLENN BORCHARDTDivision of Mines and Geology

Figure I. Areas of DMG earthquake planning scenariOS: (1) Special Publication 60:

Earthquake planning scenario for a magnilude 8.3 earthquake on the San Andreas faultin southern California: (2) Special Publicafion 61: Earthquake planning scenario for a

magl1llude 8.3 earthquake on the San Andreas fault In the San Francisco Bay area; (3)Special Publication 78: Earthquake planning scenario lor a magnitude 7,5 earthquake on

the Hayward fault zone In the San FranCISCO Bay area: (4) Special Publication 99:

Planning scenario for a major earthquake on the Newport-Inglewood fault zone: (5)Special Publication 100: Planning scenariO for a major earthquake. San Diego-Tijuanametropolitan area.

PREPARATION

One practical and effective methoo is

to develop earthquake planning scenarios,hypothetical yet realistic assessments oflifeline performance for particular earth

quakes. Scientific- and engineering-basedearthquake planning scenarios are

important tools for planners because:(1) they approximate the effects of

earthquakes on lifelines: (2) they provide

important insight for use in earthquake

preparedness planning by emergencyresponse agencies and for law enforce

ment. fire fighting, medicaL and searchand-rescue services; and (3) they are used

in response exercises which simulate

emergency decision-making.

Development of an earthquake scenariofor emergency planning in a specific area

incorporates vast amounts of data from

various disciplines. The ability of a

lifeline structure to withstand theeffects of earthquake shaking,

fault rupture, liquefaction.landsliding, and associ

ated ground failurelargely depends on the

site geology and the

intensity of earthquakeshaking, as well as the

design and engineering

characteristics of thestructure,

N

\

Thus much of the damage to lifelines

caused by the magnitude 7.1 Lorna Prietaearthquake of October 1989 was

expected {Photos 1-4 and 7-8) and much

was not (Photos 5-6). The knowledgegained from each earthquake helps us

prepare for the next. How should we

organize suchhard-won

information?

How shouldwe put it into

action?

Dr. Glenn Borchardt is a contributing author01 four published Division of Mines andGeology earthquake planning scenarios. Heis a recognized expert In the determination

of amount and age of faull displacement

through interpretation of soilcharaclerislics ...edilor.

Each earthquake teaches us a lesson.pointing out with stark realism the

vulnerabilities of the infrastructure.

The infrastructure consists of "life

lines, M critical public facilities such ashighways, bridges. railroads, airports,

hospitals, marine installations. electrical

transmission systems. and pipelines for

water. natural gas and other petroleumproducts. [f we could predict which

lifelines will survive, we could prepareemergency plans to cope with those thatwill not. Search and rescue effortsimplemented during the critical first hours

will be smoother if we have some idea ofwhat to expect.

INTRODUCTION

C alifomians can expect

the nexl fev.. decades toproduce several major earthquakes in

large urban areas along the San Andreasfault system (VJGCEP, 1990). Destructive

as these events may be. there arenumerous ways to reduce their effects.

Slate residents have learned to build with

weed and steel instead of stone or bricks.

They boh their houses to foundations andtheir bookshelves 10 walls. Public agencies

are also preparing lor the inevitable.

Advanced planning by State and local

agencies will be critical in reducing thedeath. injury, and destruction.

CALIFORNIAGEOLOGY SEPTEMBER 1991 '95



Photo 2. Close·up of damage in Photo 1. Photo byaufhor

..

Earthquake SCenano Selecllon

The first phase of scenario development includes choosing an

earthquake-prone urban area based on its earthquake history

(Toppozada and others. 1986: WGCEP. 1990). Although there

is extensive historic documentation of earthquakes in California

during the past 200 years. additional data are required to selecta likely event. Paleoseismology. a recently developed branch of

seismology. includes various methods of investigaling lhe

movement along major fault zones over geologic time. Fault slip

rates. the amOWlt of displacemenl from specific earthquake

events. and the recurrence interval of earthquakes have been

detennined for some fault segments in Califomia.

PHASE I: PREPARATION OF THE SEISMIC INTENSITY

DISTRIBUTION MAP

.....-..

"- . ...

. :1'- \ .... ' ...:- ., -

.... . ' . ~ '-...,, ' •

• , • ' .•, ,- ,

. '., - ••,

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, '

. . PhOIO I. Lique'ac!lon damage to railroad tracks due to lateralspreadmg at the Port of Oakland. Damage was caused byshaking 'rom the Lorna Prieta earthquake. Photo by author.

DMG Scenarios

Five scenarios have been published by the Division of Mines

and Geology (DMGI for expected ma}oT earthquakes in denselyurbanized regions of California (rlgure l) (Davis and others.

1982a. 1982b; Steinbrugge and others. 1987: Toppozada and

others. 1988: Reichle and others. 1990). Each DMG scenario

includes maps showing the expected distribution of earthquake

damage to lifeline facl1illes based on seismology. geology. andengineering considerations. The two phases 01 the development

and preparation of a scenario are described below.

There are two phases in the development of an earthquake

planning scenario. Phase I is the preparation of a Seismic

Intensity Distribution (5[0) map showing the relative degree of

shaking and the areas of ground breakage. Phase lJ is the

preparation of lifeline maps annotated 10 show the hypothetical

status of the infrastructure dUring the first 3 days after theearthquake. Only 3 days are addressed because the effectiveness

of search-and-rescue operations diminishes after a day or two.

Inevitably. postdisaster reality supplants predisaster hypothesis

as alternative lifelines become established and well-known.

'"CALIFORNIA GEOlOGY SEPTEMBER 1991



Photo 3. Collapsed porIJOfI 01 State HJghway 101 over Struve Slough, PaJ3ro Valley. nearWatsonville. santa Cruz County. Damage was caused by strong ground shaking andliquelaetlon oj over deposIts dunng the Loma Pneta earthquake. Photo by DaVIdMontgomery.

1836. In comparison. the magnitude 71L..oma Prieta earthcf,Jake resulted in 6.5feet of slip in 1989 (P\afker and GalJo-

woy.19891.

Developing SID Maps

Once the location and magninde of aseismic event are decided. a SID map is

prepared. Planning areas. usuallycentered on the fault. include the densestpopulation and the most significantlifelines. If a major earthquake occurred

previously in the scenario area. its

characteristics are incorporated into thestudy. If no events of equivalent magni-

tude have occurred in the area. datafrom other areas are used to choose the

fault rupture length and amount of

surface displacement. For example. amagnitude 7.0 event typically causes up

to 3 feet of ground displacement along afauh segment over a distance of at least20 miles.

In his classic sndy. Sieh (1984) was

able 10 dale offset peat and sediment

layers. obtaining a detailed record of the

last dozen events on the southern San

Andreas fauh. Magnitude 8 events. likethe 1857 Fan Tejon eaTttxtuake. seem tooccur at intervals of 145± 8 years. Otherfaults. particularly those in the eastern

part of the State. have event recurrenceintervals that are ten times longer. For

example. investigations of offset soils and

volcanic ash along the Honey Lake fault

in northeastern California showed that

only four magnitude 7 events occurredthere dUring the last 7.800 years (Wills

and Borchardt. 1990).

Even where fine stratigraphic detail isunavailable. infonnalion about the slip

rate and relative movement along fauhs

over geologic rime can sometimes bedetermined. For example. cooperative

studies by Division of Mines and <::iedogyand U.S. GeoklgicaI Survey scientists

show that the H ~ r d fauh had a sliprate of between 5.5 and 9mmIyr duringthe last 9.000 years (Borchardt and oth-ers. 1987: Borchardt. 1988a: 1988b:UenkaemperandBorchardt.I991).

These investigations infer that up to 4.6

feet of strain may have developed at

depth along the northern part of the fault

since the last major earthquake there in

Photo 4. Close-up 01 damage in Photo 3 shoWing columnar supports pierCing the highway.Photo by MIChael Manson.

CALIFORNIAGEOLOGY SEPTEMBER 1991

",



Photo 5. Collapsed upper section of the San Francisco-Oak-land BayBridge between Verba Buena Island and Oak-land. The collapsecaused the death of one person. The canfilever design wasengineered to have the upper section rest on vertical steel suppontowers. During the tremor. one such tower swayed, snapped off the2·inch bolts that anached the upper bridge span. and allowed a 50·foot section to crash onlO the lower deck-.It took- 1 month to restore service 10 thisimportant bridge. Photo by Howard Wilshire,

courtesy of the U.S. Geological Survey.

Unfortunately. the estimation of

regional patterns of seismic intensity is

no t yet as accurate as scientists and engi·neers would l ike. Each type of structure

responds in a unique way to seismic mo

tion. At present. i t is not practical to de

velop the necessary intensity scale fo reach type. Nevertheless. researchers have

found that the Modified Mercalli Intensity

(MMI) scale is an effective 1001 for gener

alizing earthquake intensity at any loca

tion (see page 203).

Developing a SID map begins with a computer-generated

isoseismal contour map centered on the scenario fault rupture

(Evemden and Thomson. 1985). Each contour on an isoseismal

map shows the area that would undergo the same amount of

earthquake shaking intensity. Assuming perfectly uniform

bedrock geology. shaking will decrease with distance. Successive

contours from the proposed fault rupture zone indicate areas

that hypothetically undergo progressively less shaking.

Geologic Map

An accurate geologic map is essential to scenario prepara

tion. The geology of an area is never unifonn. For most

structures. earthquake damage is usually greater on soft sedi

ments than on hard bedrock. In developing an intensi ty map. it

is estimated that structures on young unconsolidated sediments.

lo r example. will incur damage described by intensities two units

ROCK TYPE AND CORRECTION FACTORS

FOR SHAKING INTENSITY TABLE

Rock types and their respective correction factors illustratehow the underlying geology affects earthquake shaking. Thesecorrection foctors are added to seismic intensities calculated for

well·consoiidated unweathered bedrock

Correction Factor for

Rock Type Seismic Intensity

lnstrusive igneous and metamorphic rocks 0.0Volcanic rocks 0.3MiOCene nonmarine sediments 1.3Miocene maline sediments 1.5P1ioce11€ ond Pleistocene sediments 18

Holocene sediments 2.0

Scenario SID maps display intensity,

fault rupture. and ground failure informa

tion. Some features are developed

especially fo r the scenario and others

depend on earlier studies.

Photo 6. Collapsed steel rebar and concrete column of the Cypress 1·880 treeway structure.Oak-land. California. A t-mile length of thiS double·decked reinforced·concrete Viaductcollapsed onto commuter traffic k-illing 41 and mjuring many others during the Loma Prietaearthquake. The failed column in the foreground supported the top deck. Built in the 1950s.the columns had venical steel remforclng rods but lacked the spiral reinforcing rods used inmodern construction. Photo by Michael Rymer. courtesy of the U.S. Geological Survey.

",CALIFORNIAGEOLOGY SEPTEMBER 1991



o 5

VIII+ _ IX

Newpon Beach N

a CEA

ClF1C

p I '

IVIII-IVII

Figure 2. seismIC intensity distnbution predicted fOf a magnitude 7 earthquake on the Newport-Inglewood lau1l, southern California.

Modified from Toppozada and others (1988).

higher than those on intrusive ingneous rocks (see table. p.1981.

TI1erefore. within 5 miles of the fault rupture of a magnitude 7earthquake. the MMI ;s estimated to be VII in well-consolklatedbedrock and IX in soft sediments.

The isoseismal contour map is typically developed by DMG ata scale of 1:100.000. A composite geologic map al this scale is

used to modify the isoseismal contour map to account for

differences in the geology. The completed SID map (P19ure 2)also shows areas likely to suffer permanent ground breakage

such as fault rupture, liquefaction. and landslides. 1llese areas

will produce MMls up to Xli that cannot be predicted by thecomputer program that generates the isoseismaJ contour map.

Fault Rupture: The scenario postulates a specific rupturealong mapped fault traces shown on the l:24,OOQ-scale maps

that are produced as part of DMGs Alquist-Priolo Special

Studies Zones fault mapping project (Hart. 1988).

liquefaction: Three conditions are present in areas whereliquefaction is shown on scenariomaps: (1) presence of a highwater table; (2) layers of loose sand: and (3) earthquake shaking

of sufficient intensity and duration. Flat·lying areas havingshaking intensities greater than VI generally satisfy the third

criterion. Alluvium with groundwater within 10 feet of thesurface is highly susceptible to liquefaction, while alluvium withgroundwater deeper than 30 feet below the surface is not.

Landslides: Because few existing maps delineate areassub.iect to seismically induced 1ancIsiiding (SILJ. maps showingareas of general susceptibility to climatically. as well asseismically. induced landslides are used in scenario preparation.Where landslide maps are not available. topographic maps are

Photo 7. Damage trom liquefaction and slumping of fine·grained, well-sorted sand fill at the PM of Oakland.Photo by David Montgomery.

CALIFORNIA GEOLOGY SEPTEMSER 199\

'"



Anahe1ma

- - Major TransmiSSion Routeso Transmission §>ubstatlon

o Power Plant

Damage

oShut down

o 1-2days

• Shut down more• than 3 days

ELECTRICAL POWER FACILITIES

o

Pasadena

o

olos Angeles

"I

1o , , " , . - i 5 ~ M l l E SSCALE 111111111111I11111 NEWPORT - INGLEWOOD

FAULTZQNE

CAUFOANIA DEPARTMENTOF CONSERVATIONDIVISION OF MINES ANDGEOlOOY

PHASE II: ASSESSMENT OF THEEFFECTS OF THE DISASTER ON

LIFELINES

The second phase of scenariodevelopment involves the preparation ofseparate maps showing the likely effectsof the event on each significant type of

lifeline. This phase involves: (I ) comparing the SID map with maps showing

lifelines: (2) assessing the damage

expected at the vulnerable points ofspecific lifelines: and (3) projecting theperformance and operational use of each

lifeline system during the first 3 daysfollowing an earthquake.

For example. in DMGs southernCalifornia Newport-Inglewood earthquakeplanning scenario. some electrical

facilities are expected to be inoperative(or at least 3 days following a majorearthquake (Figure 3). These facilities arein areas of high liquefaction potential

within the MMIIX region of the SID map.Certain types of modem electricalsubstations are highly vulnerable 10

shaking even when liquefaction does 001

occur (Photos 9 and 10).

used to delineate areas of weak rockhaving slopes greater than 30 percent.Future scenarios will subdivide SIL into atleast two categories: falls and slides. Falls

dominate on slopes greater than 70percent. whereas slides dominate onslopes between 30 and 70 percent. The

distinction is important because fallsdamage lifelines from above and slidesdamage them from below.

Lifeline Damage Assessments

Figure 3. Predicted e!lact on electrical facilities following a major earthquake onthe NewporHnglewood taull zone. Modified from TOpPOzada andolhers (1988).

Scenario damage assessments rely onobservations of damage to similar lifelinesexposed to comparable shaking orground breakage during previousearthquakes. Lifeline repair times are alsoestimated from previous experience.

Structural engineers develop thedamage estimates in collaboration with

DMG earth scientists. The managers oflifelines included in the scenario are asked

to review the estimates using theirexpertise and knowledge of specific

lifelines. The combined background andexperience of professionals from variousdisciplines significantly augment ourunderstanding of earthquake damage

expected for facilities.

SCENARIO USES

Earthquake planning scenarios aredesigned to give a realistic image of ananticipated earthquake. They teach us an

important lesson: some lifeline facilitieswill be damaged and others will not. By

pinpointing the areas where extensivedamage is likely, scenarios highlight

locations where lifeline facililies needspecial anenlion from emergency

planners. public offjcials. and engineers.

Scenarios identify locations v.mere

lifelines are vulnerable so that emergencyoperations can cope with probable lifeline

failure. Emergency plans develop contingencies based on important facts brought

to tight in the scenarios.

The scenarios show that major earth

quakes in densely populated areas produceabundant synergistic effects. Lifelinemanagersmust be aware of v.>eaknesseswithin their CMIIl systems. and know how

damage to Olher lifelines will impact theirsystems. Pre-earthquake planning can be

especially effecttve where two or more

lifelines interact (such as a City water main.a State highway. and a private pov.!er line),

causing normal jurisdictional lines tobecome obscure.

200CALIFORNIAGEOLOGY SEPTEMBER 1991



Scenarios have stimulated site-specific

geotechnical revie\.vs of existing Meline

facilities, For example, Berryman Resen.-oir,

bJilt in the Haoyward fault lOIle, was re

examined by geotechnical 8Tl31neers after its

failtre was hypothesized in theHayward

""""" . H<Mng tho _«hn<aJ

review. Berryman Resen.uir's I-.;potheticaIfailure no longer can be used for FUJXlSeS

of disaster response planning.

Another example of action taken partlyas a result of the pre-eanhquake planning

promp(ed by the scenarios is the deaberatekJ.vering of the water table in the dly of SanBernardino. It has been b.vered to 10 feel

bOOw the surl"", and \ong-rnnge """ 'invo/ve k:Jo.vering it pennanently to 30 feetbOOw the surl"",- the _ boyood um<h

l;q.,eloction. ~ ~

Photo 9. Damaged electrical insulators caused by ground shakingby the magnitude 5.9 North Palm Springs earthquake 0' July 8,1986, The tall porcelaln·glass insulators with lO-foot·high percheswere constructed With very linle lateral support and most add·onearthquake braces 'ailed, Over $3.5 million in damage was causedat the Southern California Edison Company's Devers substation,Coachella Valley. The Devers substalion is within 1 mile ot theepicenter o! lhe earthquake thaI occurred on the San Andreas faull.Photo by author,

Photo 10. Damaged Devers substation insulators, Transrrussion ..

substations are particularly vulnerable to earthquake shaking.However, studies are underway to improve the seismic performance01 massive trans'ormers and high·voltageporcelain insulators atsubstations, The unexpected heavy damage 10 electricallranstorm·ers and insulators at the Devers substation urged improvements in

earthquake-Iesistant design 'or handling high voltage requirements.Although such damage is unlortunate, il prOVides valuable lessonsfor reevalua\lllg the design al'ld construction ot other electricalsubstations Iocaled near active tauIts. Photo byau/hor.

"' / '

v

•

Photo 8. Landslide blocking the northbound lanes of Highway 17 through the Santa Cruz "These hypothetical scenarios provideMountaJns. Photo by Tom Holzer, courtesy of the U.S. GeoJogical Survey. examples of typical problems, It is up to

lifeline managers to open communication links and establish

polit ical arrangements that wil l facil itate a swift arK! smooth

response. Well-rehearsed managers and personnel can save

many lives during the critical first hours after an earthquake.

CALIFORNIA GEOLOGY SEPTEMBER 1991

'"



DMG Earthquake Planning Scenarios

CONCLUSIONS

The data presented in eanhquake

planning scenarios assist planners andemergency response agencies in rOOucing

California earthcpJake losses. Scenarios

contain SID maps that show how various

geologic units respco:i to eanhquake

" " " " " and ground breakage. Map;sh<;:r.virg critical ~ f e l i n e SIfilel1lS are superim-posed on a SID map to highlight facilities

likely to trdergo the IT'lC6t damage in the

_ "' ' ' ' ' ' ' ' ' ' ' ' ' . klenti""" "1_that v..'iII be unusable follolMng a major

hclp; and """""" ' "response agencies Jessen the impact.

Scenarios stimulate geotechnical review.>and etlCOUl'CIge the upgrading of certaincritical structures. In crl:Iition to providing afocus lor ernergeT"Cy planners. earthcp...lake

planning scenarios are becoming an

important tool for infonning the p.hIic of",ticipotro d o m a g ; " , ~ .

ACKNOWLEDGMENTS

Numerous scientists and engineers as wellas hurdreds of piliic ofOCials have contrib-uted to these scenarios. This methcxI of

preparing them is the cubnination of k:Jeas

firs!: advanced by J.F. Davis, California StateGedogist. The manuscript was revilaved byT.R. T ~ M.S._. and J.F.

Davis of the Qio...;sion of Mines and Geology.

REFERENCES

Borchardt. Glenn. editor. 1988a. Soildevelopment and displacement along lheHayward fault: Fremont, California:DIVISIon of Mines and Geology Open-File

Report DMGQFR 88-12. Final technical

report for the U.S. Geological SurveyNational Earthquake Hazards Program,v. 1, 124 p.

Borchardt, Glenn, editor, 1988b, Soil

development and displacement along the

Hayward fault: Point Pinole. California:Division of Mines and Geology Open File

Report DMGQFR 88-13, Final technICal

report for the U.S. Geological SurveyNatIonal Earthquake Hazards Reduction

Program, v. 2. 233 p.

Borchardt. Glenn. Uenkaemper. J.J.. andSchwartz. D.P., 1987, Holocene slip rateof the Hayward fault at Fremont,

CalifornIa: EOS, Transactions 01 the

Amencan Geophysical Union. v. 68,no. 44, p. 1506.

Davis. J.F .. Bennett, J.H .. Borchardt, Glenn,

Kahle, J.E., Rice, S.J., and Sliva. M.A.,

1982a. Earthquake plannlf'lg scenario fora magnitude 8.3 earthquake on the SanAndreas fault in southern California:California DiviSion of Mines and Geology

SpecIal Publication 50, 128 p.

DaVIS. J.F.. Bennett. JH .. Borchardt, Glenn.

Kahle, J.E., Rice. S.J. and Silva. M A.,1982b. Earthquake plannlf'lg scenano fora magnitude 8.3 earthquake on the SanAndreas fault in the San Franosco Bay

area: California Division of Mines andGeology Special Publication 61, 160 p.

Evernden, J.F .. and Thomson, J.M" 1985.

PredICting seismIC Intensi\les. in Ziony.J.I.. editOf, Evaluating earthquakehazards In the Los Angeles region: An

earth science perspec\IYe: U.S Geologl'

cal Survey ProfeSSional Paper 1360.p,151·202.

Hart. E.W.. 1988. Faull-rupture hazard zonesin Califorma (revised): DIVision of Mmes

and Geology Special Publication 42. 24 p.

Lienkaemper. J.J.. and Borchardl, Glenn,1991. Holocene slip rate of the Hayward

fault at Union CUy, California: GeologicalSociety 01 America Program With

Abstracts. Cordilleran SeclJon. v 23.no. 2. p.73.

Plalker. G.. and Galloway, J.P.. editors.

1989. Lessons learned trom the LomaPriela. California earthquake 01 October17. 1989: U.S. Geological Survey Circular1045.48 p.

Reichle. M.S.. Kahle. J.E.. Atkinson. T.G..

Johnson. E.H.. Olson, A.A.. Lagono. H.J..StelObfugge, K.V., Cluff, L.S.. Haney.

T,P., and Powers, J.E., 1990. Planning

scenario for a malor earthquake SanDiegO-Tijuana metropolitan area: DiviSionof Mmes and Geology Special Publication

100. 182p

Ave Division of Mmes and Geologyearthquake planning scenalio5 are availablefor purchar.e and prepaid mail order at DMG

ollices in Sacramento. San Francisco, andLos Angeles. AD prlces include shipping and

handbng. Make checks payable to, Divisioo

of Mu'les and Geology. Send to:

Division of Mil'leS andGeologyPO , Box 2980

Sacramento. CA 95812-2980

SPECIAL Pl/BUCATlQN 60: Earth-

quake planmng scenario for a magnitude83 earthquake on the San Andreas fault insouthem California ByJ,F Davis. JH

Bennen. Glenn Borchardt. JE Kahle. SJ

Rice.andMA Silv<! 1982. 128p.$1200.

SPECIAL PUBUCATION 61 Earth

quake planning scenario lor a magnitude8.3 earthquake on the S<m Andreas fault Inthe San Francisco Bay area By J. F. Davis,

J.H Bennett. Glenn Borchardt. J E. Kahle,S.J. RICe. andMA Silva 1982.160 p.

$12.00

Sleh. K.E .. 1984, Lateral ollsets and revIsed

dates of large prehistoric earthquakes atPallet Creek, California: Journal of

Geophysical Research. v. 89, p. 7641·7670.

Sleinbrugge. K.V., Bennett, J.H.. Lagono.

H.J.. DaVIS. J.F., Borchardt. Glenn.

Toppozada. TR. Oegenkolb. H.J..

Laverty, G.L" and McCarty, J.E" 1987.Earthquake planning scenario lor a

magnitude 7.5 earthquake on theHayward fault in the San Francisco Bayarea: California DIVISion of Mines and

Geology Special PublicatIon 78, 243 p.

Toppozada. T.R.. Benrl8tt. J.H.. Borchardt,Glenn. saul, A., DaVIS, J.F., Johnson,C.B.. Lagorio, H.J.. and Steinbrugge, K.V.. 1988. Planning scenario for a majOrearthquake on the Newport-Inglewood

fault zone: Division of Mines andGeology Special Publication 99. 207 p.

Toppozada. T.A.. Real, CR. and Par1<.e.

D.L. 1986, Earthquake hlslory of

California, CatifOfnla Geology v. 39.

no. 2. p. 27-33.WGCEP (Working Group on California

Earthquake PrObabilities). 1990.Probabilities of large earthquakes

occurnng in the San FrancISCO Bayregion. California: U.S. GeologICal

Survey Circular 1053, 51 p.

Wills. C.J .. and Borchardt, Glenn, 1990.

Holocene slip rate and earthquakerecurrence on the Honey Lake fault

zone. northeastern California: EOS

Transactions. American GeophysicalUniOn. v. 71, no. 43, p. 1608:-'

SPECIAL PUBUCAllON 78: Eanh

quake ~ n n i n g scenario lor a magnitude

7.5 earthquake on the Hayv.;ard fault zone

in the S<m Francisco Bay area. By K VSteinbngge. J.H Bennett. H.J.I...agofio.

JF . Davis. Glenn Borchardt. and TRToppozada, 1987 242 p. $30.00.

SPECIAL PUBUCAllON 99, Planningscenario for a major earthquake on the

Newpon-lnglev..'OOd fault zone. ByTRToppoZ<tda. JH Bennett. Glenn

Borchardt. R Saul. and J.E Davis1988

200 p. $22 00,

SPECIAL PUBUCAnON 100

P1<lnning sc('nario for a major earthquake.S<m Diego-lljuana metropolitan ar('a By

MS, Reichle, J E. Kahle. TG. Atkinson.

EH Johnson. RA Olson. H.J.Lagotio.

KV Steinbrugge. LS ChJff. TP. Haney,

and J,E. PcMoers. 1990. 182 p, $22.00. )0.'

202 CALIFORNIA GEOLOGV SEPTEMBER 199\



MODIFIED MERCALLI INTENSITY SCALE

The severity of an earthquake is described by the Modified Mercalli Intensity scaJe introduced in 1931 by American

seismologists Harry Wcxxl and Frank Neumann. They established 12 categories of intensity. The follO\.ving is a con-

densed version-

Wood. H.O.• and Neumann, Frank, 1931, ModIfied Mercalii IntenSItyscale of 1931: Bulletin of the Seismological Society of America,v.20, p, 277·283.

Xli Total damage. Waves seen on ground surfaces. lJnesof sight and \evel are distorted. Objects thrown intothe air.">/'

IT

III

IV

v

VI

VlI

Not felt except by a very few Wlder favorable

circumstances.

Felt only by a few persons at rest. especially on the

upper floors of buildings. Suspended ob.iecls may

swing.

Felt quite noticeably indoors, especially on upper

floors of buildings. but not necessarily recognized as

an earthquake. Standing cars may rock slightly.Vibration similar to that of a paSSing truck.

If during the day, felt indoors by many: outdoors by

lew. If at night, few awakened Dishes. windows.and doors rattle. walls creak. A sensation such as a

heavy truck striking the building. Standing cars rock

noticeably.

Felt by nearly everyone. many awakened. Somedishes and windol.vs broken. some plaster cracked.

unstable objects overturned. Disturbance of trees.poles. and other taU objects. Pendulum clocks may

stop.

Felt by aU. many people run outdoors. Fallen

plaster. minor chimney damage. Movement ofm<X!erately heavy fumiture.

Everybody runs outdoors. Damage negligible in

buildings of good design and construction. slight tomoderate in well-built ordinary structures: consider-able in p<Xlrly built or badly designed structures,

Some chimneys broken. Noticed by persons driving

"'"

C ~ L 1 F O R N I A G E O L O G V

VIII

IX

X

XI

Damage slight in specially designed structures:

considerable in ordinary substantial buikfings. Panelwalls thrOVJl1 OUt of frame structures. Chimneys.factory stacks. monuments, walls. and columns fall.

Heavy furniture overturned and damaged. Changes in\Nell water. Sand and mud ejected in small amounts.Persons driving cars are disturbed.

Damage conslderable in specially designed structures:

v.oeU-designed frame structures thrown ou t of plumb:great damage in substantial buildings. which suffer

partial collapse. Buildings shifted off foundations.ground noticeably cracked, underground pipes

broken.

Some well-built Vo'OClden structures destroyed. mostmasonry structures destroyed. foundations ruined.

ground badly cracked. Rails bent. Considerablelandslides from steep slopes and river banks. Watersplashed over banks. Shifted sand and mud.

Few. if any. masonry structures remain standing.

Bridges destroyed. Broad fissures in ground. Underground pipes out of service Earth slumps and land

slips in soft ground. Rails bent greatly,

SEPTEMBER 1991 203



EARTHQUAKE PLANNING SCENARIOFor the San Diego-Tijuana Area

By

MICHAEL REICHLE

Division 01 Mines and Geology

----_.

.E I Cajon

CA:'I$

HIGH LIQUEFACTION

POTENTIAL

SEISMIC INTENSITY

DISTRIBUTION

INTENSITY (MM) []]!]

mJ

.~ "

\\

~ ••.....\

\oo

'".,....

•0 5 MIlES, ,

..."

o

Mission

80y

Figure 1. Seismic intensity diSlributlon. . .

ThIs is a summary of the DIvISIOn 01 Minesand Geology Special Publication 100.Planning SCenario for a Major Earthquake.San Diego·Tijuana Metropolitan Area,published last year. A workshop was held inDecember 1990 lor emergency responseplanners for the city and county of San Diegoand lor private industry and utilities. Theworkshop prOVIde<:! an opportUnity to diSCUSSthe Intended uses and potenllal misuses ofthe scenano and to examine its conlents In

detall The vanous officials thaI attended areworking wIth others and incorporating what

they learned Into thelf p1anrung efforts Inorder 10 reduce losses In the event of adestructJVe earthquake....editor.

INTRODUCTION

H istoricaUy. the San Diego area hasbeen rclatively free from the effects

of damaging earthcf.Jakes. Earthquakesoccurring offshore and beneath themountains and deserts to the east haveinflicted only minor damage on SanDiego. Stooies by Toppozada and others(1981) and Toppozada and Parke (1982)

list 13 eanhquakes that inflicted at leastMcx!ified MercaUi Intensity (MMi) VI onSan Diego since 1800 (see page 203).

It cannol be assumed. however. that thishistoric quiescence will continue indefi

nitely. The Rose Canyon fault zone (whichincludes the Silver Strand fault). the LaNadon fault. the Coronado Bank fault.

the Vallecitos fault (San Miguel fault zone).

and myriad smaIJer faults pass through. orck>se to. the San Diego metropolitan area.

Of these. the Rose Canyon is probablythe most hazardous. foDowed by the

ltighly """'" Comn"do Bank ard the San

Miguel fault zone.

The seismic hazard in the San Diego };>

area is diffICult to quantify. Extensive ~ Q \ £cultural development and a lack of well-

dated Quaternary deposits have limitedboth the quantity and quality of the data

relating to the more recent geologic




history of the area's faults. Criticalparameters. such as geologic rate andsense of movement along local faults.recurrence timeS of damaging earthquakes. and recency of faulting are TlOI

\l.'eD-knoY.n. The recent evidence ofearthquake aeti\ity on the Rose Canyonfault within the last several thousand yearsIl-md-..n <rod ome... 19901__ , thaI

It wcUd be prudent to asstI1lli!: thatdamaging eanhquakes oouId OCCll' in the

San Otego area at al'1!l- time

To assist kxaI and State emergencyresponse planners in their preparahon for

a d a . " T l i l I g i r g ~ . theDivision ofMmes and Geology has pub.ished anearthquake p0rming scenan:> for the San

"""'" area (ReKhIe and ome... 19901This information is intended for thosev.OO have responsIbUIl:es for emergencyresponse. and 10 facilltale both kx:aI andinternat)onal efforts 10 prepare for such

an occurr6lCe· The scenario does noIpredlct detailed paUem5 of damage lhal

win fobt the occurrence of the postulated e a ~ k e An assessment of thedegree and Iypes of damage [0 exJ$ling

lifelines and Olhel'" structures is placed in aregiooal context for ge'lCJ'al responsepLannmg purposes The damage

assessments contained in the

scenario are intended for emer-

gency planning purposes only, andar e not to be construed as sitespecific engineering evaluations.

The data discussed in the scenarioref1ec:t condItions in San DiegO in themid-1980s. A n a ~ were conductedwith the cooperation of the variouslifeline opercuors This article summarizes

the scenano

THE SCENARIO EARTHOUAKE

The ~ e M r i o ~ r i b e s lhe regionalpanem of shakirg intensity. groundfo!llilure. lind impllCts on lifelino of al1"la9nitude 6.8 earthqw.ke on the SilverStrand fault. which lies immediatelyoffshore of the San Diego waterfroot(Hgurc I). PcrOOp5 hll-zord0u5lllUlts

exist. and could have been used for arl29k:lna1 planning scenario. H ~ this

scenario ",'as devdoped for a particularuw' inlQmationai respooso p;anning.assunmg an earthquake tnfliets signifICantdamage on both IN San Diego andT rnetroPOltan areas. HOWC\<er.

damage assessments of the lX)Stu1al:edearthquake are genercilly confinod 10 U.S.

facilities and lifelines.

For the scenano earthquahe. surfacefaultl\lplUu (rJgUl"c 1) el'lends from the

douinlCJI,A." San Dego area approximately24 m:Ics along the ~ to !he MlUlh.

tenninatmg approximalely 16 miles southof the intcmalionaf bordeT. Potentiallydamagmg shaking contnues 'or 10 to 15scc:onds .....'ithin 12 miles of the ';:auk.Frecpml af:ershocks cootlJVJl!: for several

induding events of magnitude 50

"'-Areas subtect to shaking of MMllX(F"J9UTe 1). indude those areM of re«mt

(l-Iokxene) alIuvilJl1 and amfria1 filltN:> TIa.Lana River Valley

California portion) and dou."lOlA-'n San

""""'ICornnado

I\rros subJect 10 shiWng ofMMI VlII

extend from below Rosanto 10 Dei Maralong the c ~ and as Iar as 23 mile,

hland for poorestground conditions.nlUition and the damage distributlom

from histoncal cnfomia earthquakessuggest that areas 01 firmer ground tsuchas Pt. Lama and Hillcrest) .....ill shakeolf!erQrlt[y than areas of rccent alluviumor fill (such as Mission Bay). Less damageYlould occur on firmer ground than on

looser ground evenlh0t9h

both lie WIthinthe area of intensity V111

Areas with high <;uscepllbilily to

hquefac:tion are also shown in Flgure ISecondarv ground fl'lilurp<; re<;uhing from

hquefaction are expected to be common.particUarly in areas of hydraulic fill inMission Bay. l..om3 Portal. and along themargins of San Diego Bay. Also. areas ofrecent aBlNium. particularly along m<erchannels. such as the western reaches ofMission Valley and the ll a Juana andOtay River valleys. wiD experience

moderate to 5e\ICre liquefaction effects.

S e i s m i c a ~ indu::ed lancbbdes pose anadditional threat in those geologicconditions lMlcfe both ancient andmodem slides have beenmapped. Area50.....nere 1andsI.des could pose particularprobkmls irrlJde the north sde ofMission Va1k!y. Mu-phy ean.,.oo. MISoledad. Torrey Phes Mesa. lhe canyonsof Otay Mesa. and portJoos of La Mesa

IMPACT ONTRANSPORTATION LIFELINES

MalOf F r e e w a ~ Routes

The maJOr conidors 01 highway traffic:in tho San Diego <)rca are illustrated . ,

FIgure 2 They incltde:

• Th-ee major north-south routes,Inllml.ates 5. 805. and 15

• T\\.'0 mapl' easl--\l,'eSt routes:1-8 and Highway 94

interstate highways 5 and 15 lead intothe area from the oorth. b1terstate 5Ieacb 10 the MexiCMt txxder on the southand pa!'JSCS ~ both Mission Bay and SanDiego Bay. Intersta:e 8 is the p r l m a r ~ ;access 10 points ea!t. Interstate 805provides an alernaliYe north-soulh

corridc>f to the area ea5I of 1-5 There areseveral akematNe surface streets whichc.1n be used 10 bypass sections of thefreeways. but prirnCYy access to thesecnon of the city \\.'eSl of 1-5 in theMission and San Diego Bay areas is

limited 10 a fe.v mlral corridors. Thereare sorre citymaintained bOOgesthese cntlcal corridors.

Damage 10 the freeway syslem in the

San Diego area will result primarily fromground failure due to liquefaction in areasof artlfloal fill and recent aDuvial deposits.

aTd also from failure of built-up embank-ments for road beds and onloff ramps.Interstate 5 will be dosed from BalboaAvenue on the north to Palm Avenue onthe south. Both 1-5 and old Route 101wlJI also be closed \\.here they cross eachof the coastal lagoons soulh ofOceanside.Illlen.tal\! hlylways 305. 15.MIl 8. Melhighways 163. 94. and 117 will be openexcept w h ~ l e they join 1-5. Long delayswi'l occur along Interstate 8 and Highway163. res.dting from dAln",ge 10 theil

interchange. The Coronado Bridge will becmed. I'tae5s to Coronado on Highloloay

75 along the Silver Strand wiD be severelyrestricled. Although:sornewhi:lt obslJUeted. ma;or routes intO and out of thegrrotcr San DIego are l I will be llVlllloble

However. emergency YChi:1e nansporIa-rion into and out of :he ITIOSI ~ v i I ydamaged areas along the coast fromPaciHc Beach to Imperial Beach Iolo;D be

hampered by closures of all main artene5

VJhere they cross areas 01 unstable

ground.

CALIFORNIA GEOLOGY St:.PTEcMBER '991



Military airports are:

Naval Air Station, Miramar

Naval Air Station, Nonh Island

Naval Air Station, lmpertal Beach

for automobiles (normally 16 of 24

primary inspection lanes aTe used). Trucktraffic is primarily handled at the Glay

border crossing.

The major commercial ail'JX>11S in theplanning area are sho<M1 in Figure 2.They are:

BuildingS at the border station win beseYeTety tJamagro. Unreinforced masonry

walls of the Old Pon of Entry Building wiDsuffer major structural damage or collapse

and the building will be evacuated. Forplanning purposes. the pedestrian bridge

that spans the trafflc laneswill beclamaged and out of service for 6 months.Loss of electric poIAIef from the San

IMgo e ;" & EJ.ctric Oxnpany ISDG&Ej\\liD occur. Emergency power generatorson the Site ""ill not function. Umite::i

power supply \\Iill not be reslored for 72

hou".

The San Ysidro Border Station VJiIi be

closed for at least 3 clays for all but emergency use because of severe damage tobuildings. restricted access problems due

to damaged freev.tay bridges, lack of

power and utility services. and kiss ofback-up emergency electric power.Damage assessment and clean-up willtake 10 days to complete at the site. afterwhich the border station VJili function at

50 percent capacity for 6 months and80 percent for 8 months before fulloperation is restore::i,

San Diego International

IUndOOgh P " ' ~ ITijuana International

{ c . n e . a JR_

Secondary domestic airpons inClude:

Brown Field

Gillespie Fiekl

McClelland - Palomar

Montgomery Reid

Oceanside Municipal

Ramona

_.. _..-_.,.----

Tijuana

Inri

~ B r o w n9 Field

The San Ysidra Border Station housesU.S. CUSloms. U.S. Irmnigralion. theDepartment of Agriculture. the U.S. Na"'YShore Patrol. the U.S. Drug EnforcementAgency. and the International Boundary

and Waler Commission. II is the principal

port of entry from Mexico for pedestrian

and automobile traffic. The stationpresently operates at 70 percent capacity

._---'SECONDARYAIRPORTS

MAJORCOMMERICAL

&. MlllTARYAIRPORTS

ImperialBeach

NAS

•• MILES, ,SCALE

HIGHWAYS AND AIRPORTS

oo

'".....

SaoDiegolnfl.

san DIegO Border CrQSSIng

1he border station at San Ysidro.California is the busiest port of entry in

the world. It operates in conjunction with

the recently constructed border station alOtay. located 5 mlles to the east. TIle

building and related facilities are main

tained by the General Servk:es Administration.

206 CALIfORNIA GEOlOGY SEPTEMBER 199\



Figufe 3. Electric power.

..---_ ..

ELECTRICAL POWER

TRANSMISSION LINES

_ 500 KILOVOLTS

_ 230-287 KILOVOLTS

..__.. 138 KILOVOLTS

• POWER PLANT

• MAJOR SUBSTATION

Railroads

Only the Atchison. Topeka. and SantaFe Railroad (ATSF) serves San Diego. TheSan Diego and Imperial Valley Railroad(SDM formerly extended from downtownSan Diego through Tijuana to EI Centro.

• TIJUANA

----_..---.--'-

• Imperial Beach

SAN DIEGO,.}

<, \ • National CtlV. /• • Chula I£ifta,--'

,,...~

\0::·.·.·.0:

•

\

o

"'""2-

•, MlLES, ,

"""

operations. Performance of the lifelinesystems for airport operations will becritical. The success of air operations will

depend more upon the availability of

electric power and fueL and the survivalof crilical buildings. than upon thecondition of the runways.

San Diego International Airport islocated 2 miles from the center of thedowntown business distlict. On its north.east. and west sides it is surrounded bydensely populated military. commercial.and residential development. Its south

skle faces San Diego Bay. It is owned and

operated by the San Diego Unified PortDistrict. This airport handles a p p r o x i ~mately I I million passengers per year.averaging 30.000 passengers per day.

Usually 50 commercial passenger planesare parked overnight at the airport.

Brown Aekl Municipal Airport. ov""ed

by the City of San Diego. is planning forintensive emergency use in the event thatUndbergh F'tekl is out of commission foran extended period. Brown Field is

located 18 miles by freeway south andeast of the central San Diego business

district. It is approximately 1·1/2 milesdirectly north of the Mexican border and

2 miles directly north of Tijuana Interna

tional Airport.

For planning purposes. San DiegoInternational Airport will be closed for allbut emergency operations for 2 weeksdue to liquefaction affecting runways.access. electric power supply. and the

East Terminal building. Accessibility byway of Harbor Drive and the overpass

entrance to the airport will be impaired

for 72 hours because of ground failure.Alternate access routes will have to be

developed.

8ectric power to the airport will be

unavailable for 10 days because of

damage due to ground failure along thefeeder line routes. Impaired electric

power will affect the pumping of aircraftfuel from underground storage tanks. Forplanning purposes. two of the fiwstorage tanks will be out of service so it

\l,111 be necessary to bring in fuel by tanktruck to fuel airplanes directly.

Four airports In the planning area

prO\lide the 5.000 feet of runway

necessary for the landing of C-130 andC·141 aircraft. Twe of the four. namelySan Diego International Airport andNaval Air Station. North Island are in

zones of heavy damage and potentialliquefaction. The other two (Brown Hekland avaf Air Station. Miramar) arelocated in areas not subject to liquefactionand where predicted shaking will produceminimal damage. [n general. only thesetwo can handle emergency response

CALIFORNIAGEOLOGY SEPTEMBER 1991



• Del Mar

o

"'"'""

•, 5 MllES, ,

~

WATER AND WASTE WATER

FACILITIES

__ MAJOR AOUEDUCT

- - - WASTE WATER PIPELINE

• WASTE WATER TREATMENT

• PUMP STATION

• EI CalOn

• LelT1Of'l Grove

\

···

S u p p ~ e s can be off-loaded at Oceansideor Escondido and trucked south. althoughtravel win be disrupted on major fr€€Ways

due to damaged bridges blocking through

traffic.

The San Diego and Imperial Valley

Railroad and the San Diego TTolley crossareas of high and very high liquefactionsusceptibility along San Diego Bay and in

the ria Juana River Valley. Roadbeddamage will prevent use 01 the Unes from

downtown San Diego to the international

border for about 3 weeks.

In additk>n to the liquefaction-inducedfailures. landslides along coastal bluffs orin the steeply cut roadbed betweenOceanside and Mission Bay may inhibit

rail traffic for 72 hours or. at worst. takeout the tracks. For planning purposes. the

line will be out of use for 7 days due todamage by landslides.

1be effects of the scenario earthquakeson tenninal facilities in downtown San

Diego will be serious. Those tenninalsserving marine facilities on the east side of

San Diego Bay are located in areas thatVJill experience severe ground shaking.

Marine Facilities (POfIS)

1be port area under the jurisdiction 01

the San Diego Unified Port Districtincludes portions 01 the cities 01 San

Diego. Chula Vista. Coronado. NationalOty. and Imperial Beach. Approximately2-1/3 miles of nonmilitary berths areavailable at the port facilities. lhey are

located at three principal sites: B Streetand Broadway piers. Tenth AvenueMarine Tenninal. and National CityMarine Tenninal. Virtually the entire port

of San Diego is built on artificial fiU.

Extensive liquefaction-induced lateral

spreading is possible all along the bayfront. This VJill affect structures builtbehind quay walls and also approaches(road and rail) to the dock area.

Figure 4. Water and waste water laclhlJes.

The line has been out of seMce from theborder toWn of Tecate eastward for manyyears lh!: to the loss of a major bri:Ige

stnx:ture. rot is stiD open from San Diego to

Tecale. a distance of about 25 miles.

Rail lines to San Diego cross areas 01

high 10 very high liquefaction susceptibil-

ity. Service along the ATSF line from Los

Angeles can be expected 10 be disrupted

south of Oceanside. Tracks are subject tolandslide damage or dislocation due toliquefaction where they cross me coastal

sloughs. and along Mission Bay. For

planning purposes. service will not berestored for 3 weeks after the earthquake.

1be BStreet Pier was constructed in

the early 1920s in several phases. 1beTransit Shed No.2 on the B Street Pierhas been renovated to serve as a cruiseship tenninal. Uquefactk>n will damagethe BStreet Pier. Pile-supported docksand piers. with the exception 01 the BStreet Pier. should fare well. but accessproblems may preclLKle their use dUringthe initial post-€<lrthquake period. For

CAlIFOflNIA GEOLOGY SEPTEMBER 1991



response planning purposes, it is

reasonable to assume that the port

facilities will not be fully usable (a fairly

conselVative assumption) for 3 days. The

loss of port facilities will have only

minimal impact on public welfare.

IMPACT ON UTILITY LIFELINES

Communications

This section deals with Emergency

Broadcasting System (ESS) stations and

inter-governmental communication

centers that are vital to emergency

selVices. Both the City and County of San

Diego operate communication facilities

for use as emergency operation centers.

The San Diego County Communications

Center is located at the Overland Avenue

County Operations Center in a part of

the city called Kearny Mesa. The facility is

housed in a mcxlified warehouse of tilt-upconcrete wall and steel frame. metal deck

roof construction. The center is operated

by the San Diego County Sheriffs

Department, The County Office of

Disaster Preparedness has its primary

communications center in this facility.

The City Operations Building in down

town San Diego contains the fire, police

dispatch. and emergency operations

center in the basement.

The county communications system

for departments other than the Sheriff

(roads. utilities. etc.l operates out of theCounty Operations Center in Kearny

Mesa. Although the facility is located in

an area of MMI VII. consoles rest on a

raised floor and on desks with no

anchorage against lateral forces. The

Office of Disaster Preparedness' commu

nication system operates as part of

"Station x." which includes the VHF twoway system to the EBS stations KKLQ

and KCBQ. This broadcast equipment for

the EBS is similarly desk-mounted with no

anchorage against lateral forces.

It may be assumed that the microwavesystem will be out of use due to the

effects of ground shaking on the align

ment of the antennae. For purposes of

the scenario. the microwave system will

be no more than 20 percent effective.

and it will not be fully effective for 3 days

following the earthquake.

The City of San DiegoAdministration

and Operations buildings are in down

town San Diego. They house fire and

police dispatch and the City emergency

operations center. These are located in

an area of high ground shaking (MMI

VllO. While damage to the buildings may

not be severe enough to cause collapse.severe nonstructural damage may be

sufficient to cause functional impainnent.

Electric Power

TheSan Diego Gas and Electric

Company (SDG&E.l distributes practically

all of the electrical power throughout San

Diego County. The actual selVice

territory. which includes southwestern

Orange County. covers 4.100 square

miles (double the size of the state of

Delaware). and it includes over 940.000

customers. Major transmission lines.

power stations, and principal substations

are shown in Figure 3. Two operating

power plants (Encina and South Bay) are

included in the planning area.

Transmission substations are essential

to the routing of locally generated power

and of power available from outside the

region affected by the earthquake. These

major substations. which contain banks of

switches, cireui! breakers. and massive

transformers. are particularly vulnerable

to damage by earthquake shaking. In

addition to the major transmission

substations through which high voltage

(greater than 230 kilovolts) is routed.

many small local substations provide the

vital links in the electrical power distribution network.

Transmission towers and lines are

principally subject to damage through

secondary effects. such as landslides and

other ground failures. Conductor lines

(usually distribution lines) swinging

together could cause many "bum downs."

The scenario earthquake will have a

definite impact on local power-generating

capabilities. In particular. damage or

disruption to the waler supply to the

power stations will have a critical effect

on the power generation capabilities. For

planning purposes. the South Bay Power

Plant should be considered inoperative for3 days and significantly reduced in

capacity for 1 112 weeks following the

scenario earthquake.

Water Supply

San Diego County is a semi-arid

region and depends almost entirely on

water imported from other areas. An

adequate supply of water is critical during

emergencies. not only for drinking

purposes and fire fighting. but also for

the operation of other utilities, such as

waste-water treatment.

The San Diego County Water

Authority. which encompasses a

1.412.5-square-mile area. serves a

population of approximately 2,106.000.

It receives its supply of water from the

Metropolitan Water District of Southern

California (MWDJ within San Diego

County. approximately 6 miles south of

the Riverside!San Diego county line. The

MWD is the sole source of the nonnal

and supplemental water for San Diego

County accounting for 90 percent of the

total water supply to the county (see

Rgure 4). The amount of water storage

in San Diego County varies significantly

among the different districts. The supply

will last from 3 days to several years.

For planning purposes. it is projected

that on e of the five San Diego CountyWater Authority aqueducts in the north

will fail with an estimated selVice outage

of 1 112 months. One member agency

with only a 3-day supply of water will

quickly become dependent on outside

sources of potable water.

Facility operations dependent on

water. such as the Point Loma Waste

water Treatment Plant (l-day supply of

tvater storage) and the SDG&.E South

Bay Power Plant (2- to 5-day supply ofwater storage capacity). will be function

ally impaired due to the lack of water.

For the scenario earthquake. the areas

of the water distribution system most

vulnerable to damage are those bordering

Mission Bay and San Diego Bay. coastal

areas. western Mission Valley. and the

Otay (ria Juana River) Valley. Mains

(both primary and secondary) passing

through these areas of recent alluvium

and artificial fill will suffer several breaks

per mile of pipe. Landslides in the Mt.

Soledad area. coastal regions of La Jolla.

the north wall of Mission Valley. and the

edges of Otay Mesa may also damage

facilities and distribution mains. As a

result, several of the above-mentioned

areas will be without water for up to 4

weeks following the scenario event. For

planning purposes, we also assume that

parts of La Jolla. Pacific Beach. Ocean

Beach. and Mission Beach will be without

water for up to 4 weeks following the

scenario earthquake.

CALIFORNIAGEOLOGY SEPTEMBER 1991 209



Figure 5. Natural gas tacilities and petroleum luels.

Natural Gas

The primary impact of the scenarioearthquake will be on the gas-distributionsystem where it crosses areas of highintensity and ground failure. [n Pacific

For planning purposes. the flow

capacity 01 the collection system carrying

waste water to the sewer system will bereduced by 50 percent, and 50 percent

of the service area will be nonfunctional.

The main sewer line along San DiegoBay will be out 01 service for 6 weeks.

Rupture of the tunnel below the streets of

downtown San Diego will take it out ofservice for 4 months, during which time

raw sewage will discharge into San Diego

Bay. Pumping Station No.2. the mostvital spot in the entire system. will be

functionally impaired lor 45 days.

Three transmission pipelines conveynatural gas to the San Diego area from

the north (Figure 5). Twe are located

inland. running along the mesas. Thesewill not be seriously affected by the

scenario earthquake. The third runs along

the coast and crosses several areas ofhigh to very high Iiquelaction susceptibil·

ity. This pipeline will be damaged by

lateral spreading at Soledad (Sorrento)Valley and by landslides along TorreyPines grade. and will be out 01 service for

more than 72 hours.

Mexican border and east as lar as Spring

Valley and Alpine. The principal compo

nents of the system are illustrated inRgure 4. The system collects. transports.

pumps. treats. and disposes of liquid waste

from the cities 01 Chula Vista. Coronado.

8 CajOn. Imperial Beach. La Mesa.

National City. and San Diego. and fromthe Lemon Grove. Montgomery. andOrlando. and from Spring Valley Sanitation

districts. The city also has an "emergency"

connection to Tijuana. The total now ofwaste liquid. all of which is treated at the

plant on Point Lorna. is currently about

180 million gallons per day.

As a result of the anticipated damageto the San Diego metropolitan sewer

system described abov€. the waste-water

connector line from Tijuana will be

interrupted for 60 days before nonnalservice is restored.

• EI Cajon

The metropolitan sewer system selVeS

virtually all 01 the populated metropolitanarea of San Diego and adjacent communities south 01 Del Mar. extending to the

Waste Water

.lemon Grove

.TIJUANA

.Chula Vista

----'.----.-------_.---_.---_ ..

• National City

TANK FARM

• Imperial Beach

NATURAL GAS FACIL IT IES

AND

, PETROLEUM FUELS,I MAJOR GAS TRANSMISSION

I PIPEliNE

I PETROLEUM PRODUCT

I PIPELINEI • PETROLEUM TERMINAL

.,_ ........o----'F"'A"'C,,'Le-1T'-'y - jI -.. . . . .•

.:

'\....••....~

\.

•, 5 MILES,

"""

o<>

'".,.Z

,\

,

.Oel Mar

.La Jolla

Because of failures in local water

distribution systems. segments of thepopulation will be asked to use emergency supplies. boil their water. or take

other measures against contamination lor1 to 4 days.

'"




Beach. POG'\t L..oma. and downtown.

repairs WID be completed WIthin 72 hours.but complete service restorat)oo \l,iB take

up to 2 v..'eeks. Coronado could be

without service for 2 to 4 months. until anew pipe Is installed across Ihe bay.

Pelro!eum Products

The """'*'"'" _ P;peIine. like

most of the utilities transmission facilinesfrom the north.• routoo pnmoriIy oJongthe mJond ' """" (Rgwe 51. and >hook! beoperational folbl.ing the event The tankfarm is located on liquefiable alluviumnear the nonh v.:alJ of Mission Valley.Because of lIs distance from the earthquake source, damage to the tank farmshould not be severe, Fires may result

where lines break al their junctionsWIththe tanks, The tanks themselves may be

damoged by .Jo.hmg !;quid<

The N a fuel pipeline to Point L..oma

will be damaged where It crosses the

Mission Bay. Lorna Portal area of high to

very high liquefaction susceplibihly. The

10th Avenue Marine Terminal fuel pier

wiD SUSlain heavy damage from lateral

spreading of the liquefJed fiJI along the

margins of San Diego Bay. Access to thefuel teonlna! and to the damaged

portiOnS of the Nav:i pipehne wiD be

difficUl and &mlted. dclaying repairs for

"""'"" days

REFERENCES

Lindvall. SC. Rockwell. T K" and Llndval,C.E., 1990, The seismic hazard of sanDiego revised: New evidence formagnitude 6+ Holocene earthquakes onthe Rose Canyon faull zone. In ProceedIngs of lhe 4th US Conlerence onEarthquake Engmeemg, v 1 Earth·quake El'IQlneenrlg Research InstJtute. 8

GemIO. Caldorl'll3. P 679-688

RetchIe. M.S.. Kahle, JE .. AIIunson, TG,Johnson, E.H., Olson. A.A.. Lagooo.H.J. StelnbllJgge, K.V., Cluff. LS ..

Haney. T,P" and Powers, J.E.. 1990.Planning scenario lor a major earthquake, san Dleoo-Tijuana metropolitanarea: California Department of Conserva·hon. DMsion 01 Mines and Geology

Special PubflCation 100, 181 p.Toppozada, T.R., and Parke. D.L. 1982.Areas damaged by GDlorna earthquakes. 1900-1949.Annual TechnicalReport 10 the U.S GeologICal Survey'Cali10rna 0Msl0n ol M,nes and GeologyOpen-File Report 82·17SAC, 65 P

Toppozada. T.R" Real. C.R., and Palke,D.L, 1981. Preparation of 150SelsmaJmaps and summaries 01 reported etlectslor pre-1900 California eaJ1hquakes,Annual Technical Repon to the U.S.GeologtcaJ Survey Caldornia DIVISIOfl 01Mines and Geology Open·File Report 8111SAC,182p

Marine Mining 2000 - April 5 • 10, 1992

The f.nglneenog FOl.IflWllon If \ c0opera-

tion IoWh the Uruversaty 01 Haw . . sManneMlOefab Teclvdogy Cen!er, and the ManneTochnology Sodely's CommJltee on M;?arineMlI'leral Resources. announce 1I confcrenceon Marine Mining 2000 to be held ;?at theKeauhou Beach HOle!. Kooa, H;?awaii Theconference ch<tlr IS "1lChael J CIUickWnk,and the CO'ChaIr IS Charles L Morgan. bothfrom thr UflM.>rslty 01 Hawaa

T h conference will exal'T'llnt and updato!tret'llb Ul exploratKWI and exploltahontechnology for marine mineral deposits

COIlCerrung their economic and ecological·

wstainable development. The follCNoing

nIne sessions will provide an overview ofthe current ;?activities and prospects In this

relatively ne\olo'disciphne

• 1'tv re. e l l l l upd;ne on kntMn<V1d cVItl(!pllted re5OUJ'Cti

• Mmeral exploration USing remote

• MLneral <iep0lt sampling• MIning system!> for the continental shelf

• Environmental hazards and Impactscoastal Sites

• Mining ¥lems for the deep wabedsdeep 0CNf I mu'Iing

• Eno.vorwnmktl hazards and mpacts• Madding technologiCal ~ , . . .• ~ t r a d a h o , l a I ccra-pls for manne

~ " AD conference manbers are encouraged 10

cOlltnbute papers IOf poster sessions orabstracts lor dJSCU5SlOrI al the time of

appilcatlOll. ProceedIngS for the conferencewiD be publl<Jwd In a special edItion of Marine

MinJng

EngIneering Fomdbbon conferences wereestablished in 1962 to pnMde a forum lorproblems and issues relevant to engineersfrom many disCIplines. The conferenceprovides momlng and evening sessions In\\.-tlich major presentations are made. It

ancIudes lime duTing lhe ahemoons for lid hocse!'Slons and informal dscussioos

For infonnanon. Cl:lI'Ud

0lar1es V. FreimaIf\. DirectorEllgq ......:1 iI og Foundalion345 47th StreetNew York. NY 10017212·705-7835'

CAUFORNtAOEOLOGY SCPTEMBER 1991'"



A Page for Teachers

EARTHQUAKE BIBLIOGRAPHY

The following bibliography was compiled by the National Center for Earthquake

Engineering Research. State University of New York at Buffalo.

Selected References fo r

Teachers

Alexander. T.. Plate TectonicsHas a Lot To Tell Us About thePresent and Future Earth

(5m;thson;an. 5(11). 38-47, 1975)

Alexander. T" Revolution CalledPlate Tectonics Has Given Us aWhole New Earth (Smithsonian,

5(10).30-40, 1975)American Red Cross Safety andSurvival in an Earthquake. LosAngeles Chapter (Los Angeles. CA :American Red Cross. 1982)

Anderson. D.L. The SanAndreas Fault (Scientific American. 225(5).52-68,1971)

Ballard, RD., Window on Earth's

Interior (National Geographic,150. 228-249, 1976)

Boll. B.A .. Earthquakes: A

Primer (W.H. Freeman, 1978)Bolt, B.A., Earthquakes (W.H.Freeman. 1988)

Boore, D.M., Seismology(Geohmes. 22(1). 40-41, 1977)

Brown. B.. & Brown W. HistoricalCatastrophes (Addison-Wesley,1974)

Canby. T.Y .. Can We PredictEarthquakes? (National Geo9,aphk. 149.830-835,1976)

Canby, T.Y .. & Baire, J.

California's San Andreas Fault(National Geographic. 143.38-52;1973)

FEMA Guidebook for Develop

ing a School Earthquake SafetyPmg<am (FEMA 88, 1985)

Gere, J.M .. & Shah, H.e. TerraNon Firma: Understanding andPreparing for Earthquakes.

(W.H. Freeman; 1984)

Golden. F.. The Trembling

Earth: Probing and Predicting

Quakes (Scribner's: 1983)

Hanif. M.. As the Earth

Quakes .. .What Happens?(Science and Children, 27(4). 3639, 1990)

Hanks. T.e., The NationalEarthquake Hazards Reduction

Program-Scientific Status (U.S.Government Printing Office. U.S.Geological Survey Bulletin 1659:1985)

Hodgson. J.H .. Earthquakes andEarth Structure (Prentice-Hall;1964)

lacopi. R.. Earthquake Country:How. Why and Where Earth·

quakes Strike in California(Lane, 1974)

Miller, M.M .. Our Restless Earth(National Geographic. 126, 140141; 1964)

Mogi. Earthquake Prediction(Academic Press: 1985)

Tufty. B. 1001 Questions Answered about Earthquakes.

Avalanches. Floods, and otherNatural Disasters (Dover Publications: 1969)

Walker. B.. & the editors of TimeLife Books. Planet Earth: Earthquake \fime-Life: 1981)

Yanev. P.. Peace of Mind inEarthquake Country, How toSave your Home and Life (SanFrancisco. CA: Chronicle: 1974)

Selected Books for Grades

K-3

Baker. K.. The Magic Fan(Harcourt. Brace. Jovanovich,1989)

Berger. M.. Jigsaw Continents(Coward, McCann, & Geoghegan.1977)

Challand. H.J.. Earthquakes

(Children's. 1982)

Curran. E., Mountains and

Volcanoes: What do You See?(Troll Associates, 1985)

Kaufman. J .. Joe Kaufman's

About the Big Sky, About theHigh Hills (Golden Press. 1978)

Lambert. D.. Earthquakes(Franklin Watts. 1982)

Larson. N.. Why do We Have

Earthquakes? (Creative Education.1982)

Mallhews. A., Earthquake(Ballantine. 1986)

May, J .. Why the Earth Quakes

(Holiday. 1969)

Merrians, D.. I Can Read About

Earthquakes and Volcanoes

[froll Associates, 1975)

Radlauer, RS .. Earthquakes(Children 's, 1987)

Simon. S .. Danger From Below:Earthquakes Past. Present, andFuture, (Four Winds. 1979)

Stein, Re.. The Story of the SanFrancisco Earthquake(Children's, 1983)

Winner. P.. Earthquakes (Silver.1986)

CAUfOflNIA GEOLOGY SEPTEMBER 1991



Selected Books for

Grades 4-6

Asimov. I.. How Did We FindO ut About Earthquakes?

(Walker. 1978)

Aylesworth. T.. Geologic Disasters: Earthquakes and Volca-noes (Franklin Watts. 1979)

Baker, K .. Th e Magic Fa n

(Harcourt. Brace, Jovanovich.1989)

Berger. M .. Jigsaw Continents

(Coward. McCann & Geoghegan.1977)

Cazeau. c.J .. Earthquakes(Follett. 1974)

Cole. J .. The Magic School BusInside the Ear th (Scholastic,1987)

Dudman. J .. Th e Sa n Francisco

Earthquake (Wayland. 1988)

Fodor. R.V .. What Does a Geolo·gist Do? (Dodd. Mead. 1977)

lacopi. R.. Earthquake Country(Lane, 1971)

Kiefer. I.. Global Jigsaw Puzzle,Story of Continental Drift

(Atheneum. 1978)

Larson. N .. Wh y Do We Have

Earthquakes? (Creative Education.1982)

Levine. E., I f Y ou L iv ed at th e

Time of the Great San Fran

cisco Earthquake (Scholastic.1987)

Markle. S .. Digging Deeper(Lothrop, Lee, and Shepard, 1987)

Merrians. D., I Can Read AboutEarthquakes and Volcanoes

[froll Associates, 1975)

Navarra, J.G.. Earthquake!(Doubleday, 19801

Nixon, H.. & Nixon. J.L, Earthquakes: Nature in Motion

(Dodd. Mead. 1981)

Paananen, E., Tremor Earthquake Technology in the SpaceAge (Julian Essner. 1982)

Rutland, J .. The Violent Earth(Random House, 1987)

Simon. S.. Danger From Below:Earthquakes Past. Present, andFuture (Four Winds, 1979)

Sullivan, Earthquake 2099(fiction) (Dutton. 1982)

Williamson, T., Understandingthe Earth (Silver Burdett. 1984)

Selected Books for Grades7-9

Asimov, L How Did We FindOut About Earthquakes?

(Walker, 1978)

Brandreth, G., Amazing FactsAbout Our Earth (Doubleday,1981)

Challand. H.J., Activities in theEarth Sciences (Children's. 1982)

Fodor, R.V .. Earth in Motion:The Concept of P la te Tectonics(William Morrow. 1978)

Fradin. 0.8., Disaster! Earthquakes (Children '5 . 1982)

Gilfond, H., Disastrous Earthquakes (Franklin Watts. 1981)

Jones, P.. The Forces of Nature(Children·s.1981)

Lauber, P., Earthquakes: NewScientific Ideas About How and

Why the Ear th Shakes (RandomHouse, 1972)

Raymo, C .. The Crust of OurEarth (Prentice Hall. 1983)

Rossbacher, LA., Recent Revolu-tions in Geology (Franklin Watts,1986)

Tributsch, H .. When th e SnakesAwake: Animals and Earth

quake Prediction (MIT. 1982) X

CALIFORNIA GEOLOGV SEPTEMBER 1991



• • • • • DMG Release • • • • •SPECIAL REPORT 162

MINERAL lAND CLASSlACATIONPortland cement concrete aggregale and

active mines of all other mineral commochues in the San Luis Obispo-SantaBarbara production-consumption regK:ln_

By Russel V, Miller. Judy WK!denheft

Cole. and John P Oinkenbean:l, 199137 . $2500

SpedaI Report 162 provides informatiOn on the estimated availability of. anddemand for. portland cement concrete(PCQ-grade aggregale resourcesWIthinthe San Luis ObIspo-Santa BarbaraPn:xIuction-ConsumptiOn (poQ Region.

The study area COVl."f$ 2.062 square miles

and includes major portions of l4'eStemSan Luis Obtspo and Santa Barbaracounties. Approximateiy 40 percent ofSan Luis Obispo County and 45 percentof Santa Barbara County have been

irrl.Jded within the P-C region and havebeen claSSIfied for PCC-grade aggregate.In this area. as in any urbaniZing area.importanl Iand-use decisions should bemade \l..ith fuU recognition of the region's

natural resources, This Is particularly

important \/Jith regard to resources ofhigh-grade construction aggregate used inportland cement concrete. PCC-gradeaggregate is an Indispensable buildingmaterial !hat is costly to lranspon. Thisclassification report documents lor theSan LuisObispo-Santa Barbara area:

I) the location of Pee·grade aggregate resources.

2) the quantIty of PCC-grade aggregate v.ithin those depostlS:

3) the Iocalion of aft actIVe mines

\l,.ithin the regiOn prodocing

commodities other than fill,

4) the demand lor aggregate v.,thmthe regK:ln for the next 50 years

This study "!as concb::lro as speofiedby the Surface MlOmg and Redamalion

At::t (SMARA) of 1975. s,\1ARA waspassed by the California Stale I..egtsIature

to: (I ) respond 10 the kY..s of sigrulicantmineral resources due 10 urban expansion; (2) obtain current informationconcerning the location and ~ u t y ofessential rnineraI deposits; and (3) ensureadequate mined-land reclamation. Toaddress mineral resource conservalion.SMARA mandated a two-phase processcalled dassincation-designatK>n. Theobjecliw: of lhe classifkation-designatlOnpnxess is to ensure. through appropriatelocal lead agency poOCies and procedures.that raw material is available whenneeded and does not become inaccessible

as a result of inadequate informationduring the land·use decision-makingprocess.

SMARA mandates that !Pdelines for

classifkation and designation be deYef..-

oped by the State MlI'ling and Geoklgy

Boam The BoanI originally adoptooformalSMARA guidelines 00 June 30.1978. SectjQO I. la of those guidelines

reqares the Stale Geologist to classifyspecified areas into Mineral ResourceZones (MHZ). Classifx:ation is the process

of identifying lands containing signifM:ar'lImineral deposits. based solely on geologicfaetOB \l,lthout regard 10 presenlland lb e

or CMor.ership. The Board recogruzes thaiconsIrucbon materials (sand. gravel. andcrushed stone) are produced regionally.

are used in every urban area of the Slate.and require spec:ial classilication data.

Section 1.3 of the guidelines reqwres thatclassification repoftS pertaining todeposIts of constTuCtion aggregalematerials ind.de the folou.ing informa·1m (I ) the location and estimated Iotal~ t l t y of construction aggregaleavailable for mining; (2) limits of themarket {consumptionJ region lhat these

potential resources wouJd supply; arxl(3) an estimate 01 the total quantity ofaggregate malerial that will be needed tosupply the consumption region lor thenext 50 years. This information will assrstthe Board in detennining the statewide or

regional significance of these typeS ofdeposits:'"

Coast Rock Products. Inc aggregate plant on the SIsquoc Rrver

Documents

California Geology Magazine September 1991