简介：AnM_S7.3earthquakeoccurredonFebruary12,2014inYutianCounty,XinjiangUygurAutonomousRegion,whichwasfollowedbyaseriesofaftershocks.ThispapercalculatesthedepthoftheM_S7.3earthquakesequencebyusingthedeterministicapproachwiththeseismicphasedatafromthecatalogdatabaseoftheChinaEarthquakeNetworksCenter,combinedwithoriginalseismicwaverecordsfromtheDigitalSeismicNetworkCenteroftheEarthquakeAdministrationofXinjiangUygurAutonomousRegion.

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：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：2014年8月3日发生的鲁甸地震是我国继2013年芦山地震之后的又一次破坏性浅源地震,造成了严重的人员伤亡和工程结构破坏.本文处理了我国数字强震动台网捕获的60余组主震三分量强震动记录,绘制了震中附近区域的峰值加速度等值线图,长轴沿西北-东南方向展布.通过与中国西部常用衰减关系的对比,发现各模型的预测值均不同程度高估了峰值加速度、峰值速度的观测值.最后以水平向峰值加速度较大的三个典型台站为例,详细调查了附近建筑的破坏情况,结合宏观烈度分布结果,分析了地震动特征与震害的相关性.

简介：Thedensebroadbandseismicnetworkprovidesmorehigh-qualitywaveformthatishelpfultoimproveconstraintfocaldepthofshallowearthquake.Manyshallowearthquakesoccurringinsedimentwereregardedasinducedevents.InSichuanbasin,gasindustryandsaltminingaredependentonfluidinjectiontechniquethattriggersmicroseismicity.WeadoptedwaveforminversionmethodwithregionalrecordstoobtainfocalmechanismofanMs4.8earthquakeatChangning.TheresultsuggestedthattheChangningearthquakeoccurredataESEthrustfault,anditsfocaldepthwasabout3km.ThedepthphasesincludingteleseismicpPphaseandregionalsPLphaseshowsthatthefocaldepthisabout2km.Thestrong,shortperiodsurfacewavesuggeststhatthiseventisaveryshallowearthquake.TheamplituderatiobetweenRayleighwaveanddirectSwavewasalsousedtoestimatethesourcedepthofthemainshock.Thefocaldepth(2–4km)isfarlessthanthedepthofthesedimentarylayerthickness(6–8km)inepicentralregion.Itisclosetothedepthoffluidinjectionofsaltmining,whichmayimplythatthiseventwastriggeredbytheindustrialactivity.

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：本文采用朱介寿等（1984）提供的非均匀速度模型,使用Hypo2000地震定位方法,筛选出汶川MS8.0级地震前8年的2723条地震记录进行精定位;震源深度的优势分布介于5-20km之间,平均震源深度是12km.结合地震震中分布图、震源深度剖面图、M-T图等结果,得出汶川MS8.0级地震前龙门山断裂带北段地震活动性比中段和南段的活动性弱;时间越临近2008年5月12日汶川8.0级地震发生前,周边的应力场逐步增强,靠近汶川主震区域的震群活动有增加的迹象.

简介：通过对武都应变台多年应变资料的处理分析后发现,在汶川8.0级地震发生前,武都台应变有显著的前兆异常变化,它与昆仑山口西8.1级地震前出现的异常有很高的相似度.昆仑山口西地震和汶川地震前都有“α-β-γ”形变阶段,在不同的前兆异常阶段,异常形态有明显的差异,而且各具特点.尤其在β1阶段,EW道、面应变、差应变的异常变化（中期异常）都出现在震前2-3年,持续时间约1年多,而且异常都非常显著.本文详细分析了武都台应变在各个阶段的前兆异常变化特征,并就其原因进行了初步分析.

简介：Inviewofthecorrelationbetweentectonicactivityandseismicity,thestrongearthquakeriskintheNorth-SouthSeismicBeltarousedwideconcernafterthe2014YutianM_S7.3earthquake.UsingtheseismiccatalogoftheChinaEarthquakeNetworksCenter,theBenioffstrainratiointheNorth-SouthSeismicBeltiscalculatedin30daysbeforeandaftertheMarch21,2008andFebruary12,2014YutianM_S7.3earthquakes.Resultsshowthatinayearafterthe2008YutianM_S7.3earthquake,M>5.0earthquakesalloccurrednearthehighstrainratioareaorthejunctionbetweenthelowandhighstrainratioareas,theactivityofstrongearthquakesobviouslycoincideswiththehighstrainratioarea,whichindicatesthattheseareashaveahigherstresslevel.TheYutianearthquakespromotedthereleaseofsmallearthquakesinthehighstressareas.Thisresearchisofcertainindicatingsignificancetothestudyofsubsequentstrongearthquakesofthisregion.