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。

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

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

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

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简介：给出了中国数字地震台网（ＣＤＳＮ）兰州台数字化地震记录在１９９５年７月２２日永登５．８级地震前后Ｐ波出射角与方位角的异常变化：主震前数月出射角出现明显上升异常变化，方位角出现明显下降异常变化。探讨了利用出射角和方位角异常进行大地震预报的可能途径和方法。

简介：正Theauthorsthankthediscusserforhisinterestandcarefulreviewofthepaperandhisvaluablecomments.Theyalsowelcomethisdiscussion,becauseitgivestheauthorstheopportunitytoclarifyseveralpointswhichwerenotexplainedinsufficientdetailinthepaper,due

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.

简介：AnanalyticalsolutionforscatteringofplanePwavesbyasemi-cylindricalhillwasderivedbyusingthewavefunctionexpansionmethod,andconvergenceofthesolutionandaccuracyoftruncationwereverified.Theeffectofincidentfrequencyandincidentangleonthesurfacemotionofthehillwasdiscussed,anditwasshownthatahillgreatlyamplifiesincidentplanePwaves,andmaximumhorizontaldisplacementamplitudesappearmostlyattheinclinedincidenceofwaves,whicharelocatedatthehalf-space;andmaximumverticaldisplacementamplitudesemergemostlyattheverticalincidenceofwaves,whicharesituatedatthehill.

简介：Thispaperreviewstherecentprogressinthestudiesofexperimentalrockmechanicsandtectonophysicsconcern-ingseismologyandphysicsoftheEarth'sinteriorinChina.Theprogressispresentedinthefollowingaspects:a)Alotofresultsofexperimentandnumericalsimulationenrichourknowledgeofthebrittlefracturingprocessundertheconditionwithheterogeneityinmaterialandstructure;b)Somenewresultsonfrictionalbehaviorofnon-homogeneousfaultsrevealthecomplexityoffaultingbehavior;c)Somenewresultsonthebrittle-plastictran-sitionandplasticflowareobtained;especiallytheimportantprogressisobtainedontheologicalpropertiesofrocksinthelowercrustandtheuppermantle;d)Alotofexperimentalresultsareobtainedonrockphysicsathightem-peratureandpressureandhavebeenusedinstudyofmaterialcompositionandstate.TheseresultsprovideusefulinformationforunderstandingthephysicalpropertiesanddeformationmechanismsofmaterialoftheEarth'sinte-riorandearthquakephysics.

简介：DiffractionofplanePwavesaroundanalluvialvalleyofarbitraryshapeinporoelastichalf-spaceisinvestigatedbyusinganindirectboundaryintegralequationmethod.BasedontheGreen'sfunctionsoflinesourceinporoelastichalf-space,thescatteredwavesareconstructedusingthefictitiouswavesourcesclosetotheinterfaceofthevalleyandthedensityoffictitiouswavesourcesaredeterminedbyboundaryconditions.Theprecisionofthemethodisverifiedbythesatisfactionextentofboundaryconditions,andthecomparisonbetweenthedegeneratedsolutionsandavailableresultsinsingle-phasecase.Finally,thenatureofdiffractionofplanePwavesaroundanalluvialvalleyinporoelastichalf-spaceisinvestigatedindetailthroughnumericalexamples.

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.

简介：本文结合柴家峡水电站坝址区的地震地质环境、历史地震特征以及场地条件，采用考虑地震分布时空不均匀性的综合概率法，对场区进行了地震危险性分析，在此基础上给出了坝址区５０年超越概率６３．２％、１０％、２％三个概率水准的设计地震动参数，为大坝的抗震设计和安全运营提供了依据。

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.

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.

简介：本文通过对当前我国农村住宅建设中存在的诸多问题的阐述,从中分析农村住宅抗震性能差的原因,并提出自己的观点、建议。

简介：本文分析了台湾恒春海外的一次地震的记录波形的P波的主要特征。首先对其首波PN进行分析,结果表明其线性关系较好,计算出的速度值与华南地区近震走时表中所用的地壳模型中的速度值一致。其次对其PN波的续至波进行分析,发现该处的地震其射线穿过台湾岛后的地震记录波形明显与没有穿过台湾岛的不同,即没有穿过台湾岛的地震记录波形中首波震相之后明显存在有另一组震相,而穿过台湾岛后的地震记录波形则没有或不明显。该组震相最明显特征是它与首波的到时差随震中距的加大而减小,据此,作者认为它可能是一组波,即地壳内的双程反射波,表明该处有低速层存在。分析结果表明,台湾海峡南部即福建省的东山海外地区及泉州、漳州、永安地区的下方有一低速层存在。

简介：为P三角洲效果和增强的具体成员的hysteretic行为的修改精力平衡方程财务被导出。结构的部件的减少的hysteretic性质由于联合僵硬和力量，降级和拧的效果，和抑制的hysteretic被利用塑料精力和地震输入精力修正以一种简单方式考虑因素。有预先选择的收益机制，在无弹性的范围的结构的精力平衡被考虑。P三角洲效果被把严肃负担的外部工作加到相等的惯性力量的工作并且等同全部的外部工作到修改塑料精力在导出的方程包括。地震精力输入到多自由(MDOF)的度系统被使用形式的精力分解接近。基于精力的底砍系数借助于闲差事分析和有故事的不同数字的几个RC框架的非线性的时间历史(NLTH)分析被验证。框架的NLTH分析被与土耳其语的地震设计的相关要求编码的有弹性的设计加速光谱和圆满持续时间/振幅使用十放大地面运动兼容机的时间历史执行。在基于精力的底之间的观察关联砍力量系数和平均的底砍NLTH分析的力量系数在非线性的底的评价提供一颗合理信心砍由使用导出的方程的框架的力量能力。

简介：Wepresentanexampleofusingconverted-wavesforcharacterizingonshoregasreservoirsintheOrdosbasininNorthwestChina.TheOrdosbasinisthelargestgasprovinceinChina.Themaingasreservoirs(about3300mindepth)areinupperPaleozoicsandstonethathasloworreversedP-waveimpedanceandisimmediatelyaboveacoalseam.ThismakesitverydifficulttoimagethegasreservoirsusingconventionalP-wavedata.Analysisofcore,logandVSPdatashowsaweakPPreflectionbutarelativelystrongPS-convertedwavereflection,orbothstrongPP-andPS-reflectionsbutwithoppositepolarityfromthegasbearingsands,whichindicatesthepotentialofusingPS-wavestoimagethegasreservoirsintheOrdosbasin.Subsequently,thirteenseismiclineswereacquired,processedandinterpretedtoverifythePP-andPS-responses,andtwocorrespondingattributes(PP-andPS-amplituderatioandpolarityratio)areusedtomapthereser-voirsthroughjointPPandPSanalysis.

简介：基于大圆弧假定,利用傅立叶-贝塞尔(Fourier-Bessel)级数波函数展开法,给出了含圆弧形沉积的楔形空间对平面P波的散射解析解。为方便构造地表面引起的散射波场,本文利用2个大圆弧面来模拟地表面,由连续性边界条件建立方程并求解得出该问题的解析解。算例结果表明,楔形空间沉积附近地表的动力响应特征依赖于入射波频率、入射角度、沉积内外介质特性与楔形夹角等因素,且位移放大效应较半空间情况更为显著。