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96 个结果
  • 简介:AsourceextentanalysisoftheLancangearthquake(Ms=7.6)of1988SI-HUAZHENG(郑斯华)JIANYANG(杨健)CenterforAnalysisandprediction,ChinaSeis...

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  • 简介:TheextensivedamagetobuildingscausedbytheNepalM_s8.1earthquakehasattractedmuchattentionbytheinternationalcommunity.AfterthepreliminaryscientificinvestigationsonthedifferentaffectedareasinNepal,theconstructionanddamagecharacteristicsoffivedifferenttypesofbuildingscommonlyexistinginNepalwerediscussedandthereasonsoftheirdisasterperformancewereanalyzed.Typesofbuildingsinvestigatedincludereinforcedconcrete(RC)framestructures,rubblestructures,brick-woodstructures,rawsoilstructures,andbrick-woodstructuresofhistoricbuildings.Inaddition,theweaklinksoftheseismicdesignwerepointedout,whichwasveryimportantforthepost-earthquakereconstructionandrecovery,andgaveapreliminaryexplanationsforthedamageexperienced.

  • 标签: Nepal EARTHQUAKE SEISMIC DAMAGE of BUILDING
  • 简介:Thepost-earthquakerapidaccurateassessmentofmacroinfluenceofseismicgroundmotionisofsignificanceforearthquakeemergencyrelief,post-earthquakereconstructionandscientificresearch.TheseismicintensitydistributionmapreleasedbytheLushanearthquakefieldteamoftheChinaEarthquakeAdministration(CEA)fivedaysafterthestrongearthquake(M7.0)occurredinLushanCountyofSichuanYa’anCityat8:02onApril20,2013providesascientificbasisforemergencyrelief,economiclossassessmentandpost-earthquakereconstruction.Inthispaper,themeansforblindestimationofmacroscopicintensity,fieldestimationofmacrointensity,andreviewofintensity,aswellascorrespondingproblemsarediscussedindetail,andtheintensitydistributioncharacteristicsoftheLushan'4.20'M7.0earthquakeanditsinfluentialfactorsareanalyzed,providingareferenceforfutureseismicintensityassessments.

  • 标签: Lushan EARTHQUAKE INTENSITY ASSESSMENT damage index
  • 简介:OnApril25,2015,aM_S8.1earthquakeoccurredinNepal.IntheTibetareaofChina,thisearthquakecausedheavycasualtiesanddamagetohousing,roads,communications,otherlifelineengineering,waterconservancyandotherinfrastructure.Thispaperintroducesthebasicsituationoftheearthquake,andbasedontheinvestigationandassessmentofseismicintensity,thedamageofthedisasterareaisanalyzed,andbuildingtypesanddamagetothelifelinesystemsandvariousindustriesaregiven.Throughtheanalysisofthecharacteristicsoftheearthquakedisaster,thispaperpointsouttheexistingproblemsinseismicfortification,andfinallyputsforwardproposalsforthepreventionandcontrolofearthquakegeologicaldisasters,scientificplanningfortherestorationandreconstruction,strengtheningearthquakepreventionanddisasterreductionpropaganda,improvingtheawarenessofearthquakepreparednessintheagriculturalandpastoralareas,strengtheningtheguidanceandsupervisionofhousingconstructioninruralareastoreducethecasualtiesandlosses,andpromotingtheharmoniousdevelopmentofeconomyinTibet.

  • 标签: 8.1级地震 西藏地区 震害特征 尼泊尔 地震地质灾害 防震减灾宣传
  • 简介:Inthispaper,basedonGansuDigitalSeismicNetworkdatasince1990,wecalculatedb-valueand⊿b-valueoftheneighborhoodareabeforethe2013Minxian-ZhangxianM_S6.6,earthquake.Theresultsshowthattheearthquakeoccurredatthemarginofthesignificantlylowerb-valueareainsoutheastofGansuandbeforetheearthquaketheneighborhoodareahadanobviouslyabnormal⊿b-value.Fromtheearthquakeandthespatialdistributionoflowb-value,theregionstillhasthepossibilityofgeneratingdangerousstrongearthquakes.

  • 标签: 数字地震台网 甘肃东南部 b值 异常 岷县 地震发生
  • 简介:2014年11月15日,在甘肃省白银市景泰县发生MS4.7地震,震源深度10km。在震中附近200km以内,甘肃省地震局共安装架设有14台各类形变观测仪器。本文通过对这些形变观测仪产出的分钟值观测资料做小波分析发现,在地震前1个月内共有11台(套)形变观测仪记录到了异常变化。其中:SSY、TJ、DSQ、SSQ型观测仪记录到异常的同步性非常好;CZB型观测仪记录到的异常比较乱,没有固定的规律。通过对这些异常变化的总结能够为地震预测提供一定的判断依据。

  • 标签: 景泰Ms4.7地震 小波分析 定点形变 异常变化
  • 简介:汶川Ms8.0级地震发生在青藏高原东缘著名的龙门山断裂带上,造成了中央断裂和前山断裂共约330kin的地震地表破裂带。初步研究表明,龙门山断裂带上大震复发可能属特征地震模式。结合龙门山断裂带的地震地质情况和汶川地震地表破裂带的基本参数综合分析,本文从地质学、地震学和GPS数据分析三个方面评估了龙门山断裂带的大震复发周期。结果表明,上述三种方法获得的龙门山断裂带Ms8.0级地震的复发间隔分别为:3185a、170(02264a和4310a,平均为3000a左右:Ms7.5级地震的平均复发间隔为1000a左右;Ms7.0级地震的平均复发间隔为500a左右。这些结果与其他学者的研究结果相比,相差不多,基本反映了龙门山断裂带的地震能量水平和累积速度。

  • 标签: 龙门山断裂带 汶川 大震 复发间隔
  • 简介:Complex time-space spreading and focal mechanism of the 1989 Batang earthquake swarm (M_=6.7)(程万正)(陈天长)Complextime-spacespre...

  • 标签: strong EARTHQUAKE SWARM time-space SPREADING source
  • 简介:BasedonthewaveformdataobservedbytheregionalseismicnetworkofGansuProvince,wecalculatedtheapparentstressof422earthquakeswithM_L≥2.0occurringinthesurroundingareaoftheMinxianearthquakefromJanuary2010toJuly2014andobtainedthetemporalandspatialvariationofapparentstressbeforeandaftertheMinxianearthquake.Resultsshowthat(1)thehighvalueofapparentstressofearthquakeswithM_L≥4.0wasconcentratedintheepicenterareabeforetheMinxianearthquakewhilethatofearthquakeswithM_L<4.0wasnot;(2)ApparentstressaroundtheepicenterareashowedanobviousincreasingprocessbeforetheMinxianearthquakeandtheincreasingprocesshascontinuedafterthemainshock,whichmeansthatthisstudyareaisstillinthedangerofstrongearthquakes.

  • 标签: 地震视应力 岷县 区域地震台网 地震前 波形数据 地震发生
  • 简介:IntroductionRegionalseismicitytriggeredbybigearthquakesaswellasattershocksinsourcezonecouldbedetectedduetothehighseismicmonitoringcapabilitytoday(Anderson,etal,1994;Bodin,Gomberg,1994;Caskey,Wesnousky,1997;Deng,Sykes,1996;Hill,etal,1993;King,etal,19...

  • 标签: Tangshan earthquake SEISMICITY COULOMB failure stress
  • 简介:TheregionaltectonicbackgroundandcharacteristicsofactivefaultsoftheYutianMS7.3earthquakeonFebruary12,2014arediscussedinthispaper.AftertheanalysisoftheepicenterareaoftheMS7.3earthquakein2014andthefocalmechanismsoftheformerstrongearthquakesaroundit,theauthorsdeducedthattheseismogenicfaultoftheMS7.3earthquakeistheeastbranchoftheAshikulefault.TheMS7.3earthquakein2014andtheMS7.3earthquakein2008aretwostrongearthquakeeventsonthedifferentsectionsoftheAltunTaghfault,wherethefaultbehaviorchangesfromsinistralsliptonormalfaultingbecauseoftheextensionaltaileffectsinthesouthernendoftheAltunTaghfault.ItisconcludedthatthetwoMS7.3earthquakeshavethesamedynamicsource,andtheMS7.3earthquakein2008promotedtheoccurrenceoftheMS7.3earthquakein2014.Finally,wecalculatetheCoulombstresschangetotheseismogenicfaultoftheMS7.3earthquakein2014fromtheMS7.3earthquakein2008usingthelayeredcrustmodel.TheresultalsoshowsthattheMS7.3earthquakein2008acceleratedtheoccurrenceoftheMS7.3earthquakein2014.

  • 标签: 区域构造背景 地震对 阿尔金断裂带 活动断层 发震断层 震源机制
  • 简介:江苏高邮、宝应Ms4.9级地震在极震区造成了数10间农村民居不同程度和不同方式的破坏,出现人员伤亡。震后对地震灾害现场进行震害调查与破坏原因研究,典型的震害特征包括砖砌体、砖木和砖混结构房屋局部倾倒、墙体贯通开裂、房顶瓦片掀翻和烟囱倒塌等。农村民居遭到破坏的主要因素包括:选址不当、施工质量较差、砂浆强度不够、缺少圈梁和构造柱等。同时,分析了竖向地震作用和鞭梢效应等地震效应,讨论了砖砌体和砖混结构抗震设计的加固方法和改善抗震性能的构造措施等,为农村民居的抗震设防和减轻震害损失等提供参考。

  • 标签: 高邮、宝应M_S4.9级地震 震害调查 破坏原因 竖向地震作用 鞭梢效应
  • 简介:EarthquakesofM_S5.6andM_S6.1occurredinYingjiang,YunnanonMay24andMay30,2014respectively.Inthispaper,weusethewaveformdatarecordedbymobileseismicstations(KAC)whichweresetupinthesourceareaaftertheYingjiangMS5.6earthquakeonMay24,2014tostudytheshear-wavesplittingcharacteristicsofYingjiangM_S6.1earthquakesequencewiththeSAMmethod.Theresultshowsthatpredominantpolarizationoffastshear-wavesbeforetheM_S6.1earthquakeisconsistentwiththedirectionofregionalprincipalcompressivestress,andpredominantpolarizationoffastshear-wavesbeforetheM_S6.1earthquakeshowbetterconsistencyandsmallerdispersioncomparedtoaftertheM_S6.1earthquake,andtheremaybeadeflectionforthefastshearwavespredominantpolarizationbetweentheM_S6.1earthquakesequenceandforeshocksequence.Wefoundthatthetime-delaysgenerallyexhibitedalowerlevelbeforetheM_S6.1earthquakeandarelativelyhighervalueaftertheM_S6.1earthquake.

  • 标签: 剪切波分裂 地震序列 波形数据 应力方向 前震序列 延迟时间
  • 简介:本文研究了1920年以来,云南地区M_s≥4.7级地震的时间序列及空间分布的特征标度。结果表明,当区内M_s≥4.7级地震在时间序列上出现我们定义的平静段和活跃段后,分别于418天和312天内即可能发生6级以上地震,对应率分别为71%和87%,1920年以来云南11次M_s≥6.8级地震前,出现活跃和平静特征标度的各5次。在空间上绝大多数(80%)大震震中处于我们所定义的长时间大范围空白缺震背景区或相对少震区内,仅少数(20%)位于4.7级以上地震相对密集区内或附近。4.7级以上地震上述时间序列及空间分布特征标度,可以作为云南6级,特别是6.8级以上地震中期或短期预测的判据和指标。同时可以看出,云南6级以上地震前,4.7级以上地震在时空演变上,经历了从无序到有序的演化过程。

  • 标签: 时间序列 空间分布 地震预报 云南省 地震空区
  • 简介:StaticCoulombstresschangeinducedbyearthquakeslipisfrequentlyusedtoexplainearthquakeactivitiesandaftershockdistribution.However,someparametersfortheCoulombstresscalculationareunabletobewellconstrainedfromlaboratoryexperimentsandfieldobservations.DifferentparametersmaydirectlyaffectthepatternofstaticCoulombstress.ThestaticCoulombstresschangesinducedbytheWenchuanearthquakecalculatedbysixresearchgroupsarenotconsistentwitheachother.Toinvestigatehowtheparametersaffectthecalculationresults,wechangetheparametersinturnthroughmodelingandcomparetheresultsofdifferentcalculationparameters.Wefindthatgravity,positionandstrikeofreceiverfaultshavelittleinfluenceoncoseismicCoulombstresscalculations,butotherparameterscanchangethevalueandsignoftheresultsinvariousdegreesespeciallyaroundtheearthquakeruptureplane.ThereforetheuncertaintyanalysisofstaticCoulombstresschangeinducedbyearthquakeshouldbetakenintoconsiderationintheearthquakehazardanalysis.

  • 标签: 不确定性分析 库仑应力 地震发生 应力变化 静态 汶川
  • 简介:OnJuly22,2013,theMinxian-ZhangxianM_S6.6earthquakeoccurredontheeastsegmentofLintan-Dangchangfault.TheanalysisofdigitalelevationandremotesensingimagingshowsthattheeastsegmentofLintan-Dangchangfaultisstillactiveandthemainthrustfeatureofthefaultswitchestoleftlateralslip.Withthefieldresearchofintensityanddamage,severalabnormalareasofdegreeⅧspreadintheisoseismallineofdegreeⅦandsomeabnormalareasofdegreeⅦspreadintheisoseismallineofdegreeⅥ.Theseabnormalareasaredistributedalongthehangingwallofthefaultinawidthof2km.TheanalysisbasedontheremotesensinganddigitalelevationmodelshowsthatthesegmentoftheLintan-DangchangfaultsouthofMinxianmainlyslipsinleftliteral.Thefaultmovementmadethesoilsoftinthefaultzone.Theearthquakemotionpropagatedalongthefaultzone.Thereforethestrongearthquakemotioncausedfoundationfailureinthesoftsoilalongthefaultzoneandtheabnormalintenseareasofdisasterformed.

  • 标签: 地震运动 岷县 数字高程模型 异常区分 机制 烈度
  • 简介:OnthebasisofthepreviousstudiesofthelayeredcrustalmodelintheYutianarea,combinedwiththefieldGPScontinuousobservationdata,weroughlyestimatetheviscouscoefficientofeachlayer.Withtheviscoelastichorizontallayermodel,wecalculatetheviscoelasticco-seismicCoulombstresschangecausedbytheYutianM_S7.3earthquakes2008and2014respectively.BasedontheCoulombstresschange,usingthecalculationmethodof"direct"aftershockfrequency,wecomeupwiththetheoreticalearthquakefrequencydirectlyrelatedtothemainshockandtheco-seismicCoulombstresschangeinthestudyarea.Thenweputforwardamethod,basedonthecomparisonoftheoreticalandactualearthquakefrequencyorthecomparisonbetweentheoreticalandpracticalearthquakefrequency-distancedecaycurvefittingresiduals,toestimatethemagnitudeofamaximumsequentearthquake,directlyrelatedtothemainshockco-seismicCoulombstresschange.Resultscalculatedbydifferentmethodsshowthatthemaximumfollow-upearthquakemagnitudecausedbythecoseismicCoulombstresschangeliesfromM_S7.2toM_S7.5followingYutianM_S7.3earthquakein2008;butthatofthe2014YutianM_S7.3earthquakeisM_S6.3.TheformerisveryclosetotheYutianM_S7.3earthquakein2014.Becauseofthesamemagnitude,relativelyclosespatialdistance,shorttimeinterval,thesameregionoftheexternalforce,thestrongcorrelationbetweentwoseismictectonicandaclearstressinteraction,wethusconsiderthatthetwoYutianM_S7.3earthquakesin2008and2014constituteapairofgeneralizeddoubleshocktypeearthquake.Thisisconsistentwiththesequencetypecharacteristicofpast"doubleshock"earthquakesintheregion.Inthispaper,theinfluenceofthemagnitudelowerlimitandtheb-valueintherelationshipofG-Rontheresultsisdiscussed.Asaresult,whentheviscoelasticcoseismicCoulombstressvariationisdetermined,thelowerlimitofmagnitudehaslittleeffectonthemaximumsequentearthquakemagnitude

  • 标签: 最大地震震级 库仑应力 应力变化 估计 黏弹性 地震频率
  • 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。

  • 标签: 青藏高原 震级 破裂带长度 不确定性分析