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145 个结果
  • 简介:利用1999~2001中国大陆GPS最优综合观测解资料,借助改进的负位错模型,研究南北地震带及其邻近区域活动块体与其边界断裂的构造变形特征,获取高应力应变积累的闭锁区段及可能与强震孕育有关的背景信息.分析表明:祁连山断裂带与海原断裂和日月山断裂交汇区、日月山断裂南段与拉脊山断裂、宗务隆山-西秦岭北缘断裂交汇部位;盐源-丽江地块及NE向延伸至川滇交界的安宁河、则木河断裂交汇区及其临近区域;鲜水河至安宁河断裂北段以及与龙门山断裂交汇部位、滇西南边界的永德龙陵-澜沧-勐遮断裂及其北段与怒江断裂交汇区域可能具有高应变能积累背景.而阿尔金断裂中段、海原断裂东段、库玛断裂东端、红河断裂中东段与元谋-绿汁江断裂及小江断裂的交汇区域也可能存在一定程度的应变积累背景.

  • 标签: 南北地震带 GPS综合观测解 改进的负位错模型
  • 简介:IllustrationAllthedatainthiscatalogarechosenfromthe(PreliminarySeismologicalReportofChineseSeismicStations((Itsabbreviationis(MonthlyReport().ThecatalogincludestheeventsofM(4.7inandnearChinaandM(6allovertheworld.The(MonthlyReport(ismonthlycompiledbytheNinthSectionofInstituteofGeophysics,CSB.Theorigintimesofearthquakesinthecatalogadoptcoordinateduniversaltime(UTC)inaccordancewithinternationalconvention.Thelocationofeveryepicenterisexpressedbyitslatitudeandlongitude,atthesametimebythecorrespondinggeographicalregionproposedbyFlinnandEngdahl.Theregionalnamesareonlyforreferencesanddonotimplyanypoliticalsignificance.Thenumberofstationsusedandstandarddeviationarealsogiveninordertoillustratetheprecisionoflocation.

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  • 简介:福建省地震重点监视防御区城市防震减灾体系工程,在各部门的支持配合下,通过全局上下和各地市地震局的共同努力下,2001来取得实质性进展。加强领导,完善制度,精心组织项目实施,保证项目资金到位是非常重要的。

  • 标签: 地震重点监视防御区 城市防震减灾 进展
  • 简介:Morethanahalfofstrongearthquakesintheworldarelocatedinshallowdepthatthesubductingplateboundaryinsqueezedzones.Owingtothedifferenceinspeedbetweenthemovingseaplates,thestrainenergyisaccumulatedandreleasedcyclicallyinsqueezedzones.Severalmethodsweredevelopedtoanalyzethemedium-andshort-termpotentialofmainshocks.Thesemethodscanbeclassifiedinto(1)lessdatasystemsusingthetheoryofgreymodelforearthquakeprediction,(2)quasi-periodicsystemsusingearthquakeactivityanalysis,(3)systemsofgroupedactivityusingorderanalysis,and(4)nonlinearsystemsusingbackpropagation(BP)ofneuralnetworkforpredictionanalysis.Basedupontheseanalyticmethods,riskmapsforthepredictionofstrongearthquakescanbedrawnusingtherecordsofstrongearthquakesinTaiwanforthepast100years.Theseriskmapsinclude(1)aseismicriskmap,(2)alossriskmap,(3)ahazarddegreemap,and(4)alossdegreemap.Theseriskmapsmakeitpossibletodoamedium-termpredictionofmainshocksonthe10-yearscale.

  • 标签: Earthquake prediction Medium-and SHORT-TERM Main shock
  • 简介:OnOctober27,2001,alargeearthquakewithMs6.0,namedtheYongshengearthquake,occurredalongtheJinshajiangsegmentofChenghaifaultinYongshengCounty,YunnanProvince.ItisthelargesteventtooccuralongtheChenghaifaultinthelast200years.Theseismo-geologicalsurveyshowsthattheseismogenicfault,whichistheJinshajiangsegmentofChenghalfault,takesleft-lateralstrike-slipasitsdominantmovementpattern.Accordingtodifferencesinverticalmotion,motiontime,landformsandscales,theChenhalfaultcanbedividedintoeightsegments.TheJinshajiangsegmenthasaverticaldislocationrateof0.4mm/a,farlowerthanthemeanrateoftheChenghaifault,about2.0mm/a.It'sdeducedthatthetwosidesofJinshajiangsegment'stuck'tightlyandhinderedthestrike-slipoftheChenghaifault.ThestrongearthquakedistributionbeforethiseventshowsthattheJinshajiangsegmentwasintheseismicgap.TheChenghaifault,asaboundaryoftectonicsub-blocks,makestheNorthwestYunnanblockandtheMiddleYunnanblockmoveclockwise,andtheirmarginsmoveoppositelyalongtheChenghalfault.InthemotionprocessoftheChenghaifault,structuralhindranceandtheseismicgapofstrongearthquakesarepropitioustotheconcentrationandaccumulationofstructurestress.Asaresult,theYongshengMs6.0earthquakeoccurred.TheSujiazhuang-ShangangfusegmentissimilartotheJinshajiangsegmentwithalowverticalmotionrateof0.3mm/aandintheseismicgap.Soit'spostulatedthatthesegmentmaybecomeanewstructurehindrance,andtheYongshengMs6.0earthquakemaytriggertheoccurrenceoffuturelargeearthquakesalongthissegment.

  • 标签: 震源 地震事件 金沙江 云南
  • 简介:Inthispaperchangesinfocalmechanisms,parametersofwavespectra,andstressdropsfortheMS=5.0foreshockandMS=6.0mainshockinFebruary2001inYajiangCounty,Sichuan,andseismicityinepicentralregionarestudied.ComparisonoffocalmechanismsfortheYajiangearthquakeswithdistributionpatternsofaftershocks,thenodalplaneI,strikinginthedirectionofNEN,oftheYajiangM=5.0eventischosenasthefaultingplane;thenodalplaneII,strikinginthedirectionofWNW,oftheM=6.0eventasthefaultingplane.Thestrikesofthetwofaultingplanesarenearlyperpendiculartoeachother.ThelevelofstressdropsintheepicentralregionbeforetheoccurrenceoftheM=6.0earthquakeincreases,whichisconsistentwithincreaseofseismicityintheepicentralregion.TheratedecayoftheYajiangearthquakesequence,changesinwavespectraforforeshocksandaftershocks,andfocalmechanismsarecomplex.

  • 标签: 地震 序列特征 源参数 前震 余震 中国
  • 简介:TheYajiangearthquakesequencein2001,withthemajoreventsofMs5.1onFeb.14andofMs6.0onFeb.23,aresignificanteventsintheSichuanregionduringthelast13years.Eighty-eightearthquakesinthesequencewithatleast5distinctonsetparametersforeachrecordedbytheSichuanSeismicNetworkintheperiodofJan.1throughJune30,2001werechosenforthisstudy.TheeventsarerelocatedandthefocalmechanismisderivedfromP-waveonsetsfor13eventswithrelativelylargermagnitudes.Thefocaldepthofallearthquakesfallbetweenarangeof2kmto16km,withdominantdistributionbetween9kmto11km.Theforeshocks,theMs5.1earthquakeandtheMs6.0earthquakeandtheiraftershocksarealllocatedclosetotheZihefaultandthedominantepicentraldistributionisinNWdirection,identicaltothatofthefault.ThefracturesurfaceofthefocalmechanismisdeterminedinaccordancetothemasstransferorientationintherecentearthdeformationfieldintheYajiangregion.ThePaxesoftheprincipalcompressivestressinfocalmechanismsolutionsofthe13eventsshowbiggerverticalcomponents,andthehorizontalprojectiontrendingSE.Theearthquakesareofleft-lateral,strike-slipnormal,andnormalstrike-sliptypes.TherupturesurfaceofmostearthquakesstrikeNW-SE,dippingSW.Basedontheaboveinformation,weconcludethattheZihefaultthatcrossestheearthquakearea,strikingNWanddippingSW,istheseismogenicfaultfortheYajiangearthquakesequence.

  • 标签: 地震强度 破裂特征 焦点压力场 地震层断点 四川
  • 简介:Usingthe78focalmechanismsolutionsoftheforeshocks,mainshockandaftershocksoftheearthquakesequencefortheYao'anearthquake,thecharacteristicsofthefocalfaultsandstressfieldfortheearthquakesequenceareanalyzed.TheresultsshowthatthemainruptureplaneoftheYao'anearthquakesequenceisatectonicfaultwithN50°Wstrikeandsteepdipandallthemainshock,theforeshocksandthevastmajorityofaftershocksoccurredonthemainruptureplane.AtectonicfracturewithNNE-NEstrikealsoparticipatedindevelopmentprocessofthesequencedominatedbyprincipalcompressionalstresswithnearlyhorizontalorientationSSEisconsistentwiththeregionaltectonicstressfield.Inthesequencedevelopment,thestressfieldinthefocalregionwascomplexwithmultiaximuthsandmulti-actionmodelsandthefocalruptureshowedcomplexfeatureswithmulti-directionsandmulti-patterns.

  • 标签: 震源 断层 应力场 姚安地震 2001年 1月
  • 简介:TheinvestigationondamagestofrozensoilsitesduringtheWestKunlunMountainsPassearthquakewithMs8.1in2001showsthatthefrozensoilintheseismicareaiscomposedmainlyofmoraine,alluvialdeposit,diluvialdepositandlacustrinedepositwiththedepthvaryinggreatlyalongtheearthquakerupturezone.Thedeformationandruptureoffrozensoilsitesaremainlyintheformofcoseismicfracturezonescausedbytectonicmotionandfissures,liquefaction,seismicsubsidenceandcollapseresultingfromgroundmotion.Theearthquakefracturezonesonthesurfacearemainbrittledeformations,which,undertheeffectofsinistralstrike-slipmovement,arerepresentedbyshearfissures,tensionalcracksandcompressivebulges.Thedistributionandconfigurationpatternsofdeformationandrupturesuchasfissures,liquefaction,seismicsubsidenceandlandslidesareallrelatedtotheambientrockandsoilconditionsoftheearthquakearea.Thedistributionofearthquakedamageischaracterizedbylarge-scalerupturezones,rapidintensityattenuationalongtheQinghai-Xizang(Tibet)Highway,wherebuildingsdistributeandpredominanteffectofrockandsoilconditions.

  • 标签: 昆仑山垭口 地震 冻土 破坏特震 地表运动
  • 简介:BasedontheanalysisofcoseismicdeformationinthemacroscopicepicentralregionextractedbyDifferentialInterferometricSyntheticApertureRadar(D-InSAR),andcombinedwiththeseismicactivity,focalmechanismsolutionsoftheearthquakeandfieldinvestigation,thecharacteristicofcoseismicdeformationofMS=8.1westernKunlunshanPassearthquakein2001wasresearched.ThestudyshowsthatitsepicenterliesinthenortheastsideofHohSaiHu;andtheseismogenicfaultinthemacroscopicepicentralregioncanbedividedintotwocentraldeformationfields:thewestandeastsegmentswiththelengthsof42kmand48km,respectively.Thewholefaultextendsabout90km.Fromthedistributionofinterferometryfringes,thecharacteristicofsinistralstrikeslipofseismogenicfaultcanbeidentifiedclearly.Thedeformationsonbothsidesofthefaultaredifferentwithanobviouslyhighervalueonthesouthside.Inthevicinityofmacroscopicepicenter,themaximumdisplacementinlookdirectionisabout288.4cmandtheminimumis224.0cm;themaximumsinistralhorizontaldislocationofseismogenicfaultnearthemacroscopicepicenteris738.1cmandtheminimumis551.8cm.

  • 标签: INSAR MS=8.1 WESTERN Kunlunshan PASS EARTHQUAKE
  • 简介:TheHori’sinversemethodbasedonspectraldecompositionwasappliedtoestimatecoseismicslipdistributionontheruptureplaneofthe14November2001MS8.1KunlunearthquakebasedonGPSsurveyresults.TheinversionresultshowsthatthesixslidingmodelscanbeconstrainedbythecoseismicGPSdata.Theestablishedslipsmainlyconcentratedalongtheeasternsegmentofthefaultrupture,andthemaximummagnitudeisabout7m.Slipontheeasternsegmentofthefaultrupturerepresentsaspurelyleft-lateralstrike-slip.Sliponthewesternsegmentoftheseismicrupturerepresentsasmainlydip-slipwiththemaximumdip-slipabout1m.Totalpredictedscalarseismicmomentis5.196×1020N?m.Ourresultsconstrainedbygeodeticdataareconsistentwithseismologicalresults.

  • 标签: GPS测量 断层滑动 地震数据 昆仑山 估计 逆方法
  • 简介:AnM=6.0earthquakeoccurredonFebruary23,2001inthewesternSichuanProvince,China.Themacroseismicepicentersituatedinthehighmountain-narrowvalleyregionbetweenYajiangandKangdingcounties.Accordingtofieldinvestigationintheregion,theintensityofepicentralareareachedVIIIandtheareaswithintensityVIII,VIIandVIare180km2,1472km2and3998km2,respectively.TheisoseismalsaregenerallyinellipticshapewithmajoraxistrendingnearN-Sdirection.TheearthquakedestroyedmanybuildingsandproducedsomephenomenaofgroundfailureandmountainousdisastersintheareawithintensityVIII.Thiseventmayberesultedfromlong-termactivitiesoftheLitangfaultandYunongxifault,twomainfaultsinthewesternSichuan.Themovementsbetweenthemainfaultsmadethecruststressadjustedandconcentrated,andfinallytheearthquakeonasecondaryfaultintheblockreleasedaquitelargeenergy.

  • 标签: seismic INTENSITY isoseismal ground failure SEISMOGENIC
  • 简介:  IllustrationAllthedatainthiscatalogarechosenfromthe"PreliminarySeismologicalReportofChineseSeismicStations"(Itsabbreviationis"MonthlyReport").ThecatalogincludestheeventsofM≥4.7inandnearChinaandM≥6allovertheworld.The"MonthlyReport"ismonthlycompiledbvtheNinthSectionofInstituteofGeophysics,CSB.……

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  • 简介:  Illustration  Allthedatainthiscatalogarechosenfromthe"PreliminarySeismologicalReportofChineseSeismicStations"(Itsabbreviationis"MonthlyReport").……

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  • 简介:19949月16日东山海外73级地震前一左右,厦门台地倾斜E-W分量变发生严重畸变,正常年变规律图象明显被破坏,异常出现后11个月,东山海外发生强震。该现象可以作为闽粤近海强震的一个重要前兆指标

  • 标签: 地倾斜 年变畸变 东山海外地震
  • 简介:根据2014全球地震灾害资料并对比历年统计数据可知,当年度属于地震造成人员伤亡的轻灾年。本文总结了2014全球地震灾害的主要数据,对当年主要地震灾害进行了描述,发现抗震设防建筑在地震中受损较小,提高房屋的抗震能力能够有效地减少财产损失以及人员伤亡。同时,本文分析了2014度地震灾害的分布特征,以及多震地区的“活跃性”与“周期性”特征。

  • 标签: 2014年 全球 地震灾害
  • 简介:辽宁是历史地震资料比较缺乏的地区,深入研究历史疑难地震,尤其是确认一些破坏性地震,对补充已有的地震目录和开展地震预测及工程场地地震安全性评价有重要作用。在历史地震研究中认真考查,论证已有的地震史料是最主要的手段和方法。但是若能在此基础上,利用现代地震资料,按"地震重复"发生理论反推一些历史上可能存在的破坏性地震,也可以认为是对历史地震研究方法的一种补充。按照这一思路,本文在进一步分析地震史料的基础上,通过与现代地震活动图像和大地震震害现象的对比,确认辽宁地区15094月21日的地震是一次破坏性地震,并对155210月27日的地震做了讨论。

  • 标签: 历史地震 地震考证 辽东湾 辽阳地区