简介:一、地震基本参数表1 地震基本参数表发震时间年月日时分秒震 中 位 置微 观宏 观东经北纬东经北纬参考地名震级(MS)震源深度(Km)震中烈度 地震类型 1975042504061781182°256°1183°256°德化雷峰3289Ⅳ主震型 按微观震中定位,应在德化佛岭乡附近,宏观震中位于其东面10公里左右的雷峰乡附近。本次地震的震级为全省测定的平均数ML。二、地震烈度分布据调查,地震时有感人数较多的为雷峰乡一带,约占调查人数的20%左右,其它地点,约在10%以下,有的只是个别人有感。故圈定雷峰附近为震中区,烈度为Ⅳ度。地震时人们先闻到地声似闷雷呼呼响,后感觉到木板墙、床、门在摆动。本次
简介:Completerecordsofmorethan3,000earthquakeeventsintheShanxi,WenzhoureservoirearthquakesequencewererecordedfromAugusttoNovember,2014bythehigh-density,high-resolutionmonitoringstationsoftheZhejiangRegionalDigitalSeismicNetworkandthereservoirearthquakemonitoringnetwork,withamaximummagnitudeofM4.2.Basedon3-Depicenterlocation,focalmechanismsolutions,andincombinationwiththegeologicalandtectoniccharacteristicsofthereservoirarea,theearthquakesequenceisdiscussedinthispaper.ThelinearfittingoftheHypoSATlocationresultsshowthatthemainshockoccurredintheNWtrendingfaultandtheearthquakesequenceisconcentratedinbandsalongtheactivefaults,withastrikeof305°,dippingSWwithdipangleof85°.ByusingP-wavefirstmotionsymbols,weobtainedtheaveragefocalmechanismofM≥3.5earthquakes,withastrike308°anddip84°fornodalplaneII.Thefieldgeologicalsurveyandresearchshowthatthestrike,dipandrakeofnodalplaneIIareroughlyconsistentwiththeoccurrenceoftheShuangxi-Jiaoxifault.ThecomprehensiveanalysisrevealsthattheNW-trendingShuangxi-Jiaoxifaultistheseismogenicstructureoftheearthquakes.
简介:6.5Ludian地震引起了617的一个死亡人数的2014大小,许多山崩和几万座折叠大楼。评估损坏到大楼的地调查在地震的出现以后立即被执行。严重地损坏的aseismic大楼,基本上在Longtoushan镇的闹市区被观察,小心地与目的一个一个地被检验改进设计代码。这份报纸总结在两个观察到调查aseismic大楼的损坏结构、本地的层次。一个普通失败模式被观察aseismic大楼的那个大多数例如RC框架结构和限制石工技术结构,被严重损坏或第一个故事的完全的倒塌同样破坏。相关充分的理由运动,在附近的车站被记录,有不到20s的短持续时间但是很大的针网阵列直到1.0g。基于新设计,代码仍然没能完成设计的RC框架为强壮的列指向,弱横梁。典型本地失败细节,与在RC列和填入墙之间并且在构造上的列和石工技术墙之间的相互作用有关,与初步的分析被总结。
简介:一、地震基本参数表1 地震基本参数表发震时间年月日时分秒震 中 位 置微 观宏 观东经北纬东经北纬参考地名震级(MS)震源深度(Km)震中烈度 地震类型 19950225111508118°42′24°22′晋江海外5310Ⅵ主余震型 本次地震的宏观震中,未作推断,从图面的合理性考虑,应在微观震中的北偏西10余公里处。二、地震烈度分布由于震中位于海域,离震中最近的金井围头也有20公里左右。在所有的现场调查点中,最高烈度值只有Ⅴ度,故仅勾划出一条Ⅴ度等震线(图21-1)。图21-1 1995年2月25日晋江海外地震等震线图Ⅴ度区:Ⅴ度等震线在惠安的辋川、斗尾一带入海,向西南,经过南安的洪濑,安
简介:AnM_S7.3earthquakeoccurredonFebruary12,2014inYutianCounty,XinjiangUygurAutonomousRegion,whichwasfollowedbyaseriesofaftershocks.ThispapercalculatesthedepthoftheM_S7.3earthquakesequencebyusingthedeterministicapproachwiththeseismicphasedatafromthecatalogdatabaseoftheChinaEarthquakeNetworksCenter,combinedwithoriginalseismicwaverecordsfromtheDigitalSeismicNetworkCenteroftheEarthquakeAdministrationofXinjiangUygurAutonomousRegion.
简介:TheFebruary12,2014,MS7.3,earthquakeinYutian,Xinjiang,China,occurredasaresultofshallowstrike-slipfaultinginthetectonicallycomplexregionofthenorthernTibetanPlateau,withadepthof17km.ThisearthquakeoccurredseveralhundredkilometersnorthoftheconvergentIndia-Eurasiaplateboundary.TheepicenterlocationoftheYutianearthquake,36.1°N,82.5°E,is110kmnorthofYutianCounty,HotanPrefecture.AlargenumberofaftershocksfromML2.0toML3.0occurreduntil12:00oclock,February23,2014andthelargestaftershock,MS5.7,occurredat17:24p.m.,February12,2014.ThebandhvalueofYutiansequenceare0.70and1.29,respectively.ThewaitingtimemethodrevealsthatthestrongaftershocksaboveML4.5complywithalinearrelationship,whichisconsistentwiththecharacteristicsofamainshock-aftershocksequence.Furthermore,wecalculatethesourceparametersandanalyzetheruptureprocessbasedontheempiricalrelationshipsfortheYutianearthquake,andtheresultsindicateafrictionalundershootbehaviorinthedynamicsourceprocessoftheYutianearthquake,whichisalsoinagreementwiththelowerandsimilarbvaluescomparedwiththe2008MS7.3Yutianearthquakeandthe2012MS6.2Yutianearthquake.
简介:Aseismicarrayoftwentyfourseismometers(Qiaojiaarray)operatedbytheInstituteofGeophysics,ChinaEarthquakeAdministrationwassituatedalongtheZemuhefaultandthenorthendofXiaojiangfault,whichisapartoftheeastboundaryoftheChuan-Dian(Sichuan-Yunnan)rhombuscrustalmass.TheQiaojiaarraystartedoperationattheendofFebruary,2012.SincethentheApril20,2013LushanMS7.0earthquakeandtheAugust3,2014LudianMS6.5earthquakehaveoccurredinthevicinityoftheQiaojiaarray.TheearthquakecataloguerecordedbytheQiaojiaarraysinceMarch,2012isusedinthisstudy.ThetemporalvariationoftheearthquakecountbeforetheLushaneventandtheLudianeventisanalyzed.Theresultsareasfollows:①AverycleargraduallyincreasingvariationofthecountofM≥2.0earthquakeswithintheregion,whereallearthquakesrecordedbytheQiaojiaarraycoveragecanbefoundbeforetheLushaneventandtheLudianevent,andtheincreasingrangeanddurationofthecountbeforetheLudianeventarebothlargerthanthosebeforetheLushanevent.②IntheregioncoveredbytheQiaojiaarray,forearthquakeswithdepthh≤10kmarisingprocessofthecountwasmanifestedbeforebothevents,alongwithanearlysamedurationofaboutfiveandahalfmonths,andforearthquakeswithdepthsh>10kmarising-droppingprocessofthecountwasmanifestbeforetheLushanevent,beforewhichtherising-droppingprocessappearedagain.Thevariationofthecountforearthquakeswithdepthh≤10kmisthereverseofthatforearthquakeswithdepthh>10km.③WithinandneartheregioncoveredbytheQiaojiaarray,thevariationofthecountmanifestsarisingprocessforearthquakeswithdepthh≤10kmorh>10kmbeforetheLushaneventandonlyforearthquakeswithdepthh≤10kmbeforetheLudianevent.Thevariationofthecountmanifestsaweakeningprocessforearthquakeswithdepthh>10kmbeforetheLushanevent.Itisshownfromtheaboveresultsthattheseismicitywit
简介:TheYutianearthquakewithM_S7.3happenedonFebruary12,2014.Theprecursormonitoringabilityisweakinthatarea.Wefoundtendencyanomaliesandmiddle-andshort-termanomaliesfrommetalpendulumtiltmeasurementsinHotanseismicstationbeforetheearthquake.AndwealsocomparedtheanomalieswiththatoftheM_S7.3YutianearthquakeonMarch21,2008.Thetendencyanomaliesmeasuredbythemetalpendulumtiltmeterappearedsince2012astiltingeastward.Whilethemiddle-andshort-termanomalieswerecharacterizedbyacceleration,pauseandrapidchangeoftiltrateintwodirections.Thetendencyanomaliesofmetalpendulumtiltrecordsarethesamebeforethetwoearthquakes.Theybothhappenedintheeastdirection.However,therearedifferencesinduration,characteristicandearthquakeintervalsforthemiddle-andshort-termanomalies.
简介:Wesuccessfullyemployanautomaticcentroidmomenttensor(CMT)inversionsystemtoinfertheCMTsolutionsoftheFebruary12,2014MS7.3Yutian,Xinjiangearthquakeusingnear-fieldseismicwaveforms(4°<△<12°)observedbythevirtualChinaseismicnetworks,whichhavebeenrecentlysetup.Theresultsindicatethatthiseventoccurredonaruptureplane(strike243°,dip70°,andrake-18°),showingleft-lateralstrike-slipfaultingwithaminornormal-faultingcomponent.Thecentroidinthehorizontaldirectionislocatednearly13kmeastoftheepicenter(36.123°N,82.499°E),andthebest-fittingcentroiddepthisaround10km.Thetotalscalarmoment,M0,isretrievedwithanaveragevalueof3.05×1019N·m,correspondingtomomentmagnitudeMW6.92.Mostoftheenergyisreleasedwithinabout14s.Moreover,wediscussaboutthepotentialapplicationofthissysteminearthquakedisasterdecision.
简介:ThepaperinvertsthefocalmechanismsolutionsoftheYutianM_S7.3mainshock,foreshocksandM_S≥3.5aftershocksbyusingtheCAPmethod,basedonthebroadbandwaveformsrecordedbytheXinjiangandTibetDigitalSeismicNetworks.TheresultsshowthattheM_S7.3strongearthquakeisofstrike-sliptypewithanormalfaultingcomponent,andcombinedwiththeanalysisoffocalstructureandtheaftershockdistribution,thenodalplaneIwithstrike241°,dip90°andrake-22°isconsideredtobetheseismogenicfaultplaneofthemainshock.ThedirectionofP-axisforthemainshockis194°,closetothenearNSdirectionoftheprincipalstressP-axisofhistoricalstrongearthquakesinthisregion.ThefocalmechanismsolutionoftheM_S5.4foreshockhasagoodconsistencywiththatofthemainshock.Amongthe18aftershocks,10areofstrike-sliptype,6areofnormalfaultingtypeand2areofthrusttype.70%oftheaftershocksinthesequencehaveafocalmechanismwithP-axisinthenear-NSdirection.ThefocaldepthsofthisM_S7.3earthquakesequencesaredistributedintherangeof5km-28km,withthemajorityinthedepthrangeof15km-20km,slightlydeeperthanthedepthof10kmofthemainshockascalculated.
简介:Thispaperintroducesthegeologicalstructurebackgroundaroundthe2014YutianM_S7.3earthquakearea,investigatesandanalyzestheregimeofsmallearthquakeactivityandthecharacteristicsofregionalseismicitypatterninXinjiangbeforetheearthquake,andcomparesthecharacteristicsoftheregionalseismicactivitywiththe2008YutianM_S7.3earthquake.Theresultsshow:12~3yearsbeforethe2014YutianM_S7.3earthquake,Xinjiangwasinaseismicactivestatewithstrongearthquakeoccurringsuccessively,andbeforethe2008M_S7.3earthquake,Xinjiangwasinthequietstateofmoderate-smallearthquakeswithM3.0~4.0.2BeforethisYutianM_S7.3earthquake,theregionalseismicactivityshowedashort-termanomalyfeature,thatis,seismicityofM≥5.0earthquakessignificantlyincreasedontheAltunseismiczoneandinthesourceareathreeyearsbeforetheM_S7.3earthquake,whileafiveyearlongquiescenceofseismicityofM≥4.0earthquakesappearedontheeastofthesourceareainarangeofabout440km.SixmonthsbeforethisM7.3earthquake,thereexistedseismicgapofM3.0~4.0earthquakesandnear-conjugateseismicbeltmagnitude3.0and4.0inthesourcearea.3ThestateofstrongearthquakeactivityandtheseismicitypatternofsmallearthquakesbeforethisYutianM_S7.3earthquakeweresignificantlydifferenttothatbeforethe2008YutianM_S7.3earthquake,andthismayberelatedtothedifferentseismogenicenvironmentsofthetwoM_S7.3earthquakes.
简介:2015年4月25日尼泊尔廓尔喀地区发生Ms8.1级地震,本文分析了加德满都强震台站的强地震动记录特征,其水平向地震动表现为明显的脉冲地震动,脉冲周期约为6.0s,反映了近场地震动的方向性效应;处于深厚沉积层上的加德满都谷地对地震动有一定的放大作用,且主震的场地峰值频率向低频段偏移,出现明显的场地非线性反应;采用随机有限断层方法模拟的空间地震动分布与宏观地震烈度图符合较好,可以为分析宏观震害提供参考;通过与尼泊尔设计反应谱对比,得出在短周期与长周期段,加德满都台站的水平向地震动的反应谱远高于设计反应谱,说明即使严格按照尼泊尔建筑抗震规范设计施工的建筑结构也难以抵御此次地震的破坏.
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.