Geodynamics Geodymanics Series 1. Dynamicso f Plate Interiors 17. ProterozoicL ithosphericE volution A. W. Bally, P L. Bender,T . R. McGetchin,a nd R. I. Walcott A KrOner (Editor) (Editors) 18. Circum-PacificO rogenicB elts and Evolutiono f the Pacific Paleoreconstruction of the Continents Ocean Basin M. W. McElhinny and D. A. Valencio( Editors) J. W. H. Monger and J. Francheteau( Editors) Zagros,H indu Kush, Himalaya: GeodynamicE volution 19. TerraneA ccretiona nd OrogenicB elts H. K. Gupta and F. M. Delany (Editors) Evan C. Leitch and Erwin Scheibner( Editors) Anelasticityi n the Earth 20. Recent Plate Movements and Deformation ED. StaceyM, . S. Paterson,a nd A. Nicholas( Editors) K. Kasahara (Editor) Evolution of the Earth 21. Geologyo f the USSR: A Plate-TectonicS ynthesis R. J. O'Connell and W. S. Fyfe (Editors) L. P Zonenshain,M . I. Kuzmin, and L. M. Natapov; B. M. Page (Editor) Dynamicso f PassiveM argins R. A. Scrutton (Editor) 22. ContinentalL ithosphere:D eep SeismicR eflections R. Meissner, L. Brown, H.. Diirbaum, W. Franke, K. Fuchs, Alpine-MediterraneanG eodynamics and E Seifert (Editors) H. Berckhemera nd K. Hsii (Editors) 23. Contributionso f SpaceG eodesyt o GeodynamicsC: rustal 8. Continental and Oceanic Rifts Dynamics G Pallmason, P Mohr, K. Burke, R. W. Girdler, R. J. D. E. Smith and D. L. Turcotte (Editors) Bridwell, and G E. Sigvaldason( Editors) 24. Contributionso f SpaceG eodesyt o GeodynamicsE: arth Geodynamicso f the EasternP acific Region,C aribbean,a nd Dynamics Scotia Arcs D. E. Smith and D. L. Turcotte (Editors) Ramon S. J. Cabrd (Editor) 25. Contributionso f SpaceG eodesyt o Geodynamic:T echnology 10. Profileso f OrogenicB elts D. E. Smith and D. L. Turcotte( Editors) N. Rast and E M. Delany (Editors) 26. Structure and Evolution of the Australian Continent 11. Geodynamicso f the WesternP acific-IndonesianR egion Jean Braun, Jim Dooley, Bruce Goleby,R ob van der Hilst, ThomasW . C. Hilde and Seiya Uyeda (Editors) and Chris Klootwijk (Editors) 12. Plate ReconstructionF rom PaleozoicP aleomagnetism 27. Mantle Dynamicsa nd PlateI nteractionsin EastA sia R. Van der Voo, C. R. Scotese,a nd N. Bonhommet( Editors) M. E J. Flower, S. L. Chung, C. H. Lo, and T.E Lee 13. ReflectionS eismologyA: Global Perspective (Ediwrs) Muawia Barazangi and Larry Brown (Editors) 28. The Core-Mantle BoundaryR egion 14. ReflectionS eismologyT: he ContinentaCl rust Michael Gumis, Michael E. WysessionE, lise Knittle, and Muawia Barazangi and Larry Brown (Editors) BruceA . Buffett (Editors) 15. Mesozoic and Cenozoic Oceans 29. Ice Sheets,S ea Level, and the Dynamic Earth KennethJ . Hsii (Editor) Jerry X. Mitrovica and Bert L. A. Vermeersen(E ditors) 16. CompositionS, tructure,a nd Dynamicso f the Lithosphere- 30 Plate BoundaryZ ones AsthenosphereS ystem SethS teina nd JeffreyT . Freymueller K. Fuchs and C. Froidevaux (Editors) Plate Boundary Zones Seth Stein Jeffrey T. Freymueller Editors Geodynamics Series Volume 30 American Geophysical Union Washington, Publishedu ndert he aegiso f the AGU Books Board JohnE . Costa,C hair; Gray E. Bebout,D avid Bercovici,C arl T. FriedrichsJ, amesL . Horwitz, Lisa A. Levin,W . BerryL yonsK, ennethR . MinschwaneDr,a rrellS trobela, ndW illiamR . Young, members. Library of CongressC ataloging-in-PublicationD ata Plateb oundaryz ones/ SethS tein,J effreyT . Freymuellere, ditors. p. c.m.-- (Geodynamicss eries; v. 30) Includesb ibliographicarl eferences. ISBN 0-87590-532-3 1. Platet ectonicsI.. Stein,S eth.I I. FreymuellerJ, effreyT . III. Series. QE5 ! 1.4.P564 2002 551.1' 36--dc21 2002026230 ISBN 0-87590-532-3 ISSN 0277-6669 Copyright2 002 by the AmericanG eophysicaUl nion 2000 Florida Avenue, N.W. WashingtonD, C 20009 Figurest,a blesa, nds horte xcerptsm ayb e reprintedin scientificb ooksa ndj ournalsif the sourceis properlyc ited. Authorizatiotno photocopiyte msf or internaol r personauls e,o r thei nternaol r personauls eo f spe- cific clientsi,s grantedb y theA mericanG eophysicaUln ionf or librariesa ndo theru sersre gistered witht heC opyrighCt learancCe enter( CCC)T ransactionRale portingS ervicep, rovidedth att heb ase feeo f $1.50p erc opyp lus$ 0.35p erp agei s paidd irectlyto CCC,2 22 RosewooDd r., DanversM, A 01923. 0277-6669/02/$01.50+0.35. Thisc onsendt oesn ote xtendto otherk indso f copyings, ucha sc opyingfo r creatingn ewc ollective workso r for resale.T he reproductiono f multiplec opiesa nd the use of full articleso r the useo f extracts,i ncludingf iguresa nd tables,f or commerciapl urposesre quiresp ermissionfr om the AmericanG eophysicaUl nion. Printed in the United States of CONTENTS Preface Seth Stein and Jeffrey T. Freymueller vii Introduction Plate Boundary Zones: Concept and Approaches Seth Stein and Giovanni F. Sella Kinematics of Plate Boundary Zones Space Geodetic Measurementso f Plate Boundary Deformation in the Western U.S. Cordillera Richard A. Bennett, James L. Davis, James E. Normandeau, and Brian P. Wernicke 27 GeophysicalI nterpretation of GeodeticD eformations in the Central Mediterranean Area R. Devoti, C. Ferraro, R. Lanotte, V. Luceri, A. Nardi, R. Pacione, P. Rutigliano, C. Sciarretta, E. Gueguen,G Bianco, and F. Vespe 57 Tectonic Processesin the Eurasian-African Plate Boundary Zone Revealed by Space Geodesy Gyula Grenerczy 67 Evidencef or Block Rotationsa nd Basal Shear in the World's FastestS lipping Continental Shear Zone in NW New Guinea Colleen W. StevensR, obertM cCaffrey, YehudaB ock,J oachimF . Genrich, Manuel Pubellier, and CecepS ubarya 87 Crustal Block Rotations and Plate Coupling Robert McCaffrey 101 Comparison of GPS, Seismologicala, nd GeologicalO bservationso f Andean Mountain Building Eryn R. Klosko,S ethS tein,D avid Hindle, JonasK ley, EdmundoN orabuena, TimothyD ixon, and Mian Liu 123 DisplacementsS, trains and Rotationsi n the Central Andean Plate Boundary Zone D. Hindle and J. Kley 135 The Dead Sea Basin, Its Structural Setting and Evaporite Tectonics Abdallah S. A1-Zoubi 145 Earthquakes in Plate Boundary Zones The Global Moment Rate Distribution Within Plate Boundary Zones Cornd Kreemer, William E. Holt, and A. John Haines 173 Correlationo f [(cid:127)-ValueW ith SpreadingR ate for Strike-SlipE arthquakeso f the Mid-Oceanic Ridge System Amy R. Langenhorsta nd Emile A. Okal Plate Tectonicsa nd Earthquake Potential of Spreading Ridges and Oceanic Transform Faults Peter Bird, Yah Y. Kagan, and David D. Jackson 203 Complexities of Transform Fault Plate Boundaries in the Oceans JeffreyJ . McGuire, ThomasH . Jordan, and Jian Lin 219 The January 26, 2001, Bhuj Earthquake and the Diffuse Western Boundary of the Indian Plate Seth Stein, Giovanni Sella, and Emile A. Okal 243 The 01/26/2001, Bhuj, India, Earthquake: Intraplate or Interplate? QingsongL i, Mian Liu, and YouqingY ang 255 Dynamics of Plate Boundary Zones On the Evolution of Motion Across Diffuse Plate Boundaries StephenZ atman and Mark A. Richards 265 A Review of Using thef c'J(cid:127) Diagram to Evaluate Continental Deformation David Coblentz and Kurt Stiiwe 283 A Dangling Slab, Amplified Arc Volcanism,M antle Flow and SeismicA nisotropy in the Kamchatka Plate Corner JeffreyP ark, VadimL evin, Mark Brandon, JonathanL ees, Valerie Peyton, Evgenii Gordeev, and Alexei Ozerov 295 Crustal Shortening and Extension in the Central Andes: Insights From a ViscoelasticM odel Mian Liu, YouqingY ang,S eth Stein, and Eryn Klosko 325 Variations in Inelastic Failure of Subducting Continental Lithosphere and TectonicD evelopment: Australia-Banda Arc Convergence Kush Tandon,J uan M. Lorenzo,S ri Widiyantoro,a nd GeoffreyW . O'Brien 341 The Closed Upper-Mantle Circulation of Plate Tectonics Warren B. Hamilton 359 Plate Tectonicsa s a Far-From-Equilibrium Self-Organized System Don L. Anderson PREFACE An importancth angein ideasa boupt latet ectonichsa sb eent her ecognitiotnh att heb oundaries betweenp latesa reo ftenb roadz oneso f deformationra, thert hant hen arrowb oundarieosr iginally assumeidn platet ectonicth eoryH. ence,a lthoughit usedt o be commonto straddlteh eS anA ndreas fault andv iew onel eg asb eingo n theP acificp latea ndt he otheri n NorthA merica,i t is now rec- ognizedt hat sucha straddlew ouldr equirea 1500-kml eg spana crossth e plateb oundaryz one extendinga crossm ucho f westernN orthA merica. Althoughs uchz onesw erer ecognizefdr omt he wide distributioonf seismicitya,c tivef aulting, and extremet opographayl ongp lateb oundariesth, e advento f spaceg eodesyh asd ramatically increasedin teresitn studyingth em.P lateb oundarieasr oundt he world increasinglsyp routG PS antennasw, hicha re yieldingd etailedv elocityf ieldss howingp reviouslyu nimaginablvei ewso f how motionb etweenp latei nteriorsis distributeidn spacea ndt ime.T he velocityf ieldsa reb eing integratewd ith seismologicagle, ologicatlo, pographiacn, do therd atat o constraiann dt estm odels of the dynamicos f plateb oundariesS.u chi ntegratedap proacheasr e alreadyp rovidingim portant new insightsin to manya spectso f plateb oundaryp rocesses. The goalo f thisv olumei s to illustrates omeo f the approacheasn dr esultsc omingf rom these studiesG. ivent he rangeo f suchs tudiesw, hichp resentlys pana lmoste veryp lateb oundaryz one, the volumei s intendeda s a samplerra thert hana comprehensivseu mmaryW. e haveo rganizedit aboutt hreem ajort hemes.T he firsta res tudieso f them otionsw ithinp lateb oundaryzo ness, how- ingh owd ifferentte chniqueasr eb eingi ntegratetdo identifya ndd escribteh em otionsT. he second focuseos ne arthquakeins p lateb oundarzyo nesa ndt her elationo f theo veralbl oundarzyo ned efor- mationt o oneo f its mosts pectaculaarn dh azardoums anifestationTsh. e thirda ddresseths ei ssues of how the kinematicr esultsa nd other data can be used to investigatet he mechanicso f plate boundaryz onesa ndt heirr elationt o large-scalpe latet ectonicp rocesses. We thankt he authorsf or their effortsi n preparingp aperss uitablef or a generala udiencea nd acceptintgh ed elaysth atr esultf romb ookp ublicationW. e alsot hankr eviewersfo r theirt hought- ful commentsW. e havee njoyedp uttingt ogethetrh isv olumea ndh opei t providesre adersw ith a flavor of this rapidly-evolvingfi eld. Seth Stein Northwestern University JeffreyT . Freymueller Universityo f Alaska Plate BoundaryZ ones' Concepta nd Approaches Seth Stein and Giovanni F. Sella Departmento f GeologicalS ciencesN, orthwesternU niversityE, vanstonI L 60208 An importanet volutionin ideasa boutp latet ectonicsis ther ecognitionth atb oundaries betweenp lates are often broad zones,r ather than the idealized narrow boundaries assumedin the rigid platem odel.I nitial evidencefo r this conceptc amef rom the distri- butiono f seismicitya, ctivef aulting,a ndt opographyth at showeda broadz oneo f defor- mationa longa numbero f plateb oundariesIn. recenty earss paceg eodetics tudiesh ave confirmedth e ideao f broadb oundaryz onesb y showingt hato n manyb oundarieas sig- nificantf ractiono f the plate motiono ccursa t considerabldei stancesfr om the nominal boundaryIn. thesec asesi,n steado f viewingt hez onea sa narrowb oundaryb orderedb y "intraplate"e arthquakeasn dd eformationi,t is regardeda s a broadb oundaryz onew ith- in whicht he earthquakeasn dd eformationre flectt he distributiono f motionb etweent he interiorso f two majorp lates.I n thisv iew, a boundaryz oneo ccursw herem otioni s dis- tributedo vera zones ignificantlyb roadert hant her egiono f elasticd eformationa ssociat- ed with the earthquakcey clea longt he nominalp lateb oundaryC. onverselyw, e view the platei nteriora s the regionw ithin which site velocitiesa re well describedb y rotations abouta singleE uler pole. Spaceg eodesyc, ombinedw ith seismologyt,o pographya, nd structurasl tudiesi,s givingi ncreasinglby etterv iewso f how motionw ithinp lateb ound- ary zonesv ariesi n spacea ndt ime. In differenta reas,s tudieso f plateb oundariefsi nd a rangeo f kinematicb ehaviorfr om diffused eformationzo nest o discretem icroplatesT.h e kinematicd atai n turnp rovidev aluablein formationa boutp lateb oundarym echanicsF. or example,t hey give insighti nto the complexi ssueso f how motiona t convergenpt late boundaryz onesi s dividedi nto seismica nd aseismicm otiona t the trench,t he primary platei nterfacea, ndd eformationo f the overridingp late.T hey similarlyg ive insighti nto the mechanicso f uplift andm ountainb uilding.T heses tudiesh avei mplicationsfo r soci- ety becausea bout4 0% of Earth'sp opulationli vesw ithinp lateb oundaryz ones,a nd are thusv ulnerablet o geologich azardsn otj ust at the nominalb oundaryb, ut alsoo ver the broadb oundaryz one. INTRODUCTION herently,s ucht hat mostd eformation,s eismicityv, olcanism, and extreme topographyo ccur at their boundariesI.n his The central concepto f the theory of plate tectonics,t he classicp aper introducingt ransformf aults, Wilson [1965] primary intellectualu nderpinningo f the moderne arth sci- suggestedth at "platesb etweenm obile belts are not readily ences,i s that large regionso f the earth'ss urfacem ove co- deformede xcept at their edges."A lthought his model of rigid plates with narrow boundariesp rovidedm uch of the power of plate kinematics,a llowingt he derivationo f mod- Plate BoundaryZ ones GeodynamicsS eries3 0 els by Euler vector summationf or plate circuits,i t was rec- Copyright2 002 by the AmericanG eophysicaUl nion ognizedt o oversimplifyc ontinentalc omplexities.M organ 10.1029/030GD01 [1968] notedt hat "Such featuresa s the African rift system, 2 PLATE BOUNDARY ZONES: CONCEPTS AND APPROACHES Cameroont rend, and Nevada-Utahe arthquakeb elt are most Mao, 1997; Larson et al., 1997; Sella et al., 2002]. This likely the type of distortiond eniedi n the rigidity hypothe- agreementi s consistentw ith the predictiont hat episodic sis. Nonethelessi,t is of interestt o seeh ow far this simpli- motion at plate boundariesa, s reflectedi n occasionalla rge fying concepto f rigidity can be applied." earthquakesg, ives rise to steadym otion in plate interiors Using the rigid plate assumptionm, odelsf or global rela- due to damping by the underlyingv iscousa sthenosphere tive plate motion were derived by combiningd ata along [Elsasser, 1969]. plate boundariesR. ateso f plate motioni nferredf rom mag- Despitet he power of the rigid plate model, it was recog- netic anomaliesa t midoceanr idges,t ogetherw ith directions nized that boundariesb etweenp latesa re oftenb road,r ather of motion inferred from the azimuths of transform faults and than the idealized narrow boundariesa ssumedi n the rigid earthquakes lip vectorsa t plateb oundariesw, ere invertedt o plate model. The initial evidencef or this conceptc omes yield modelso f geologicallyi nstantaneou(sa veragedo ver from the distribution of seismicity and the topography, the pastf ew million years)m otionb etweenp lates[ Morgan, which often imply a broad zone of deformationb etween 1968; Le Pichon, 1968; Chase, 1972, 1978; Minster et al., platei nteriors.T his effect is especiallye videntw ithin conti- 1974; Minster and Jordan, 1978; DeMets et al., 1990, nents, such as the India-Eurasia collision zone in the 1994]. Suchm odelsc onsisto f a set of angularv elocity vec- Himalayas,t he Pacific-NorthA mericab oundaryz onei n the tors (Euler vectors)s pecifyingt he motiono f eachp late rel- WesternU .S., or the Nubia-Soma!iab oundarya t the East ative to one arbitrarily fixed plate. This approacha ssumes African rift. Broad boundaries also occur at active ocean- that plate interiorsd eforma t a low (ideally zero) rate com- continentm argins[ Stevense t al., this volume; Tandone t al., paredt o motionb etweent hem, which occurso nly at narrow this volume] and in oceanicl ithosphere,a s in the central boundaries. Hence Euler vectors derived from data from dif- Indian Ocean or along somem ajor transforms[ McGuire et ferent boundariesc an be combinedb y vector addition. al., this volume]. Plate boundary zones, as indicated by Successivem odelsh ave been developedu sing more and earthquakesv, olcanism,a nd other deformation,a ppeart o betterd ata, and verified usingi ndependendt atap rovidedb y cover about 15% of the Earth's surface( Figure 1) [Gordon space-basedg eodetics ystems[ Smith and Turcotte,1 993]. and Stein, 1992; Stein, 1993; Gordon, 1998; 2001]. These include Very Long Baseline radio Interferometry Plate boundaryz ones, althoughr ecognizedp rior to the (VLBI) [Clark et al., 1987], SatelliteL aser Ranging (SLR) advent of spaceg eodesy,w ere difficult to study because [Smith et al., 1990], the Global PositioningS ystem (GPS) plate motion models were derived using only data from [Dixon, 1991; Segall and Davis, 1997], and the Doppler plateb oundariesa ndt husp redicto nly the integratedm otion Orbitography and Radiopositioning Integrated Satellite acrosst hem. In recenty ears,h owever,s paceg eodetics tud- System( DORIS) [Cazenavee t al., 1992]. Theset echniques ies like those discussed in this volume have confirmed the combinep recise satellite-basedti ming, ranging, and orbit idea of boundaryz ones, are resolving the motion within estimationt o measuret he positionso f geodeticm onuments them, and are providingk ey data for investigationso f their to centimetera nd better accuracy,s uch that measurements mechanicsA. commont hemee mergingi s that often (but not over time yield preciser elative velocities. always) a nominalp late boundary,s ucha s the SanA ndreas By usings itesi n the interior of differentp lates,s paceg e- fault, accommodatetsh e largests inglep ortiono f the relative odesya voidst he assumptiono f plate rigidity and in fact per- plate motion, and is the locus of the largeste arthquakes. mits the rigidity to be quantified.T he different space-based However, a significantf raction of the motion and hence systemsy ield comparablev elocity data, which can be com- seismicityo ccursa way from the nominalb oundary( Figure bined. Becauseo f the relatively lower cost and portability, 2). Thus instead of viewing the region as a single plate most of the data presentlyu sed are from GPS. (Another boundaryf ault surroundedb y "intraplate"e arthquakesa nd spaceg eodetict echnique,S yntheticA perture Radar inter- deformation,i t is regardeda s a plate boundaryz one within ferometry( InSAR) from satellites[ Biirgmanne t al., 2000], which earthquakesa nd deformationr eflect the distribution shows relative motion within an image tens to a hundred of motionb etweent he interiorso f two major plates.W e thus kilometersa crossb, ut not absolutep ositionso n a plate-wide regarda plate boundarya s a broadz one when its width sig- or global scale.I nSAR is thus used for earthquakeo r fault nificantly exceedst hat of the region of elasticd eformation studiesb, ut not for larger-scalea pplications.) associatewd ith the earthquakec yclea longt he nominalp late Velocitiese stimatedfr om spaceg eodesyw, hich spano nly boundary. a few years,a re generallys imilart o thosep redictedb y glob- Spaceg eodesye, speciallyw hen combinedw ith seismol- al plate motion models that span several million years ogical, topographic,a nd structurals tudies,i s giving in- [Robbinse t al., 1993; Argus and Heftin, 1995; Dixon and creasinglyb etterv iews of how motion within plate bound- STEIN AND SELLA 3 EU NA AF PA AN Figure 1. Plateb oundaryz onesa ndr elativep latem otionsf or the NUVEL-1 globalp latem otionm odel.A rrow lengths arep roportionatlo thed isplacemenift platesm aintaint heirp resenrte lativev elocityf or 25 Myr. Divergencea crossm id- oceanr idgesi s shownb y diverginga rrows.C onvergencies shownb y singlea rrowso n the underthruspt late. Plate boundariesa re showna s broadz onesi mplied by seismicityt,o pographyo, r other evidenceo f faulting.F ine stipple showsm ainlys ubaeriarle gionsw heret hed eformationh asb eeni nferredf rom seismicityt,o pographyo,t here videnceo f faulting,o r somec ombinationo f these.M ediums tipples howsm ainlys ubmarinree gionsw heret he nonclosuroef plate circuitsi ndicatesm easurabled eformation;in most casest hesez onesa re also markedb y earthquakesC. oarses tipple showsm ainly submarinere gionsw heret he deformationis inferredm ostlyf rom seismicityT. he geometryo f these zones,a nd in somec asest heir existencei,s underi nvestigation[ Gordona nd Stein, 1992]. ary zonesv ariesi n spacea nd time. Possibles patialv aria- Our purposeh erei s to providea n overviewo f someo f the tions include a single fault systemt aking up most of the approachesis, suesa, ndr esultse mergingfr om plateb oundary motion[ e.g.P rescotte t al., 1981], a smoothd istributiono f zone studiesT. his paperi s not intendeda s a comprehensive motion [e.g. England and Jackson,1 989], or motiont aken review simplyb ecauseo f the volumeo f suchs tudies. up by a few relativelyl argem icroplateso r blocks[ e.g.B eck, 1980; Engeln and Stein, 1984; Acton et al., 1991; Thatcher, TECHNIQUES FOR STUDYING PLATE BOUNDARY 1995; Stein et al., this volume]. Each of thesep ossibilities ZONES occurs,s ometimesw ithin the sameb oundaryz one, as dis- cusseds hortly.T he distributiono f the motioni n time is of Studieso f plate boundaryz oness eekt o describet he kine- particulari nterestb ecauses teadym otionb etweenp latei nte- matics,o r motions,w ithin plateb oundaryz onesa s functions riors gives rise to episodicm otion at plate boundariesa, s of spacea nd time. The kinematic resultsa re then used to reflectedi n occasionalla rge earthquakeso r, in somec ases, draw inferencesa boutt he mechanicso f boundaryz onesa nd steadyc reep.T he relationb etweenp late motionsa nd earth- of large-scalep late motions.T heses tudiesc ombinev arious quakesi s complicateda nd poorly understooda nd hence typeso f data,s ummarizedin Figure3 . The datah aved iffer- forms a prime targeto f study. ent strengthsa nd limitations,s ampled eformationd ifferent-