简介:Theauthorsstudiedtheseismicactivity,precursoryanomaliesandabnormalanimalbehaviorbeforetheApril14,2010MS7.1Yushuearthquake.AnalysisshowedthatanomalieswerenotrichbeforetheMS7.1Yushuearthquake,butprominentanomalieswereobserved,suchasthelongandmid-termtrendanomalycharacterizedbytheseismicquiescenceofMS6.0,MS5.0andMS4.0earthquakes,andtheanomaliesinprecursorobservationofsurfacewatertemperatureinYushuandDelinghaandelectromagneticmeasurementinPingan.Therewerealargenumberofanimalbehavioranomaliesappearingoneweekbeforetheearthquake.AnM4.7earthquakeoccurred130minutesbeforethemainshock.Inthispaper,westudiedthedynamicprocessoftheYushuearthquakepreparationusingtheearthquakefocalmechanismsolutionsontheBayanHarblockboundarysince1996.TheresultsshowthattheKalakunlunM7.1earthquakein1996,theManiM7.5earthquakeandtheYushuMS7.1earthquakehavethesamedynamicprocess.Longandmid-termtrendanomaliesmayberelatedtothedynamicsofevolutionofdifferentearthquakes.Thispaperalsodiscussestherecurrenceintervalofstrongearthquakes,foreshockidentificationandprecursorobservationoftheYushuMS7.1earthquake.
简介:Anew3Dvelocitymodelofthecrustanduppermantleinthesoutheastern(SE)marginoftheTibetanplateauwasobtainedbyjointinversionofbody-andsurface-wavedata.Forthebody-wavedata,weused7190eventsrecordedby102stationsintheSEmarginoftheTibetanplateau.Thesurface-wavedataconsistofRayleighwavephasevelocitydispersioncurvesobtainedfromambientnoisecross-correlationanalysisrecordedbyadensearrayintheSEmarginoftheTibetanplateau.ThejointinversionclearlyimprovesthevSmodelbecauseitisconstrainedbybothdatatypes.Theresultsshowthatataround10kmdepththerearetwolow-velocityanomaliesembeddedwithinthreehigh-velocitybodiesalongtheLongmenshanfaultsystem.Thesehigh-velocitybodiescorrespondwellwiththePrecambrianmassifs,andthetwolocatedtothenortheastof2013MS7.0Lushanearthquakeareassociatedwithhighfaultslipareasduringthe2008Wenchuanearthquake.Theaftershockgapbetween2013Lushanearthquakeand2008Wenchuanearthquakeisassociatedwithlow-velocityanomalies,whichalsoactsasabarrierzoneforrupturesoftwoearthquakes.Generallylargeearthquakes(M≥5)intheregionoccurringfrom2008to2015arelocatedaroundthehigh-velocityzones,indicatingthattheymayactasasperitiesfortheselargeearthquakes.Jointinversionresultsalsoclearlyshowthatthereexistlow-velocityorweakzonesinthemid-lowercrust,whicharenotevenlydistributedbeneaththeSEmarginofTibetanplateau.
简介:Basedonthefittingonpaleoearthquakedataofintra-plateregionsinthenorthernpartofChi-naandgivingastatisticalmodeloftimeinterdependence,thepotentialdamageearthquakesinadefinitefutureperiodandcharacteristicsofpresentshocksalongtheLingwufaulthavebeenanalyzedbyusingdangerousprobabilityfunctionandsomenewdataconcerned.Wehavein-ferredthatthefaulthasenteredaperiodthatearthquakeswillprobablyoccur.ThereexistsapotentialdangerthatastrongearthquakewithMs7.0-7.5willoccurin10-100a.
简介:丽江-小金河断裂斜切中国西南“川滇菱块”,走向北东,为一高角度斜滑断裂.与平面遥感影像相比,通过三维影像解译断错地貌有显著的优越性.印度P5卫星数据具备真正2.5m分辨率,在制图方面,像对生成DEM以及制图精度可达1∶25000.本文依据立体像对提取DEM的原理,利用ENVI软件DEMExtraction模块提耿出了丽江-小金河断裂带P5立体像对的DEM.文中利用等高线套合分析法和剖面线法对DEM精度进行评价,结论认为,DEM精度优于1∶5万地形图等高线高程精度,而且与实时动态差分(RTK)测量结果比较一致.文章重点选取了丽江市北东方向干塘子和西南方向南溪盆地两处,将三种高程数据——从P5立体像对提取出的DEM、googleearth影像地形高程和1∶5万矢量地形图等高线生成的DEM,结合GoogleEarth影像做成三维立体影像,较为直观地对三种高程数据进行了有效的对比,结论认为,P5立体像对生成的DEM精度最高.在室内利用高精度三维立体图对丽江-小金河断裂断层地貌进行了解译,经过野外踏勘和探槽验证,证明三维影像解译具有很高的利用价值.
简介:论述1∶1000数字化地形测量产品作业方法与主要技术。
简介:正Thethesisofthepaper,whichistheobjectofthisDiscussion,isthattheconsiderabledamagesufferedbytheBasilica,aftertheearthquakeofL'Aquilain2009,wastheexclusiveresultoftheinterventionofseismicimprovementofthenaves,madein2000;such