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61 个结果
  • 简介:Inthispaper,wedeterminedanearthquakesequencelocationintheXingfengjiangareafromJune,2007toJuly,2014andthe3DP-wavevelocitystructurebyasimultaneousinversionmethod.Onthatbasis,westudiedtheoccurrencefeaturesofactivetectonicsandtheearthquakesourcemechanism.Theresultsshowthatthereservoirfracturesystemhasatendencytoincreasewithgradualdepthfromsoutheasttonorthwest,consistentwithgravitationalfieldresearchresults.Thereare4highvelocityzones(HVZ)underthedepthofthe7km-12kmcrustbetweentheXinfengjiangReservoirdamandXichangDistrict,Dongyuan.ThemaxvelocityofthebiggestHVZwhichisunderXichangis6.3km/s.Underthereservoirdamthereisastrongtectonicdeformationzone,asthecenterexitRenzishifault(F2),Nanshan-Aotoufaults(F4),Heyuanfault(F1)andShijiao-Xingang-Baitianfault(F5),7earthquakeswithML≥5.0(includingM6.1inMarch,1962)occurredatthehighgradientzoneoftheHVZⅢandHVZⅣedgewhichhasbeenunderthereservoirdamsince1960,withrelativityenergyreleasingmorethoroughly.ModerateseismicactivityoccurredattheHVZⅠedgewhichhasbeenunderXichangsince2012,andisadangerzoneforM5.0earthquakesinthefuture.

  • 标签: P-WAVE velocity STRUCTURE Active TECTONICS SIMULTANEOUS
  • 简介:当时,本地联合不稳定性将发生吸收边界状况和地波浪方程的数字计划允许精力自发地进入计算领域。也就是说,二个计划支持普通波浪解决方案,组速度指了进计算域。消除联合不稳定性的本地人的钥匙是避免如此的波浪答案。为块团在2D波导的P-SV波浪运动的有限元素模拟,为高顺序的稳定的实现的一条途径多播送的公式被提供。与一个一致矩形的网孔,它被证明并且验证那高周波的本地联合不稳定性能被设置等于或比\大的元素尺寸的比率消除(\sqrt2\)乘到S波浪速度的P波浪速度的比率。这些结果能为发另外的吸收边界条件导致的不稳定性问题是珍贵的。

  • 标签: 多次透射公式 P-SV波 有限元模拟 耦合失稳 波导 二维
  • 简介:Athree-dimensionalrigidbodyontheshapeofaparallelepipedismodelledinordertorockonasideoravertexofthebase,inordertoevaluatetheseismicresponseofrigidblockslyingonahorizontalsupport.Thecenterofmassofthebodyisconsideredaseccentricwithrespecttoitsgeometriccenter.Asseismicinput,threeItalianrecordedaccelerograms,withdifferentspectralcontent,areused.Thestudyismainlyconductedtohighlightthedifferencesbetweentheseismicresponseof2Dand3Dmodelsofrigidblocks,withtheaimtounderstandif,insomecases,theuseofthe3Dmodelofrigidblockisrequiredtoobtainsaferresults.Infact,theoutcomesshowthatinsomerangesofthegeometricalandmechanicalparametersthatcharacterizetheexcitationandthebody,atwo-dimensionalmodel,whichisnotabletoconsiderthe3Drockingonavertex,canprovideunsaferesults.Inparticular,itisfoundthattheoverturningprocessofthethree-dimensionalblockcanoccurunderexcitationswhicharelowerthanthosewhichoverturnacorrespondingtwo-dimensionalblock.

  • 标签: SEISMIC EXCITATION 3D RIGID BLOCK rectangular
  • 简介:AppendixA:Thederivationofequation()InFourierdomain,2(x)=2x2istransformatedintod2(kx)=-k2x(A1)Whenequation(3)isnumericalyc...

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  • 简介:Adetailthree-dimensionalPwavevelocitystructureofBeijing,TianjinandTangshanarea(BTTarea)wasdeterminedbyinvertinglocalearthquakedata.Intotal16048Pwavefirstarrivaltimesfrom16048shallowandmid-depthcrustalearthquakes,whichoccurredinandaroundtheBTTareafrom1992to1999wereused.ThefirstarrivaltimesarerecordedbyNorthernChinaUnitedTelemetrySeismicNetworkandYanqing-HuailaiDigitalSeismicNetwork.Hypocentralparametersof1132earthquakeswithmagnitudeML=1.7~6.2andthethree-dimensionalPwavevelocitystructurewereobtainedsimultaneously.TheinversionresultrevealsthecomplicatedlateralheterogeneityofPwavevelocitystructurearoundBTTarea.Thetomographicimagesobtainedarealsofoundtoexplainotherseismologicalobservationswell.

  • 标签: 京津唐地区 地震波 P波速度结构 数字遥测地震台网 地震观测 地震活动性
  • 简介:StudyoncorrelativityamongcapacitydimensionD0,infor-mationdimensionD1,algorithmiccomplexityC(n)andbValueWEI-BINHAN(韩渭宾),GUI-X...

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  • 简介:The2008Wenchuanearthquake,amajorintraplateearthquakewithMw7.9,occurredontheslowlydeformingLongmenshanfault.Tobetterunderstandthecausesofthisdevastatingearthquake,weneedknowledgeoftheregionalstressfieldandtheunderlyinggeodynamicprocesses.Here,wedeterminefocalmechanismsolutions(FMSs)ofthe2008Wenchuanearthquakesequence(WES)usingbothP-wavefirst-motionpolaritydataandSH/Pamplituderatio(AR)data.AsP-wavepolaritiesaremorereliableinformation,theyaregivenpriorityoverSH/PAR,thelatterofwhichareusedonlywhentheformerhaslooseconstraintontheFMSs.Wecollectdatafromthreecategories:(1)permanentstationsdeployedbytheChinaEarthquakeAdministration(CEA);(2)theWesternSichuanPassiveSeismicArray(WSPSA)deployedbyInstituteofGeology,CEA;(3)globalstationsfromIncorporatedResearchInstitutionsforSeismology.Finally,129eventswithmagnitudeoverMs4.0inthe2008WESareidentifiedtohavewell-constrainedFMSs.Amongthem,83arewellconstrainedbyP-wavepolaritiesonlyasshownbyCaietal.(EarthqSci24(1):115–125,2011),andtherestofwhicharenewlyconstrainedbyincorporatingSH/PAR.BasedonthespatialdistributionandFMSsoftheWES,wedrawfollowingconclusions:(1)theprinciplecompressionaldirectionsofmostFMSsoftheWESaresubhorizontal,generallyinagreementwiththeconclusiongivenbyCaietal.(2011)butwithafewmodificationsthatthecompressionaldirectionsareWNW–ESEaroundWenchuanandENE–WSWaroundQingchuan,respectively.ThesubhorizontalcompressionaldirectionalongtheLongmenshanfaultfromSWtoNEseemstohavealeftlateralrotation,whichagreeswellwithregionalstressfieldinvertedbyformerresearchers(e.g.,Xuetal.,ActaSeismolSin30(5),1987;ActaGeophysSin32(6),1989;Cuietal.,SeismolGeol27(2):234–242,2005);(2)theFMSsoftheeventsnotonlyreflectedtheregionalstressstateoftheLongmenshanregion,butalsowereobviouslycontrolledbythefaultstosomeextent,whichwaspointedou

  • 标签: 地震序列 震源机制解 P波初动 振幅比 汶川 极性
  • 简介:事件波浪的明显的速度是为与理论方法模仿旋转地面运动的一个重要参数,但是当仅仅有单个record.This时,纸在一块多层的各向同性的橡皮基于elastodynamic理论讨论一个P-SV比率方法,有效地对估计困难在SMARTI的四地震的明显的速度穿的半space.The与这method.The结果被计算接近使用旅行时间analysis.Furthermore的一个方法,因素

  • 标签: 速度估计 SV 弹性半空间 地震记录 动力学理论 入射角
  • 简介:Basedonwaveformdata,severalmethodstodeterminefocalmechanismsofsmallearthquakesweredevelopedsince1980.Kisslinger(1980)andJulian,Foulger(1996)proposedanapproachtodeterminesolutionbyusingamplituderatioofPandSwave.Schwartz(1995)devisedamethodtodeterminesolutionsbytheuseofpolaritydataandamplitudesofseismogramenvelopes.Amplitudesofshortperiodseismicwavespropagatinginaninhomogene-ousmediumaresensitivetothevariationinvelocityandQstructure.Nakamura,etal(1999)tookmediuminhomo-geneityintoaccountindeterminingfocalmechanismsofsmallearthquakesusingwaveformdata.Ifthelocationsofsmallearthquakesareconcentratedinasmallregion,wecanassumethattheraypathsfromtheeventstoagivenstationarealmostthesame.SoPandSwaveattenuationsareindependentofeventlocations.Inthiscaseitiscon-venienttodeterminefocalmechanismsoftheseeventsbyusingshortperiodPandSwavedataj.Focalmechanismsolutionsofsmallearthquakesin5regions,i.e.,Rongchang,Mabian-Muchuan,Ya¢an,BaoxingandMianzhu,whicharecoveredbytheChengduTelemeteredNetwork,areobtainedbyanalyzingthePpolarityandshortbodywaveamplitudedatarecordedinthenetworksince1992.AccordingtothemethodproposedbyGephartandForsyth(1984),basedonwelldeterminedfocalmechanismsolutionsin15sub-zonesofSichuanandYunnanarea,threeprincipalstresstensorss1,s2,ands3,insteadofaveragesofP,B,andTaxisofthesolutions,aredeterminedtorepresenttheregionalstressfielddistribution.

  • 标签: Sichuan-Yunnan area FOCAL mechanism stress field
  • 简介:AnanalyticalsolutionforscatteringofplanePwavesbyasemi-cylindricalhillwasderivedbyusingthewavefunctionexpansionmethod,andconvergenceofthesolutionandaccuracyoftruncationwereverified.Theeffectofincidentfrequencyandincidentangleonthesurfacemotionofthehillwasdiscussed,anditwasshownthatahillgreatlyamplifiesincidentplanePwaves,andmaximumhorizontaldisplacementamplitudesappearmostlyattheinclinedincidenceofwaves,whicharelocatedatthehalf-space;andmaximumverticaldisplacementamplitudesemergemostlyattheverticalincidenceofwaves,whicharesituatedatthehill.

  • 标签: 地震 震波 分散度 有限元分析
  • 简介:Thispaperreviewstherecentprogressinthestudiesofexperimentalrockmechanicsandtectonophysicsconcern-ingseismologyandphysicsoftheEarth'sinteriorinChina.Theprogressispresentedinthefollowingaspects:a)Alotofresultsofexperimentandnumericalsimulationenrichourknowledgeofthebrittlefracturingprocessundertheconditionwithheterogeneityinmaterialandstructure;b)Somenewresultsonfrictionalbehaviorofnon-homogeneousfaultsrevealthecomplexityoffaultingbehavior;c)Somenewresultsonthebrittle-plastictran-sitionandplasticflowareobtained;especiallytheimportantprogressisobtainedontheologicalpropertiesofrocksinthelowercrustandtheuppermantle;d)Alotofexperimentalresultsareobtainedonrockphysicsathightem-peratureandpressureandhavebeenusedinstudyofmaterialcompositionandstate.TheseresultsprovideusefulinformationforunderstandingthephysicalpropertiesanddeformationmechanismsofmaterialoftheEarth'sinte-riorandearthquakephysics.

  • 标签: 脆性断裂 断层断裂 塑性流动 岩石物理学 地震机理 地震学
  • 简介:DiffractionofplanePwavesaroundanalluvialvalleyofarbitraryshapeinporoelastichalf-spaceisinvestigatedbyusinganindirectboundaryintegralequationmethod.BasedontheGreen'sfunctionsoflinesourceinporoelastichalf-space,thescatteredwavesareconstructedusingthefictitiouswavesourcesclosetotheinterfaceofthevalleyandthedensityoffictitiouswavesourcesaredeterminedbyboundaryconditions.Theprecisionofthemethodisverifiedbythesatisfactionextentofboundaryconditions,andthecomparisonbetweenthedegeneratedsolutionsandavailableresultsinsingle-phasecase.Finally,thenatureofdiffractionofplanePwavesaroundanalluvialvalleyinporoelastichalf-spaceisinvestigatedindetailthroughnumericalexamples.

  • 标签: 平面P波 半空间 衍射 冲积 边界积分方程法 河谷
  • 简介:本文针对国家台网速报面波震级测定时间偏长和中深源地震震级速报有一定偏差的问题,采用IASPEI推荐的宽频带体波震级mB及宽频带P波矩震级MWP对2009-2013年国家台网地震速报的大震进行了对比分析.对于经过转换成MW后的mB和MWP震级来说,其结果均与我国速报地震发布的震级M有一定的偏差,一般表现为偏小.其中,对于6.0-6.9级地震,mB偏差相对较小,但离散度相对较大(整体偏差要比平均偏差大不少);对于7.0-7.9级地震,MWP偏差相对较小;而对于8.0级以上地震,由于震级饱和等原因,mB偏差较大,但MWP偏差相对较小,一般主要表现为偏小.总体来说,MW(MWP)的稳定性要比MW(mB)更好一些(线性回归的相关系数更大,标准误差更小).对于综合mB和MWP震级来说,由于采取分段平均的方法,结果的稳定性有了一定的提高,但较大地震仍以偏小为主,如果在综合震级MP,上加0.2,则可以得出与M震级较为接近的结果.通过MW(mB)、MW(MWP)、MP(M)、M与MW(GCMT)的对比,可以验证综合标准震级MP(M)和国家台网速报震级M具备一定的可信度,而MP(M)可作为P波快速测定的震级,所以用MP(M)作为大震速报初报震级,在某种程度上是可行的.

  • 标签: P波震级 体波震级mB 宽频带P波矩震级MWP 标准震级M
  • 简介:Theconventionalpseudo-staticapproachoftenneglectstheeffectoftheverticalseismicaccelerationonthestabilityofaslope,butsomeanalysesunderplane-strain(2D)conditionsshowasignificanteffectontheslopestability.Thepurposeofthisstudyistoinvestigatetheeffectoftheverticalaccelerationonthesafetyofthree-dimensional(3D)slopes.Inthestrictframeworkoflimitanalysis,a3Dkinematicallyadmissiblerotationalfailuremechanismisadoptedherefor3Dhomogeneousslopesinfrictional/cohesivesoils.Asetofstabilitychartsispresentedinawiderangeofparametersfor3Dslopesundercombinedhorizontalandverticalseismicloadingconditions.Accountingfortheeffectsoftheverticalseismicacceleration,thedifferenceinsafetyfactorsfor3Dslopescanexceed10%,whichwillsignificantlyoverestimatethesafetyofthe3Dslopes.

  • 标签: 边坡稳定性 三维运动学 地震加速度 垂直加速度 拟静力法 平面应变
  • 简介:Aftershocksofthe2011Tohoku-Okigreatearthquakehaveawiderangeoffocaldepthsandfaultplanemechanisms.Weconstrainthefocaldepthsandfocalmechanismsof69aftershockswithMw[5.4bymodelingthewaveformsofteleseismicPanditstrailingnear-surfacereflectionspPandsP.Wefindthatthe‘‘thrustevents’’arewithin10kmfromtheplateinterface.Thedipanglesofthesethrusteventsincreasewithdepthfrom*5°to*25°.The‘‘non-thrustevents’’varyfrom60kmaboveto40kmbelowtheplateinterface.Normalandstrike-slipeventswithintheoverridingplatepointtoredistributionofstressfollowingtheprimarygreatearthquake;however,duetothespatiallyvariablestresschangeintheTohoku-Okiearthquake,anunderstandingofhowthemainshockaffectedthestressesthatledtotheaftershocksrequiresaccurateknowledgeoftheaftershocklocation.

  • 标签: 震源深度 震源机制 远震P波 余震 东北 建模
  • 简介:AmodelofseismicitywithfractalstructuresandapreliminarydiscussionontherelatiobetweenDandbvalueHat-KunJIANG(蒋海昆)andShou-ZhongDI...

  • 标签: 守中
  • 简介:Preliminaryresultof3DgravitationalforwardcalculationstudyinBohaiSeaGUANGXIALIU1)(刘光夏)WENJUNZHAO2)(赵文俊)WENJUREN1)(任文菊)XIU...

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