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(MD)震源深度(Km)震中烈度 地震类型 199203030602228118°10′24°06′118°06′24°12′漳浦海外(厦门南)48Ⅴ孤立型 表1中宏观震中是根据陆地上勾划的等震线推测的,在微观震中的北西20公里左右。二、地震烈度分布本次地震的波及面很广,闽东南沿海地区均明显有感,调查在Ⅴ、Ⅳ度两个区内进行。由于地震影响场只有一小半在陆地上,勾勒出的是Ⅴ、Ⅳ度两条等震线的半椭圆弧线(见图14-1)。图14-1 1992年3月3日漳浦海外地震等震线图Ⅴ度区:震中位于海上
简介:Abrandnewexpertsystemforearthquakeprediction,calledESEP3.0,wassuccessfullydevelopedrecently,inwhichthefuzzytechnologyandneuralnetworkconceptionwereincorporatedandthesteeringinferencemechanismwasintroduced.Inadditiontothefunctionsofsymbolinferenceandexplanationofthefirstgenerationoftheexpertsystemandtheknowledgelearningofthesecondgeneration,ESEP3.0hasstrongerhuman-machineinteractionfunction.Itconsistsofknowledgeedition,machinelearning,steeringfuzzyinferenceengineandsynchronousexplanationsubsystems.Inthispaper,thecomponentsandthegeneraldescriptionofthesystemareintroduced.
简介:ThemainshockandaftershocksoftheHutubiMS6.2earthquakeonDecember8,2016wererelocatedbyapplyingthedoubledifferencemethod,andwerelocated477earthquakesintheHutubiregion.Theearthquakerelocationresultsshowthattheaftershocksaredistributedintheeast-westdirectiontowardsthenorthsideofthesouthernmarginoftheJunggarBasinfault,andaremainlydistributedinthewesternregionofthemainshock.ThedistancebetweenthemainshockafterrelocationandthesouthernmarginoftheJunggarBasinfaultisobviouslyshortened.Combinedwiththefocalmechanismandthespatialdistributionofthemainshockandaftershocks,itisinferredthatthesouthernmarginoftheJunggarBasinfaultisthemainseismogenicstructureoftheHutubiearthquake.
简介:ThetimeseriesofcoordinatesofalargenumberofGPSstationsintheworld,processedbyProf.GeoffreyBlewittwithGIPSYsoftwareareavailableathttp://geodesy.unr.edu.BasedonthetimeseriesofcoordinatesintheglobalreferenceframeofIGS08atmorethan250stationsofcontinuousGPSobservations,downloadedfromthewebsite,theco-seismicdisplacementsoftheM7.3KyushuearthquakeonApril16,2016inJapanandthepre-seismicstrainaccumulationsanddisplacementsintheregionalreferenceframewereobtained.ThestationofcontinuousGPSobservationatBJFSnearBeijinghasbeenquitestableindisplacementintheeasternpartofChinaformorethan17yearssincethebeginningofitsoperation,andthisstationisusedasthecorestationintheregionalreferenceframeforthepre-seismicdisplacementoftheKyushuearthquakeofM7.3.Themainfeatureofthepre-seismicdisplacementsoftheKyushuearthquakeischaracterizedbylockinginthecrustatandneartheepicenter.Theanomalouspre-seismicstrainaccumulationdevelopedinanareaofanomalousaccumulationoftheshearstraincomponentofγ1onthenortheastsideoftheepicenter,withincreasingsizeoftheareaandincreasingmagnitudeinγ1.Thelargestareacoveredbytheanomalousγ1isabout2000km2.ThechangeintheEcomponentatBJFSsinceNovember26,2015wascausedbythereplacementofthereceiverandtheantennaatthestation.Inordertostudytheshort-termchangeindisplacementsatstationsatandneartheepicenter,thetimeseriesat3stationswithcontinuousGPSobservations,2atSUWNandDAEJinsouthKoreaand1atBJSHnearBeijingwereanalyzed.Theanalysisshowsthatthedisplacementsatthe3stationshavebeenquitestableinthesamemannerineastAsia.Thus,BJSHisusedasthecorestationintheregionalreferenceframeofdisplacementandthedisplacementtimeseriesshowthattherewerenosignificantshorttermanomaliesbeforetheearthquake
简介:在2016年新西兰凯库拉Mw7.8地震中,北东一北东东向科科仁古断裂水平右旋位移量最大,为10-12m;北北西一近南北向帕帕提断裂垂直位移量最大,达到5—6m。对直接坐落在这2条地震地表破裂带或变形带之上的建筑物的破坏现场调查表明,尽管房屋出现歪斜,但上部主体部分基本完整,没有出现倒塌或部分倒塌现象,避免了人员伤亡。在无法回避活动断裂及其大震危险性的情况下,隔震系统的广泛采用可以有效地提高建筑物抵御地震灾害的能力。此次地震触发了数万个滑坡体,最大滑坡体可达数百万立方米。对沃罗村北边2处边坡失稳地带的考察结果表明,针对该地至少从2个方面进行了考虑和处置:一是在选址上,避开了突出山嘴等高陡坡地带;二是在房屋正对的山坡地带,种植或保护了茂密的树木,这既增加了山体的稳定性,又可以在地震中有效地减缓崩塌的石块对房屋的冲击。对比中国中东部一些大震,如1976年唐山7.8级地震和2008年汶川8.0级地震中触目惊心的巨大人员伤亡和财产损失,即使在人口密度与滑坡规模上存在明显不同,对新西兰凯库拉地震灾害现场的考察结果,还是在如何有效抵御地震灾害方面给我们提供了很好的启示。
简介:Theconventionalpseudo-staticapproachoftenneglectstheeffectoftheverticalseismicaccelerationonthestabilityofaslope,butsomeanalysesunderplane-strain(2D)conditionsshowasignificanteffectontheslopestability.Thepurposeofthisstudyistoinvestigatetheeffectoftheverticalaccelerationonthesafetyofthree-dimensional(3D)slopes.Inthestrictframeworkoflimitanalysis,a3Dkinematicallyadmissiblerotationalfailuremechanismisadoptedherefor3Dhomogeneousslopesinfrictional/cohesivesoils.Asetofstabilitychartsispresentedinawiderangeofparametersfor3Dslopesundercombinedhorizontalandverticalseismicloadingconditions.Accountingfortheeffectsoftheverticalseismicacceleration,thedifferenceinsafetyfactorsfor3Dslopescanexceed10%,whichwillsignificantlyoverestimatethesafetyofthe3Dslopes.
简介:TheQilianMountainactivesourcenetworkdatawasprocessedusingthemethodsofstacking,cross-correlationandinterpolation,andtheairguntraveltimevariationcharacteristicsofPandSwavesaroundtheJanuary21,2016MS6.4Menyua,Qinghaiearthquake.Theresultsshowthatabout6monthsbeforetheearthquake,therelativetraveltimeofthreestationsneartheepicentershowedadeclinedchange(traveltimedecrease),andsuchachangeoflowvalueanomalywasrecoveredabout3monthsbeforetheearthquake.Thetraveltimedecreasethenappearedagain,andtheearthquakeoccurredduringtherecoveryprocess.ThemaximumdecreaseoftheS-wavetraveltimewas18ms,andthechangeintraveltimereturnedtonormalaftertheearthquake.Thevariationtrendofthe3stationsisconsistent,includingtheS-wavetraveltimechangeofstationZDY38,whichisnearesttotheepicenterandchangedobviously,andthevariationrangeofthetraveltimeissmalleratthestationsafar.Thisvariationpatternisrelatedtothepositionoftheseismicsource.Theshortertraveltimemeansthevelocityincrease,whichmayberelatedtotheregionalstressaccumulation.
简介:TheseismicwaveformoftheYutianMS7.3earthquake,XinjiangonFebruary12,2014wasrecordedclearlyandcompletelybytheDigitalSeismicNetworksofXinjiang,Qinghai,Tibet,andXinjiangHotanarray,sothemethodofjointlocationbyregionalseismicnetworkandseismicarraycanbeusedtoaccuratelydeterminetheearthquakesourcelocation.Thefollowingtechnologieswereusedintheprocessoflocation:(1)WeselectedseismicstationsequallylocatedaroundtheepicenteroftheMS7.3earthquakewithanaverageintervalofabout15degreesintheinitiallocation.(2)TherecordingwaveformsofYutianseismicstationwererotatedtotheradialandtangentialdirectionstopreciselyobtainthearrivaltimeofS-wavestodeterminetheepicentraldistance.(3)Thevelocitymodelwasusedinthedeterminationoflocationoftheepicenter,basedonthehistoricalrecordsofearthquakesintheareawithinaradiusof1.0°fromthesourceasthecenter,andthevelocitymodelisobtainedafterre-fittingandcalibration.(4)BasedonthewaveformrecordsoftheHotanseismicarray,themethodofwaveformbeamingwasusedtodeterminetheazimuthsandperformthecorrectionoftheepicenterlocationwiththeseazimuths.(5)Thedeterministicmethodwasusedtomeasurethesourcedepth.Finally,itisconcludedthattheYutianMS7.3mainshockhypocenterlocationis36.197°N,82.467°E,focaldepth12kmandoriginaltime17:19:48.2p.m.February12,2014.
简介:ThispapercalculatesthestaticCoulombstresschangesgeneratedbyfourearthquakesintheYutianareaduring2008~2014separately,thendiscussesthetriggeringinfluence,theiraccumulatedCoulombstresschangesandtheirinfluenceonnearbyfaults.TheresultsindicatethattheMS5.5earthquakein2011andtheM_S7.3earthquakein2014arebothintheregionswheretheCoulombstresschangeispositive,thestresschangesare0.004MPaand0.021MPa,respectively,meaningtheyaretriggeredbypriorearthquakes.TheMS6.2earthquakein2012occurredintheplacewhereCoulombstresschangewasnegative,soitispostponedbythepriorearthquakes.TheimageofCoulombstresschangesoftheMS7.3earthquakein2014isinaccordwithaftershocks(ML≥3.0)distribution,butsomeregionsonthefaultwheretheCoulombstresschangeispositivehavefewaftershocks,andstrongaftershocksmayoccuratthesedistrictsinfuture.Inaddition,thispapercalculatestheCoulombstresschangeonnearbyfaults,andfindsthattheCoulombstresschangesofdifferentelementsintheGGCfaultareverydifferent,andmustreceivestrongtriggered-influence,thoughtheresultmaybeinfluencedbytheinputfinitefaultmodel,sothereisstillalargeearthquake-risk.TheGGN,PLC,PLWandLBWfaultswerealsotriggeredbythefourearthquakesoccurringbetween2008~2014.TheirmaximumCoulombstresschangesallexceed0.002MPa,sotheyalsohaveastrongearthquakehazard.
简介:Preliminaryresultof3DgravitationalforwardcalculationstudyinBohaiSeaGUANGXIALIU1)(刘光夏)WENJUNZHAO2)(赵文俊)WENJUREN1)(任文菊)XIU...
简介:Theexperimentalresultsof3-Dfractureundercompressionareintroducedinbriefandthetheoryofstresscriterionof3-Dfractureisstudied.Methodstoimitateinitialfracturesaredeveloped.Itispointedthatthereareimportantdefectsintheextremevalue(EV)methodeverproposedbyPalaniswamyandKnauss.ThemajordefectliesinthatonlytwoEulerangles(2EA)areconsidered,butanotheroneisneglected.IfthevariationofallthethreeEulerangles(3EA)areconsidered,onecangetbetterresultwhichisconsistentwiththeobservationoffaultingthatextendsoncurvedsurfacesbutnotonplanes.Themethodofevaluatingmaximalnormalstressdirectionvector(NSDV)isproposedandfurtherprovedtobeequivalenttothe3EAmethod.ItisprovedthattheNSDVmethodcanbefurtheroptimizedtothemethodofcompositionofthefirstprincipaldifferentialplane(CFPDP).TheresultsfromCFPDPmethodcanfitthecurvedsurfacesofinitialgrowthobservedintheexperimentsof3-Dfracture.TheCFPDPmethodcanalsobeusedtointerpretthe3-Dfracturesoftheslippingsectionbetweentheasperitiesintheburiedfaultplanethatismodeledasellipsecrack.Theresultsof3-Dfracturecanbeappliedtointerpretingtherelatedproblemsoffaultingincludingthemechanismofalotofshatterrockswithdifferentdimensions,thecauseofearthquakesoccurredattheedgeofplateunderlowshearstress,andthemechanismofanisotropycausedbytheextensivedilatancyanisotropy(EDA)cracks.
简介:TheJuly3,2015PishanM_S6.5earthquakeoccurredintheintersectionareaoftheTarimblockandWestKunlunblockwherethemoderate-strongearthquakeshavebecomeactiveinrecentyears.Thispaperhasstudiedtheseismicityparametersoftheearthquakesequencessuchastheb-valueinthePishanregionanditsvicinity.Inaddition,wealsorelocatedtheaftershocksofthePishanM_S6.5earthquakeusingtheseismicphasereportbythedouble-differencemethod.ThetemporalandspatialvariationcharacteristicsofthePishanearthquakesequenceintherupturezoneareanalyzed.Thestudyisofgreatsignificanceintheseismichazardassessmentinthisregion.
简介:BodywaveforminversionforthesourceprocesoftheFebruary3,1996Lijiang,YunnanearthquakeYANGXU1)(徐扬)MASAYUKIKIKUCHI2)(菊地正幸)YOU-JIN...
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:帕米尔高原位于地中海-喜马拉雅地震带上,晚新生代以来随着印度板块向欧亚板块持续不断地挤压汇聚,其构造运动是欧亚大陆最强烈的地区。高原腹地发育一系列近SN向正断层,包括近SN向的塔什库尔干正断层所处的帕米尔中部现代区域的构造应力场以EW向水平拉张为主。2016年11月25日发生的阿克陶Ms6.7级地震的发震构造为塔什库尔干断层分支的NWW向木吉盆地北缘断层,其具有右旋走滑兼正断性质。地震在震中附近产生同震地表形变带,全长约lkm,呈近SN--NNE向水平拉伸,发育近EW—NWW向的张裂缝,为地震破裂的产物,张裂缝的最大水平拉伸位移量和最大垂直位移量分别为46cm和16cm。地表破裂带中的NE和Nw向张剪裂缝只是连接贯通这些雁列的张裂缝,其水平相对位移量取决于张裂缝的水平拉伸量和张裂缝之间的几何关系。地表形变带表现的拉张性质与帕米尔高原腹地区域现代应力场最大主压应力为垂直向基本一致,可能与深部热物质上涌造成的上地壳拉伸有关。而地表形变带呈近SN向水平拉张,与区域近EW向拉张应力场之间存在显著差异,这可能是木吉盆地北缘右旋走滑正断层阶区局部应力场调整的结果。
简介:边界条件能显著地在强烈地震下面影响斜坡行为。为了为有限元素(FE)评估边界条件的重要性,一张饮料桌子的模拟在斜坡反应上试验,一验证三维(3D)非线性的FE模型被介绍,并且数字、试验性的结果被比较。为那个目的,基于公开源码的计算站台OpenSees,柔韧的图形的用户接口SlopeSAR被采用,它简化努力集中的预处理和processing以后阶段。网孔决定效果也被探讨。参量的研究被执行在在结束脸包含边界程度和边界条件的三种类型的FE模型上评估边界条件的影响。通常,在边界程度的变化生产不一致的斜坡变丑。为二张结束脸,修理y方向排水量不是适当的模仿饮料桌子实验,结束墙在僵硬、不平。另外,3D的长度的影响倾斜最高的脸和处于二之间的差别的一个重要角色在结束边界条件打的斜坡戏的宽度面对(修理y方向排水量并且修理(y,z)方向排水量)。总的来说,这研究加亮对在模拟和试验性的结果之间的比较的评价竟然与到期的考虑被执行到边界的效果,这调节。
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.