Slow Deformation and Transmission of Stress in the Earth

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GeophysicaMl onograph4 9
IUGG Volume 4
Slow Deformation and
Transmission of Stress in the Earth
Steven C. Cohen
Petr Vani(cid:127)ek
Editors
(cid:127) AmeriGcaeno phyUsnicioanl
(cid:127) InternatUionniooanflG eodaensdy
GeophysicMalo nograph/IUGGS eries
Library of CongressC ataloging-in-PublicationD ata
Slow deformationa nd transmissiono f stressi n the earth / edited by
Steven C. Cohen, Petr Vani(cid:127)ek.
p. cm. m (Geophysicalm) onograph4; 9/IUGG series4; )
Includesb ibliographies.
ISBN 0-87590-453-X
1. Rock deformation. 2. Plate tectonics. I. Cohen, S.C.
(Steven C.) II. Vani(cid:127)ek, Petr. 1935- .III. Series.
QE604. S57 1989
551.8mdc19 89-6456
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CONTENTS
Preface
Steven C. Cohen and Petr Vanf(cid:127)ek ix
Introduction
Steven C. Cohen and Petr Vani(cid:127)ek xi
1. Post-GlacialR eboundA nalysis for a Rotating Earth
DazhongH an andJ ohnW ahr 1
2. On the Figureso f the Earth
R. Tonn, ]. Zschau 7
3. ContemporaryV ertical CrustalM otion in the PacificN orthwest
SandforRd. HoldahlF, rancoiFsa uchera,n dH erbD ragert ] 7
4. Kinematics and Mechanics of Tectonic Block Rotations
AmosN ur, HagaiR on,a nd OonaS cotti 31
5. Plate Motions, Earth's Geoid Anomalies, and Mantle Convection
Fu Rong-shan4 7
6. Role of EpisodicC reep in Global Mantle Deformation
G. Ranalli and H. H. Schloessin 55
7. LayeredB lockM odel in Problemso f Slow Deformationso f the Lithospherea nd of
EarthquakeE ngineering
A.D. Gvishiani, V. A. Gurvich, and A. G. Tumarkin 65
8. Geodetic Measurement of Deformation East of the San Andreas Fault in Central California
JeanneS auberM, ichaelL isowskai nd SeanC . Solomon 71
9. Earthquakes'I mpact on Changesi n Height
i. lo6 87
10. Vertical Movement of Indo-Gangetic Plains
C. S. JoshiA, . N. Singh,M anoharL at 97
11. StrainA nalysiso f TectonicM ovementsF rom GeodeticD ata AcrossK rol and Nahan Thrusts
C. S. JoshiA, . N. Singha ndA tamP rakash 107
12. ViscoelasticD eformations and Temporal Variations in the Geopotential
RobertoS abadiniD, avidA . Yuena nd PaoloG asperini 115
13. Migration of Vertical Deformationsa nd Coupling of Island Arc Plate and SubductingP late
SatoshMi iura, HiroshiI shiia ndA kioT akagi 125
PREFACE
The papersp resentedin this monographa re basedo n presenta-
tionsm adea t the symposiumo n "Slow Deformationa nd Transmis-
siono f Stressin the Earth" at the XIXth GeneralA ssemblyM eeting of
the InternationaUl nion of Geodesya nd GeophysicsT. he symposium
was held on the campuso f the Universityo f BritishC olumbiai n
Vancouver,C anadao n August 15th and 17th 1987.
The editors would like to thank the authors, reviewers and AGU
staffw ho contributedt o the publicationo f this monograph.
Steven C. Cohen and Petr
Geophysical Monograph Series Slow Deformation and Transmission of Stress in the Earth Vol. 49
INTRODUCTION
A symposium entitled "Slow Deformation and movementsa nd modelso f the variousa spectso f the
Transmission of Stress in the Earth" was convened at earthquakec ycle.T he secondd ay covereda wider
the XIXth GeneralA ssemblyM eeting of the Interna- rangeo f issuess ucha s intracontinentald eformation,
tionalU nion of Geodesya nd GeophysicsT. hism ono- thermoviscoelasticitytr,a nsient creep, Pleistocene
graphi s basedo n presentationms adea t that sympo- deglaciationan d magmas olitonsS. ubsequentto the
siumw hichw ash eld on the campuso f the University symposiumt,h e presentersw ere invited to contribute
of BritishC olumbiain VancouverC, anadao n August papersb asedo n their presentationsfo r inclusioni n
15tha nd 17th, 1987.T he objectiveo f the symposium this volume. About half of the authors chose to
was to engage geophysicistsa nd geodesistsi n a submit papers, others declined, usually on the
discussiono f the mechanisms, models, and measure- groundst hat their papersw ere beingc onsideredfo r
ments of slow deformations and stress transmission publicatione lsewhere.T he submittedp apers were
in the Earth's crust and mantle. These deformations reviewedf or technicacl ontentf ollowingt he stan.dard
arec haracterizebdy their quasi-statinc aturei n which procedureos f the AmericanG eophysicaUl nion and
the effectso f accelerationar e negligiblec omparedt o returnedt o the authorsf or revisionsw hen required.
those due to gravitational, rheological, thermal, A few of the papers were rejectedo r withdrawn
chemical, and phase-changes tresses.P henomena during the review processT. he remainderf orm this
sucha s tectonicp late motions,p ostglaciarl ebound, volume.
mantle convection, strain accumulation, aseismic In this introduction we limit our overview to those
strain release, and polar motion-inducedd eforma- papersw hicha rep resentedin thisv olume.W e begin
tions are included in this description.F or many with a discussiono f the whole earth and perturba-
phenomenat he effectso f anelasticitya nd temporal tionst o its gravity field due to surfacel oads.
nonlinearitya re significant.T his view of slow defor- Sabadinie, t al. discussth e longw avelengthg ravity
mationsi s largelyg eophysicalF. rom a geodeticp oint signaturesd ue to present day and Pleistocenef orc-
of view, however, the maintenance of accurate coor- ings. It has been recognizedf or somet ime that the
dinateso f pointso n the Earth'ss urfacer equirest hat viscoelastirce sponseo f the Earth to surfacel oading
the geometryo f ongoingd eformationb e taken into and unloadingp roducest ime-dependenst ignatures
account[ InternationaAl ssociationo f Geodesy,1 987]. in the gravity field [e.g., Heiskanen and Vening
This necessitateasn understandingo f the geophysi- Meinesz, 1958].R ecently,t he analysiso f the orbit of
cal modelso f the temporal deformationsa nd their the Laser GeodynamicsS atellite( LAGEOS) has re-
predictivep owers. Thus the symposiump resenters suited in determinationo f the rate of change of
were challengedt o addresss uch key issuesa s: the geopotentiacl oefficientso f the Earth's gravity field
currents ta(cid:127)eo f understandingo f the phenomenao f sucha sJ 2o r C20T. hesec hangehsa veb eena ttributedto
slow deformation and transmission of stress, con- thev iscoclastriecb oundo f the Eartht o post-Pleistocene
trasts between alternative models, applicability of deglaciatioCn.h angeisn J2h aveb eenu sedb y a number
geophysicalm odels to prediction of positional of researchetros c onstraiens timateosf mantlev iscosity
changes,a nd assessmenot f model and parameter [e.g.,P eltier1, 985].I n thep resenpt apert hea uthorsu se
accuraciesT. hesew ere formidablec hallengesa nd as a linear,t ransienvt iscoclastrihc eologicaml odelo f the
suchw ere pursuedb y only someo f the authors. Eartht o showt hat the longw avelengtcho mponenotsf
The symposiumc onsistedo f approximatelyt hree the gravityf ielda re sensitivreo currentg laciaml elting
dozen invited and contributedp apers. About two- andc hangeisn theA ntarcticic es heemt assT. heir model
thirds of the papersw ere presentedo rally and the resultss uggestth at transiengt ravitationarel sponsedse -
remaindera s posterp apers.T he authorsc amef rom pends tronglyo n the ratiob etweens horta ndl ongt erm
over a dozen countriesi ncluding:C anada, China, viscosities.
CzechoslovakiaE, gypt, France, Great Britain, Hun- Continuingo n thet hemeo f postglaciarel boundH, an
gary, India, Italy, Japan,t he SovietU nion, Sweden, and Wahr discuss the effects of variations in the Earth's
and the United States.T he first day of the sympo- rotationo n the centrifugafl orce and henceo f the
sium focusedo n geodeticm easuremento f crustal deformatioonf theE arthi n responsteo thise ffectT. hey
xi
Copyright American Geophysical Union
Geophysical Monograph Series Slow Deformation and Transmission of Stress in the Earth Vol. 49
xii
find that the effecto f rotation on centrifugaflo rce Therei s,o f coursea, wider angeo f geophysicmalo dels
partiallyc anceltsh at of postglaciarel bounds hiftsin the whichc anb e discusseudn dert he generatlo pico f slow
Earth'si nertia tensor.T he analysisis then used to deformationFs.o r exampleG, vishianie, t al. discusas
estimate the effects of Earth rotation on the determina- layeredb lock model which can be appliedt o such
tionso f lowerm anfiev iscositayn dl ithospheritch ickness problemass t he coupledin teractioonf rigidl ithospheric
from postglaciarel boundm odelsf, ree air gravityd ata, blocksa nda deformablfea ultz one.T heys howh ow the
and relatives eal eveld ata.T hey find that the biggest principleosf convexa nalysicsa nb eu sedt o determinteh e
effectso ccuri n modelingth e relatives eal eveln eart he equilibriump ositionso f an interactingsy stemo f rigid
edgeo f the regiono riginallylo adedb y the sheet. and deformable blocks.
The rheologicaplr opertieosf the Earthd eterminteh e Nur, et al. focuso n a more specificp roblemb y
times caleo f perturbationisn responsteo applieds tress- reviewingth e theoryo f microblockro tationsp roduced
es.W hile mostc onvectiomn odelsa ssumae steady-state whens etso f paralleol r subparallecll,o sely-spacfeadu lts
creepl aw for manfier ocks[ e.g., Richter, 1973], the are subjectetdo sh6aringI.n itially,t he rotationo f the
possibilittyh at time and spatially-dependecnret epc an blocksis accompaniebdy motiono n the originalf aults.
influencpe ostglaciarel boundh asb eenr aisedb y several Howevera, ftera certaind egreeo f rotationh aso ccurred,
authors. Ranalii and Schloessin have considered several furtherm otioni sm orel ikelyt o resultin thef ormationo f
mechanismosf ' creep in the lower mantle including newf aultsr athert han slipo n the originalo nesa lone.
transienctr eep(cid:127)in whichs trainr atei s time-dependent, Thusv eryl argerr otationsa rea ccompaniebdy multiple
changesin creep due to pressurea nd temperature fault sets such as those observed in the western United
changeisn the locale nvironmendt,y namicre crysta!liza- States and elsewhere.
tion,a nds everaol thersp ossibilitieTsh. eys ummarizteh e The analysiosf geodeticd atat akesm anyf ormsI.n the
conditionsu nder which the varioust ime-dependent simplesfto rm, horizontaol r verticals urveyd atay ield
creepm echanismasre l ikelyt o bes ignificanfot r deforma- relative site locations. The variation in these relative
tion in the mantleA. lthoughth eyf indt hat someo f the positionws ith timec ano ftenb e correlatewd ith tectonic
creepm echanismthsa tt heyh avec onsidereadr eu nlikely phenomensau cha st he occurrencoef an earthquakteh, e
to be importantu nderc onditionsfo undi n the mantle, accumulatioonf strain,m ountainb uilding,e tc. On a
they concludeth at spatiala nd temporalv ariationsin somewhatm ore detailedl evel, numericalm odelso f both
manfiec reepc anb e significant. surfacea nds ubsurfacdee formationcsa nb e developed.
Tonn and Zschauh aver evisitedth e problemo f the Generallyth, esem odelsu sek nowledgoef localg eologi-
Earth'sf ossilb ulge,t he physicasl ignificancoef which cal featuresto derivea structurarle presentatioonf the
wasm uchd iscussead f ew decadesa go by Ledersteger regionu nders tudy.T hen the surfaced eformationasr e
[1967], Goldreicha ndT oomre[ 1969], ando thersT. hey constrainebdy the observationadla ta. Followingt his
studiedth e problemb y attemptingto tracet hee volution approachI,s hii et al. compareo bservationosf vertical
in time of the flatteningos f the geoid,t he hydrostatic motionin northeasteJrna panta keno vera severadle cade
figureo f the Earth andt he Earthi tself.T he hydrostatic times panw ith ther esultos f finitee lemenat nalyseTsh. ey
figuref latteningd ependso n relaxationin bulkw hichi s conclude that the Pacific Ocean side of the island is
asy et unknownI.t appearsh,o wevert,h att he unrelaxed subsidinagn dt he JapanesSee as idei s rising.
bulkm oduluysi eldsa valueo f flatteningw hichi si n good Relevelingasn ds eal evelr isea ss eenb y tideg augeasr e
agreemenwt ith otherp ublishedva luesI.t will be inter- the standardg eometricadla tau sedf or studyingc rustal
estingt o seet heir resultsfo r the Earth (topographic) uplifta nd/ors ubsidencBey. meanso f suchg eometrical
flatteningan dt hec onclusionthse yw ill drawf romt hese. data,H oldahl et al. found the uplift velocityf or the
The ideat hat the tectonicp latem otionsa rep arto f a coastaslt ripo f thes tateo f Washingtoann ds outhwestem
convectives ystemi n the mantle is one of the basic BritishC olumbiaC, anadara ngeb etween-2 mm and+ 3
geodynamitce nets[ Turcotte,1 975]. However,t he de- mm per year. In addition,t heir analysisin dicatesa
velopmenotf dynamicm odelsh asp rovento bea formi- coseismsicu bsidencoef 10 cm accompanyinthge 1946
dablep roblemin volvingth e nonlineacr ouplingo f me- VancouveIrs lande arthquakaen d a discernabilnec rease
chanicalg, ravitationalt,h ermal, and chemicale ffects. in upliftr atesin VancouveIrs lando vert he pastd ecade.
Consequentlnyu, mericaml odelersh aveu sedd eveloped The patterno f the uplifti s consistenwti th hypothesized
simplifiedm odelst o addressv ariousa spectso f the obliques ubductionn, ormals ubductiona, nd non-sub-
problemI.n ordert o studyt he relationshibpe tweenth e ductivec onvergencoeff the south,c entrala, ndn orthern
platem otionsm, antlef low, and geoidu ndulationsF,u partso f the ishnd,r espectivelTyh. e resultss eemt o be
employsth e Boussinesaqp proximatiotno the Navier- congruenwt ith the postulatesdu bductiozno neu nderly-
Stokese quationin whichd ensityp erturbationasr ec on- ing the wholer egion.
sidereidn thec onservatioonf m omentumeq uationosn ly Localized co, seismic vertical movement of several cen-
to the extentt o whicht heya ffectth e gravitationablo dy timetersa ssociatewdi th the 1985 LakeB alatonH, unga-
force term. The model is used to determine the correla- ry earthquakoef magnitude5 .6 is reportedb y Jo6.H is
tion coefficienbte tweenth e poloidacl omponenotsf the studyi s basedo n first order levelingsb racketingth e
velocityo f platem otionsa ndt he surfacvee locityfi eldo f seismiecv ent;t hem ovemenits clearlyd etectablaeg ainst
convection. the overalbl ackgrounsdu bsidencoef 0.2 mm per year
Copyright American Geophysical Union
Geophysical Monograph Series Slow Deformation and Transmission of Stress in the Earth Vol. 49
xiii
pervadintgh ea reao f interestP. articulaart tentionis p aid increasecdo mputation.apl owerW. ith increasinfgr e-
to thed eterminatioonf thes tatisticasli gnificancleev eol f quencyt,h em odelsre quiredto explainb otht heg eodetic
the detectedm ovemenat ndi ts horizontagl radient. and nongeodetimc easurementast, their observational
Selectefdir sto rderr epeatedle velingws erea lsou sed accuraciewsi,l l havet o considetrh ec ouplingo f mechani-
by Joshi,e t al. to computet he linearv erticalc rustal cal and thermalp rocesseasn d take into accountt he
motionp atterni n the Indo-Gangetipc lains.F rom the structuraaln dg eometricco mplexitoyf individuatle cton-
analysitsh ey deducedth at severael arthquakesw,h ich ic environments.
haveo ccurredd uringt he pastf ive decadeisn the area,
hadc oseismuicp liftsr angingf rom a few centimetertso
over 20 cm. The overallp atternss how tmiformt ilts References
apparentlays sociatewdi th tectonicp rocesseTsh. eset ilts
seemt o suggestth at the downwarpingo f the northern Goldreich, P., and A. Toomre, "Some Remarks on
edgeo f the Indianp latei s continuing. PolarW andering,"J . GeophysR.e s.,7 4, 2555-2567.
In a separatset udy,J oshie, t al. analyzeda four times 1969.
observeds,m all,1 50 m by 150 m, triangulationne twork Heiskanen,W .A. and F.A. Vening Meinesz, "The
coveringa tectonicalliyn terestinpga tchd ividedb y two Earth and its Gravity Field," Mc-Graw-Hill, 1958.
closelys pacedp aralletlr ustf aultsi n the Kalawara reao f InternationaAl ssociationo f Geodesy,S pecialS tudy
HimachaPl radeshst ateI,n dia.T heyh avee stimaterdi gid Group 4.96, Four-DimensionalG eodeticP osition-
blockt ranslationasn d homogeneousst rainw ithin the ing" P. Vanff:ek, editor, ManuscriptaG eodaetica,
blocksS. izeablec hangeisn the dilatationo f the blocks-- 12(3), 147-222, 1987.
the only reliablyd eterminablpea rameter--occurrebde - LederstegeKr.,, "TheE quilibriumFi gureo f theE arth
tween 1973 and 1986. The estimated direction of maxi- andt he NormalS pheriod,"in AnalysePdr oceedinogf
mums heairs c ompatiblwe ith theg eometroy f thef aults. theI nternationaSly mposiuomn theF igureo f theE arth
Saubere, t al. uset riangulatioann dt rilaterafiodna tat o and RefractionK, . Ledersteger,e ditor, pp. 20-22,
estimateth e shears trainr atesi n the Diablo Rangeo f Austrian Geodetic Commission, Vienna, Austria,
CentralC aliforniaa nd to estimates lip ratesa longt he March, 1967.
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ing stationslo catedc loset o the Paicinesfa ult indicate Mantle Viscosity:R esults From a New Normal
shorteninagt a rate5 .7 -+ 2.7 mm/yro vera 30 km wide Mode Method for the Inversion of Viscoelastic
zone.T he orientationo f this shorteningis consistent RelaxationS pectra,"J . GeophysR.e s.9 0, 9411-9421,
with the orientationo f the major fold structuresin the 1985.
region.F urthers outha nd east,n earC oalingat,h e esti- Richter, F.M., "Dynamical Models for Sea Floor
matedr ateo f right-laterasll ipo n the Calaveras-Paicines Spreading,"R ev. GeophysS. paceP hysics1, 1, 223-
faults ystemis 10 mm/yr. 287, 1973.
The papersp resenteidn thisv olumet, heo therp apers Turcotte, D.L., "The Driving Mechanism of Plate
presenteda t the IUGG symposiuma, nd the general Tectonics,"R ev.G eophysS.p acPe hysics1,3 , 589-590,
scientifilcit eraturein dicateth atg eodetidc ataa rep rovid- 1975.
ing manyi mportanct onstraintosn geophysicmalo dels.
Time-dependepnot sitiond ataa rep articularliym portant
for studyingth ee arthquakcey clea, ndb othp ositiona nd Steven C. Cohen
gravitationdala tah avec ontributetdo studieso f postgla- GeodynamicsB ranch
cialr eboundI.n sighti ntom antlec onvectioann dt ectonic Laboratoryfo r TerrestrialP hysics
processehsa s been advancedu sing varioust ypeso f GoddardS paceF light Center
geodetico bservationLse. ssp rogreshs asb eenm adei n Greenbelt, MD 20771
applyingge ophysicmalo delsto thes ystematpicr ediction
of geodeticp ositionc hangeso r correctionto geodetic Petr Vanff:ek
observationIsn. the future, geophysicaml odelsw ill Departmento f SurveyingE ngineering
evolveb asedo n a mixture of geodetic,g eophysical Universityo f New Brunswick
(seismicm, agnetich, eatf low) andg eologicadla ta.M od- Fredericton, New Brunswick
eld evelopmenatns dd ataa nlayswisi ll beg reatlya idedb y Canada
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