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简介：AMW6.4earthquakeoccurredinL'Aquila,centralItalyat1:32:42(UTC),April6,2009.WequicklyobtainedthemomenttensorsolutionoftheearthquakebyinvertingthePwaveformsofbroadbandrecordingsfromtheglobalseismographicnetwork(GSN)stationsusingthequicktechniqueofmomenttensorinversion,andfurtherinferredthatthenodalplaneofstrike132°,dip53°andrake-103°istheseismogenicfault.

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简介：PnarrivaltimedataarecollectedfromthebulletinsofbothnationalandregionalseismologicalnetworkinChina.ThesedataaretomographicallyinvertedtomapthelateralvariationandanisotropyofPnvelocityinthenortheasternmarginalregionofQinghai-Xizangplateau.TheaveragePnvelocityinthisregionis8.09km/s,beingalittlehigherthantheaverageforwholeChina.HighervelocityisfoundintectonicallystableQaidambasin,whilelowervelocityisseeninandaroundtectonicallyactiveShanxigraben.Theregionwherethe1920HaiyuangreatearthquakeoccurredshowsaslightlylowPnvelocity.Anoticeableresultisthat,differingfromthetectonicallycompressiveTianshanregion,wherePnvelocityislow,theQilianshanregion,wheretheNeotectonicdeformationisalsoprimarilycompressive,showshighPnvelocity.IntheuppermostmantlebeneaththeOrdosplateauPnvelocityisinhomogeneous,varyingfromhighervelocityinsouthwesternparttoloweroneinnortheasternpart.ThismaybeattributedtopossiblemovementoftheOrdosblock,astherearestrongearthquakesallaroundtheblock.

简介：Mostpublishedstudiesoninelasticearthquakeresponseofnon-symmetricbuildingsarebasedonsimplifiedinelastic,highlyidealizedmodels,whilegeneralconclusionsregardingtheinelastictorsionalresponseofmultistorybuildingarestilllacking.Thispaperaimstoprovideausefulcontributioninthestudyofthetorsionalresponseofrealirregularbuildings.Tothisaim,themanuscriptreportsthecomprehensivestudyontheseismicvulnerabilityofanirregularRCbuilding:thehospitalbuildingofAvezzano(L’AquilaItaly).Forthismulti-storybuilding,whichisirregularinbothplanandelevation,theapplicationofnonlinearstaticevaluationproceduresisbynomeansstraightforward.Thestudyproposesanonlinearstaticprocedurebasedonpushoveranalysisunderthemultimodaldistributionoflateralloadsandacapacityspectrummethod.Thispushoverprocedureaccountsformassdistribution,highermodescontributionandmode-shapescorrelation.Furthermore,duetoitsnon-iterativefeature,itavoidsproblemsofnon-convergenceandmultiplesolutionsoftheconventionalcapacityspectrummethod.Appliedtoarealcasestudy,theprocedureisusedtoinvestigate,ina3Dplanirregularbuilding,thesensitivityoftorsionalinelasticresponsetolateralforcedistribution,highermodescontribution,accidentaleccentricityandcontrolledpointformonitoringthetargetdisplacement.

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简介：Basedondatacollectedfromatemporalseismicnetwork,andinadditiontothedatafromsomenearbypermanentstations,weinvestigatethevelocitystructureandseismicityintheRongchanggasfield,wheresignificantinjection-inducedseismicityhasbeenidentified.First,weusereceiverfunctionsfromdistantearthquakestoinvertdetailed1-Dvelocitystructuresbeneathtypicalstations.Then,weusethedouble-differencehypocenterlocationmethodtore-locateearthquakesofthe2010ML5.1earthquakesequencethatoccurredintheregion.There-locatedhypocentersshowthatthe2010ML5.1earthquakesequencewasdistributedinasmallareasurroundingmajorinjectionwellsandclusteredmostlyalongpre-existingfaults.Majorearthquakesshowafocaldepthlessthan5kmwithadominantdepthof～2km,adepthofmajorreservoirsandinjectionwells.Wethusconcludethatthe2010ML5.1earthquakesequencemighthavebeeninducedbythedeepwellinjectionofunwantedwateratadepth～3kmintheRongchanggasfield.

简介：AM_L3.8earthquakeoccurredonFebruary23,2014inRongchangCounty,whichislocatedatthesouthernedgeoftheSichuanBasinintheborderareabetweenSichuanandChongqing.ThispaperpresentsresultsoffocalmechanismsolutionofthisearthquakeusingtheCAP(cutandpaste)methodbasedonbroadbandseismogramsrecordedbyregionalseismicstations.OurresultsshowthatthemomentmagnitudeisM_W3.09andfocaldepthis3km.ThehypocenterofthisearthquakeislocatedclosetoaburiedfaultintheLuoguangshananticline.Oilprospectinganddeepdrillingdataindicatethatthisburiedfaultisathrustfault,strikingSW230°,dippingNW45°,and1.7kmdeep.Therearesomeinjectionwellswithintheanticline,andsignificantinjection-inducedearthquakeswereobservedduringtheperiodsofinjectionofwastewaterintothedeepformationsthroughthosewells.ThebestdoublecouplesolutionoftheM_L3.8earthquakeis247°,48°and104°forstrike,dipandrate,respectively,foronenodalplane(and46°,44°and74°foranothernodalplane),whichisinagreementwiththegeometryoftheburiedfault.Therefore,weconcludethattheM_L3.8Rongchangearthquakeispossiblytheresultoffaultingalongtheburiedreversefaultinducedbywaterinjectionunderthecompressivestressregimeinthearea.

简介：The2009MW7.8Fiordland(NewZealand)earthquakeisthelargesttohaveoccurredinNewZealandsincethe1931MW7.8Hawke'sBayearthquake,1000kmtothenorthwest.InthispapertwotracksofALOSPALSARinterferograms(oneascendingandonedescending)areusedtodeterminefaultgeometryandslipdistributionofthislargeearthquake.Modelingtheeventasdislocationinanelastichalf-spacesuggeststhattheearthquakeresultedfromsliponaSSW-NNEorientatedthrustfaultthatisassociatedwiththesubductionbetweenthePacificandAustralianPlates,withobliquedisplacementofupto6.3m.ThisfindingisconsistentwiththepreliminarystudiesundertakenbytheUSGSusingseismicdata.

简介：Usingatimeseriesmethodthatcombinesboththepersistentscattererandsmallbaselineapproaches,weanalyzed9scenesEnvisatASARdataovertheL’Aquilaearthquake,andobtainedaShocke’sdisplacementfieldanditsevolutionprocesses.Theresultsshowthat:(1)EnvisatASARclearlydetectedthewholeprocessesofdisplacementfieldoftheL’Aquilaearthquake,anddistinctvariationsatdifferentstagesofthedisplacementfield.(2)Preseismiccreepdisplacement?displacementmutationwhenfaulting?constantlysloweddownaftertheearthquake.(3)Theareaofthestrongestdeformationandgroundrupturewasalow-lyingovaldepressionregiontothesoutheast.Surfacefaultingwithinazoneofabout22km914km,withanorientationof135°,occurredalongtheNW-strikingandSW-dippingPaganica-S.Demetrionormalfault.(4)Inanalyzinganareaofabout54km959km,boundedbynorth–southaxistotheepicenter,thedisplacementfieldhassignificantcharacteristicsofawatershed:westwardoftheepicentershowsupliftwithmaximumof130mminline-of-sight(LOS),andeastoftheepicenterwasaregionwith220mmofmaximumsubsidenceintheLOS,concentratingontherupturezone,themajorityofwhichformedinthecourseoffaultingandsubsequence.

简介：本文收集了青藏高原区7级以上以走滑为主的30个地震的地表破裂参数资料,拟合出了青藏高原区新的震级与破裂带长度统计关系式,并结合前人的统计关系式,分别通过破裂带长度估算震级,求出了估算震级与仪器震级的差值。同时将差值为正值（即估算震级偏大）的归为一类,差值为负值（估算震级偏小）的归为另一类,做了分析和对比。研究发现,差值为正值的地震所处的走滑断裂带一般位于一级块体或次级块体的边界断裂带上;差值为负值的地震所处的走滑断裂带大多位于一级块体或次级块体内部断裂带或断裂带的交汇处。基于上述分类的差异,作者对不同回归关系计算的差值数据进行了统计分析,分别给出了修正计算结果不确定性的参考值,为降低估算震级的不确定性提供了理论依据。

简介：本文简要介绍“数字福建”项目中防震减灾空间信息资源改造的设计方案

简介：建立“发育度”、“潜势度”、“危险度”、“危害度”等概念来描述地震地质灾害各影响因子、要素及可能的灾害危害程度,进而建立构成地震地质灾害层次分析的概念体系及地震地质灾害空间预警评估模型,将定性评估转化为定量评估进行初步研究。

简介：本文以长江中游地震带为研究区域，该区地震活动比较弱，发震构造不清晰，但人口、经济分布集中，中小地震往往会造成强烈的社会影响。自有记载以来，共记录到122次Ms≥4．7级的地震，最大的地震为1631年常德63/4级地震，在这样的区域进行地震危险性分析，依据构造特征和地震活动进行潜源划分的方法会带来较大的不确定性，为了更合理地评价其危险性，本文试图先在研究区内划分活动水平相当的等b值区域，然后利用空间光滑法计算各区的地震年平均发生率分布。结果显示，各分区内年平均发生率存在较大差异，年发生率分布图与现代和历史地震震中分布格局基本一致，为潜源区划分提供了一种量化的空间参考数据。

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。

简介：通过对近十余年发生在南疆几次强震的形变（应变）前兆对比观测资料进行分析，主要研究了异常时间进程和空间分布特征。

简介：人口是地震灾害的重要受灾体,准确的人口空间分布信息是防震减灾工作的重要依据。本文借助地理信息系统,将人口统计数据与高分辨率遥感数据相结合,应用基于居民地的人口数据空间化方法,模拟人口空间分布。首先根据城市人口—面积异速生长模型的分形几何意义,推导出城乡人口—面积统一模型;进而以2007年宁洱地震灾区为例,在建立居民地分类体系和遥感解译标志的基础上,目视解译获得准确的居民地信息;最后应用城乡人口—面积统一模型获得网格人口密度矢量数据。经检验,本文的结果达到了较高的精度。同时在人口数据空间化完成的基础上,以地震受灾人口估算为例,探讨了人口数据空间化在防震减灾中的应用。研究结果表明,基于网格人口矢量数据的受灾人口估算结果更能客观反映地震灾情,可以为防震减灾和应急救援工作提供可靠的依据。