简介：Ｓｐａｔｉａｌａｎｄｔｅｍｐｏｒａｌｖａｒｉａｔｉｏｎｏｆ　ｇｒａｖｉｔｙ　ｆｉｅｌｄｉｎｔｈｅｃａｐｉｔａｌｒｅｇｉｏｎＣｈａｎｇ－ＣａｉＨＵＡ；（华昌才）ＹｏｎｇＧＵＯ；（果勇）Ｄｕａｎ－ＦａＬＩＵ；（刘瑞法）ＧａｎｇＸＩＡＯ；（肖钢），Ｊ．Ｔ．...

简介：一个提起的实验连续地被进行三天，并且速度变化被测量用结尾，波浪interferometry.The测量错误被估计在10-4附近，它在这个时期期间与理论error.The速度变化与一致很好在空气温度直到在速度变化和变化之间的10-3.The关系，气压的压力和稳固的地球潮与线性最不方形的fitting.The被分析速度没在空气温度，而是displa上有依赖

简介：Focusingontheb-valueastheresearchtargetandunderthetheoreticalframeworkthattheb-valueisdeterminedbystressstateandmediumproperties,thevariationcharacteristicsoftheb-valueintheHetaoseismicbeltareanalyzed.EarthquakeswithML≥1.5,whichhaveoccurredintheHetaoseismicbeltsince1970areselectedtoconductthequantitativedetectionofthenon-uniformtemporalchangeofMcusingtheEMRmethod.Basedontheactualsituationofseismicactivity,thelowerlimitmagnitudeissetasML2.0tocalculatetheb-value.Thetemporalvariationoftheb-valueiscalculatedandscannedusingtheleastsquaremethod.Theresultsshowthatthereisagoodcorrespondingrelationshipbetweenthetemporalvariationoftheb-value,strongearthquakeactivity,networkdistributionandaftershockdeletion.Wealsocalculateandscanthespatialvariationoftheb-valuebyusingmaximumlikelihood.Theresultsshowthatthespatialdifferenceispossiblycausedbystressstateandcrustalmediumproperties.Thetectonicdependenceoftheb-valueisobvious.Inaddition,thesufficientearthquakessamplesineachmagnitudeintervalarestillakeysteptoimprovethecalculationaccuracyoftheb-valuevaluebyusingmaximumlikelihood.Theresultsshowthatthespatialdifferenceispossiblycausedbystressstateandcrustalmediumproperties.Thetectonicdependenceoftheb-valueisobvious.Inaddition,thesufficientearthquakessamplesineachmagnitudeintervalarestillakeysteptoimprovethecalculationaccuracyoftheb-value

简介：Inthisstudy,weadoptanimprovedBayesianapproachbasedonfree-knotB-splinebasestostudythespatialandtemporaldistributionoftheb-value.SynthetictestsshowthattheimprovedBayesianapproachhasasuperiorperformancecomparedtotheBayesianapproachaswellasthewidelyusedmaximumlikelihoodestimation(MLE)methodinfittingtherealvariationofb-values.WethenapplytheimprovedBayesianapproachtoNorthChinaandfindthattheb-valuehasaclearrelevancetoseismicity.Temporalchangesofb-valuesarealsoinvestigatedintwospecificareasofNorthChina.Weinterpretsharpdecreasesintheb-valuesasusefulmessagesinearthquakehazardanalysis.

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简介：IntroductionShort-to-imminentprecursorsstillarethemainbasisforearthquakepredictioninthepresenttime.Strongquakes,especiallythosewithnoforeshocks,canbeforecastedtosomeextentbasedonabundantshoat-to-imminentprecursorsandcombiningwiththemid-to-longtermvar...

简介：PnarrivaltimedataarecollectedfromthebulletinsofbothnationalandregionalseismologicalnetworkinChina.ThesedataaretomographicallyinvertedtomapthelateralvariationandanisotropyofPnvelocityinthenortheasternmarginalregionofQinghai-Xizangplateau.TheaveragePnvelocityinthisregionis8.09km/s,beingalittlehigherthantheaverageforwholeChina.HighervelocityisfoundintectonicallystableQaidambasin,whilelowervelocityisseeninandaroundtectonicallyactiveShanxigraben.Theregionwherethe1920HaiyuangreatearthquakeoccurredshowsaslightlylowPnvelocity.Anoticeableresultisthat,differingfromthetectonicallycompressiveTianshanregion,wherePnvelocityislow,theQilianshanregion,wheretheNeotectonicdeformationisalsoprimarilycompressive,showshighPnvelocity.IntheuppermostmantlebeneaththeOrdosplateauPnvelocityisinhomogeneous,varyingfromhighervelocityinsouthwesternparttoloweroneinnortheasternpart.ThismaybeattributedtopossiblemovementoftheOrdosblock,astherearestrongearthquakesallaroundtheblock.

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简介：Gravityvariationdataobservedintheprocessofseismogenesisandoccurrencesofearthquakesshowthatthelocationwiththegreatestgravitychangesdoesnotnecessarilycoincidewiththeepicenter.Toexplainthiswedefinedthecenterofeffectivemassofstressvolumeas"hypocentroid",andtheverticalprojectionofwhichontheearth'ssurfaceas"epicentroid".Hereweadoptthreerotatingmodels,includingspheroid,ellipsoidandcylinder,torepresenttheregionofanimpendingearthquake.Basedonthemodelsofgravityvariationsinducedbyuniformdilatancy,epicentroidsassociatedwithsixteenearthquakeswithM>4.0occurredin1981～2000intheBeijing-Tianjin-Tangshan-Zhangjiakouregionaredeterminedbymeansofaproposedleastsquaresiterativeinversionmethod.Theresultsindicatethatcylindermodelispreferabletotheothertwo,andepicentroidsobtainedbythecylindermodelseparatefromtheepicentersbyarangeof0～40km.Epicentroidsareinevitablylocatedwithinintacttectonicblocks,andusuallyclusteringroups;whiletheepicentersaregenerallylocatedattheterminationsoffaultsorattheintersectionsoffaults.Itseemsthatthereexistearthquake-hatchingareasintheblockamongfaults.Earthquakeshatchintheseareas,butoccuraroundtheseareas,meanwhiletheexistenceoffaultsmayplayanimportantroleincontrollingtheprocesses.

简介：Ingeneral,earthquakecyclerelatedtoearthquakefaultingcouldincludefourmajorprocesseswhichcouldbedescribedby(1)faultlocking,(2)self-accelerationornucleation(possibleforeshocks),(3)coseismicslip,and(4)post-stressrelaxationandafterslip.Asuddenstaticstresschange/perturbationinthesurroundingcrustcanadvance/delaythefaultinstabilityorfailuretimeandmodifyearthquakerates.Basedonasimpleone-dimensionalspring-sliderblockmodelwiththecombinationofrate-and-statedependentfrictionrelation,inthisstudy,wehaveapproximatelyderivedthesimpleanalyticalsolutionsofclockadvance/delayoffaultfailurescausedbyasuddenstaticCoulombstresschangeappliedinthedifferenttemporalevolutionperiodsduringanearthquakefaulting.Theresultshavebeenusedinthephysics-basedexplanationofdelayedcharacteristicearthquakeinParkfieldregion,California,inwhichthenextcharacteristicearthquakeofM6.0after1966occurredin2004insteadofaround1988accordingtoitscharacteristicreturnperiodof22years.Atthesametime,theanalyticalsolutionsalsoindicatethatthetimeadvance/delayinCoulombstresschangederivedbythedislocationmodelhasacertainlimitationandfundamentalflaw.Furthermore,wediscussedtheessentialdifferencebetweenrate-andstate-variableconstitutive(R–S)modelandCoulombstressmodelusedcommonlyincurrentearthquaketriggeringstudy,anddemonstratedthat,infact,theCoulombstressmodelcouldbeinvolvedintheR–Smodel.Theresults,wehaveobtainedinthisstudy,couldbeusedinthedevelopmentoftime-dependentfaultinteractionmodelandtheprobabilitycalculationrelatedtothetime-dependentandrenewalearthquakepredictionmodel.

简介：BasedonarrivaltimedataofseismicphasesofML≥2.0earthquakesmeasuredatShanxiDigitalSeismicNetworkfortheperiodfromJanuary2001toOctober2014,V_P/V_SintheShanxiregioniscalculatedusingtheWadatisinglestationandmulti-earthquakemethod,andaninvestigationisconductedintothevariationbehaviorofV_P/V_SintheShanxiregionbeforeandafterthethreeearthquakesofMS≥4.5in2010.OurstudyfindsthatabnormalV_P/V_Sappearedearlieratdistantstationsbeforeallofthethreeearthquakes,whichisatthetimerangefrom6monthsto1yearbeforetheearthquakes,andlateratnearstations,atthetimerange10daysto2monthsbeforeearthquakes.Therefore,itspossibletonarrowdownthescopeofthelocationinearthquakepredictionfromthedistantandnearstationdata.ThecalculationsofDongshanseismicstationindicatethatthesizeoftheresidualoftheorigintimehasimpactonthedetailofV_P/V_Svariation,thus,appropriatethresholdsshouldfirstlybesetfortheresidualsoforigintimeateachseismicstationinpracticalapplication,toensurescientificandsteadyV_P/V_Scalculations.

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简介：Thenon-tidalvariationgainedfromcontinuousgravityobservationsinstationsusuallyreflectstheregionalcontinuousgravitychanges.Inthispaperwefocusonstudyingthenon-tidalvariationofBaijiatuanstation,Beijingwheretherearetwodifferentgravimeters(namely,L&R-804andPET-031).Basedontheoriginalrawtidalrecordsoftwogravimetersfrom2008to2011,wefirstremovevariousinterferencefromrawdatabythestandardproceduresoftware-Tsoft;thenwemodelthesolidearthtides,oceantidalloadingandpoletidethroughrelatedparameters;afterthatweadoptanewsegmentedpolynomialfittingmethodbasedonTsofttofitthecomplexdriftofspringgravimeter;andfinallywecalculatetheatmosphericloadingeffectsbyalinearregressionmodel.Afteraseriesofprocessingwegainthenon-tidalvariationofthetwogravimetersatBaijiatuansite,Beijing.Furthermore,toanalyzethenon-tidalvariationpreliminarily,westudythemaincomponentofrelatedtidaldatabypowerspectraldensity.Comparingthenon-tidalvariationoftwodifferentgravimeters,wefindseasonalfluctuationsinnon-tidalresults,whichareinaccordancewiththewaterstoragechange.Therefore,wetakeintoaccounttherelevanceofgravitychangesandwaterstoragebasedonthegravitydataofGRACEandwaterdataoftheCMAPmodelfrom2003to2011atdifferentsitesintheChinesemainland(Beijing,Chengdu,ShenyangandShiquanhe),andmakeapreliminaryanalysisontherelationshipbetweengravitychangesandwaterstorage.

简介：SignificantanomalieswereobservedatthegeomagneticstationsinthesouthwestregionofChinabeforetheYingjiangMS6.1earthquakeandtheLudianMS6.5earthquakein2014.Weprocessedthegeomagneticverticalcomponentdiurnalvariationdatabythespatialcorrelationmethod.TheresultsshowthatduringtheperiodfromApril1toMay20,2014,thereexistedquasi-synchronousdecreasechangesinthecoefficientcurvesbetweenthefivegeomagneticstationsofGuiyang,Hechi,Nanshan,Muli,YongningandXinyiandHongshanstations.Furthermore,therewasahighgradientzoneinthenormalizedcorrelationcoefficientcontourmapwithbackgroundvaluesremoved.TheepicentersoftheYingjiangMS6.1earthquakeandtheLudianMS6.5earthquakearelocatedinthegradientzoneornearthegradientzone.

简介：ＴｉｍｅｓｐａｃｅｅｖｏｌｕｔｉｏｎｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆａｂｒｕｐｔｖａｒｉａｔｉｏｎｏｆｗａｖｅｖｅｌｏｃｉｔｙｒａｔｉｏｉｎｔｈｅｓｅｉｓｍｏｇｅｎｉｃｐｒｏｃｅｓｏｆｒｅｃｅｎｔｓｔｒｏｎｇｅａｒｔｈｑｕａｋｅｓｉｎＹｕｎｎａ...

简介：在到地震预言的MODIS卫星遥感数据的应用程序的学习，论文第一次提出一个量的方法与反常亮度温度(BT)为象素估计比率为云移动的增加和一个初步的计划。原则是第一，无云的数据在时间，但是在不同的天内的一样的时期由一样的卫星观察了(通常1天到3天)是mosaiced得到晴朗天空的高比率，然后BT变化曲线和每个象素的mcan平方差别(MSD)从盖住的区域与数据被计算每天决定今日的BT数据作为标准用两倍MSD在某个象素由是正常的。为有反常BT增加的象素的比率能被与整个区域的全部的象素划分反常象素的全部的数字计算。在台湾区域的一系列最近的地震上的分析证明为有反常BT增加的象素的比率，通常在零附近波动，有突然的改进1天到在媒介强壮的地震前的20天。为识别地震预兆的一个新方法能被从MODIS卫星遥感随反常BT增加为象素分析比率的变化与经常的地震活动在区域通过特殊研究发现，这被期望红外线(红外)云的效果从被移开的信息到某个程度。