简介：ThispapersummarizesthebasicsituationoftheBinchuanTransmittingSeismicStationandthegeophysicalobservationsoftheareawhereitislocated,withafocusontheconstitutionoftheobservationsystemofthetransmittingseismicstation,theexcitationcharacteristicsandpropagationdistanceofsignalsexcitedbytheairgunsourceinthereservoirandwell.ThepaperalsosummarizesanddiscussesontheresultsoftheobservationsandproblemsencounteredsincetheTransmittingSeismicStationwasbuilt.Finally,thispaperproposesthemainresearchtobecarriedoutonthebasisoftheprojectaims.

简介：Onthebasisoftheviewpointofpreparationofstrongearthquakesingroup,thespatialandtemporalscanningcharacteristicsoftheseismicityintheSouthYellowSeaanditscoastregionarestudied,andsomeproblemsregardingthepredictionofseismichazardarealsodiscussed.TheresultsshowthattheseismicactivityofM=4.0earthquakeshasoverallpresentedarelativestablestate,butthepartiallyconcentratedareawbichevolvesandmigratesandtheanomalouslowb-valueareahaveappearedindifferentperiods,andthemoderatelystrongearthquakeswithM=5.0～6.0havetakenplaceontheedgeoftheanomalousarea.TheaccumulativefrequencyofM=4.0earthquakesintheanomalousareapresentsnon-linearindexaccelerationandthemoderatelystrongearthquakeshaveappearedinthelateperiodofthenon-linearindexaccelerationofM=4.0earthquakesorinthelateranomaloustranquilperiotl.ThespatialandtemporalunevenPhenomenonofseismicityhassomestabilityandreproducibility,andhassom

简介：Heatflowisinevitablyaccompaniedbytemperaturechange,thus,thewatertemperaturecoseismicresponseduringearthquakeactivityshouldalsoobeythelawsofthermodynamics.TakingtheMS8.0Wenchuan,Sichuan,ChinaearthquakeandtheM9.0Tohoku,Japanearthquakeasanexample,andbasedonthedataofwatertemperaturecoseismicresponsesobservedinwellZK26inHaikou,HainanProvince,China,weinvestigatetherelationshipbetweenwellwatertemperaturechangeandheattransferinthecoseismicresponseprocessandtherelevantthermodynamicmechanismbyusingthenumericalsimulationmethodforthermodynamicequations.Then,throughforwardmodeling,weobtainseveralsimulationcurvesofwatertemperaturechangeinresponsetoearthquakesalongthewelldepthatdifferenttimes.Thesimulatedcurvesofwatertemperaturechangeapproximatelyfittheobservedcurves.Consequently,basedonthevariationoftemperature,wefindthatthemodesofwellwatertemperaturecoseismicresponse(ascending,descendingorstable)arerelatedtofactorssuchasthelocationofsensors,distributionandlocationofheatsources,thespanbetweensensorsandheatsources.

简介：Thisarticlemadeasystematicstatisticalanalysisontheduration,spatialdistribution,form,range,typeandreliabilityofprecursoryanomaliesbasedontheobservationsofprecursorsof24moderate-strongearthquakesoccurringalongtheTancheng-LujiangfaultzoneanditsbilateralareasinShandong,Liaoning,Hebei,JiangsuandJiangxiProvincesintheperiodfrom1966to2005.Resultsshowthat:(1)ForM7.0andM6.0earthquakes,med-termabnormitiesarethegreatestinnumber,short-termabnormitiescomesecond,andimminentanomaliesaretheleast.ForM5.0earthquakes,short-termabnormitiesareoftenthemostinnumber,imminentanomaliescomesecond,andthemed-termonesaretheleast.(2)Precursoryanomaliesareperiodical,partofthemedandshort-termanomaliesareshownasshort-termandimminentanomaliesduringtheirdevelopment.(3)Thedevelopmentofprecursorshowsquasi-synchronism;theclosertoearthquakeoccurrencetime,themoreturningchangesofanomalieswillappear.(4)Anomaliesmainlyoccurwithinanepicenterdistanceof100km,showingarelativeconcentrateddistributioninspace,andtheshorterthedistancetoepicenter,thehighertheanomalystation/itemrate.(5)Thespatialdistributionofanomaliesisrelativelycorrelatedtothestrikeofstructures,havingagoodconsistencywiththestructure.(6)Thereisnosignificantcorrelationbetweendurationofabnormitiesandtheepicenterdistance.(7)Thehigherthemagnitudeoftheearthquake,thegreatertheamplitudeoftheabnormitiesmeasuredwiththesameobservationapproach.(8)Intermsoftheitemsoftheobservations,fluidabnormitiesarethegreatestinnumber,followedbydeformationandelectromagnetismobservations.(9)Forallobservationitems,medandshort-termabnormitiesmakeupthemajorityandshort-termandimminentanomaliestheminority.(10)Influid,deformationandelectromagnetismobservations,fairlyreliableanomaliesareaboutdoublethenumberofreliableanomalies.

简介：Withtheimprovementofseismicobservationsystem,moreandmoreobservationsindicatethatearthquakesmaycauseseismicvelocitychange.However,theamplitudeandspatialdistributionofthevelocityvariationremainsacontroversialissue.RecentactivesourcemonitoringcarriedoutadjacenttoWenchuanFaultScientificDrilling(WFSD)revealedunambiguouscoseismicvelocitychangeassociatedwithalocalMs5.5earthquake.Here,wecarryoutforwardmodelingusingtwo-dimensionalspectralelementmethodtofurtherinvestigatetheamplitudeandspatialdistributionofobservedvelocitychange.ThemodeliswellconstrainedbyresultsfromseismicreflectionandWFSDcoring.Ourmodelstronglysuggeststhattheobservedcoseismicvelocitychangeislocalizedwithinthefaultzonewithwidthof*120mratherthandynamicstronggroundshaking.Andavelocitydecreaseof*2.0%withinthefaultzoneisrequiredtofittheobservedtraveltimedelaydistribution,whichcoincideswithrockmechanicalexperimentandtheoreticalmodeling.

简介：

简介：Two-monthcontinuouswaveformsof108broadbandseismicstationsinFujianProvinceanditsadjacentareasareusedtocomputenoisecross-correlationfunction(NCF).ThesignalqualityofNCFisimprovedviatheapplicationoftime-frequencyphaseweightedstacking.TheRayleighandLovewavesgroupvelocitiesbetween1s-20saremeasuredonthesymmetricalcomponentoftheNCFwiththemultiplefiltermethod.Morethan5,000Rayleighwavedispersioncurvesandabout4,000Lovewavedispersioncurvesareobtainedandusedtoinvertforgroupvelocitymaps.Thisdatasetprovidesabout50kmresolutionthatisdemonstratedwithcheckerboardtests.Consideringtheoffgreatcircleeffectininhomogeneousmedium,theraypathistracedbasedonthetraveltimefieldcomputedwithafinitedifferencemethod.Theinvertedgroupvelocitymapsshowgoodcorrelationwiththegeologicalfeaturesintheupperandmiddlecrust.TheFuzhoubasinandZhangzhoubasinshowedlowvelocityontheshortperiodgroupvelocitymaps.Onthelongperiodgroupvelocitymaps,thelowvelocityanomalyinthehighheatflowregionnearZhangzhouandclearvelocitycontrastacrosstheZhenghe-Dapufaults,whichsuggeststhattheZhenghe-Dapufaultmightbeadeepfault.

简介：根据历史的地震记录的详细学习和在1573A.D的MinxianM61/2地震的原因的结构，我们发现了最严重的灾区附近躺Minxian县位子(在那时间的Minzhou县)。那么，我们识别了1573A.D的极其地震的区域MinxianM61/2地震位于Minxian城市，meizoseismal区域的紧张是，震中是34.4???δ

简介：ｔｕｄｙｏｎｃｒｕｓｔｍａｎｔｌｅｔｅｃｔｏｎｉｃｓａｎｄｉｔｓｖｅｌｏｃｉｔｙｓｔｒｕｃｔｕｒｅａｌｏｎｇｔｈｅＢｅｉｊｉｎｇＨｕａｉｌａｉＦｅｎｇｚｈｅｎｐｒｏｆｉｌｅＺＨＩＰＩＮＧＺＨＵ（祝治平）ＸＩＡＮＫＡＮＧＺＨＡＮＧ（张先康）...

简介：TheLateCenozoicstratigraphicsequenceanditsinformationoftectonicevolutionareobtainedherethroughthedetailedpetrostratigraphicandmagnetostratigraphicstudyandresearchofstratigraphiccontactandsedmentaryfacesoftheCenozoicstrataprofile,Hejiakouziarea,NingxiaHuiAutonomousRegion.TheintenseCenozoictectonicdeformationbeganat10MaBPintheHaiyuan-TongxinSyntaxis,thenortheasternmarginofQinghai-XizangPlateau,andafewdeformationeventsoccurredduringLateCenozoicEra.

简介：UsingpureSwavefittingmethod,westudiedtheshearwavevelocitystructuresundertheOrdosblockanditseasternandsouthernmarginalareas.TheresultsshowthatthevelocitystructurebeneathYulinstationintheinteriorofOrdosblockisrelativelystable,wherenoapparentchangebetweenhighandlowvelocitylayersexistsandtheshearwavevelocityincreasessteadilywiththedepth.Thereisa12kmthicklayeratthedepthof25kmunderthisstation,withanSwavevelocity(Vs=3.90km/s)lowerthanthatatthesamedepthinitseasternandsouthernareas(Vs≥4.00km/s).ThecrustundertheeasternmarginofOrdosblockisthickerthanthatoftheYulinstation,andthevelocitystructuresalternatebetweenthehighandIowvelocitylayers,withmorelowvelocitylayers.Ithasthesamecharacteristicashavinga10km-thicklowvelocitylayer(Vs=3.80km/s)inthelowercrustbutburiedatadepthofabout35km.Moreover,westudiedtheVi/VsratioundereachstationincombinationwiththeresultofPwavevelocityinversion.Theresultsshowthat,theaveragevelocityratiooftheYulinstationattheinteriorofOrdosblockisonly1.68,withaverylowratio(about1.60)intheuppercrustandastableratioofabout1.73inthemidandlowercrust,whichindicatesthemediaunderthisstationishomogenousandstable,beinginastateofrigidity.ButatthestationsintheeasternandsouthernmarginsoftheOrdosblock,severallayersofhighvelocityratio(about1.80)havebeenfound,inwhichtheaveragevelocityratiounderKelanandLishistationsattheeasternmarginissystemicallyhigherthanthatofthegeneralelasticalbodywaves(1.732).Thisreflectsthatthecrustunderthemarginalareasismoreactiverelatively,andothermaterialsmayexistintheselayers.Finally,wediscussedtherelationshipamongearthquakes,velocitystructuresbeneathstationsandfaults.

简介：ＩｎｔｅｒｐｒｅｔａｔｉｏｎｏｆＳｗａｖｅｄａｔａｆｒｏｍＴａｉ′ａｎＸｉｎｚｈｏｕＤＳＳｐｒｏｆｉｌｅａｎｄｉｔｓｒｅｌａｔｉｏｎｓｈｉｐｗｉｔｈＸｉｎｇｔａｉｅａｒｔｈｑｕａｋｅｓＳＯＮＧＹＡＮＳＯＮＧ（宋松岩）１）ＸＵＥＳＯＮＧＺＨＯ...

简介：ResearchonthelargescalespatialheterogeneityofgreatintraplateshallowearthquakesontheChinesemainlandandadjacentareasdiscussedinthispapershowsthat(1)therearefourmainhighseismicityareas:theNorthChinaseismicareaintheeasternpartofChina(30°-42°N),theSoutheasternCoastseismicareaintheeasternpartofChina(19°-25°N),theNorth-SouthseismicareainthewesternpartofChinaanditsadjacentareas(Burma-China-Mongolia),andtheCentralAsianseismicareainthewesternpartofChinaanditsadjacentareas(Pamir-TianshanMountains-Baikal);(2)thefourintraplateseismicareasthatareapproximatelyperpendiculartothosesectionsoftheEurasiaplateboundarythatsurroundstheChinesemainlandanditsadjacentareas,wheretheEurasiaplatehasastrongseismiccouplingwiththeNorthAmerica-PacificOcean-PhilippineSeaplateandtheIndiaplate;and(3)thelargescalespatialheterogeneityofintraplateseismicityinChinaanditsadjacentareasthatmightbecontrol

简介：ThevelocitystructureofthecrustbeneathLiaoningprovinceandtheBohaiseainChinawasimagedusingambientseismicnoiserecordedby73regionalbroadbandstations.Allavailablethree-componenttimeseriesfromthe12-monthspanbetweenJanuaryandDecember2013werecross-correlatedtoyieldempiricalGreen'sfunctionsforRayleighandLovewaves.PhasevelocitydispersioncurvesfortheRayleighwavesandtheLovewavesweremeasuredbyapplyingthefrequencytimeanalysismethod.DispersionmeasurementsoftheRayleighwaveandtheLovewavewerethenutilizedtoconstruct2Dphase-velocitymapsfortheRayleighwaveat8–35speriodsandtheLovewaveat9–32speriods,respectively.BothRayleighandLovephase-velocitymapsshowsignificantlateralvariationsthatarecorrelatedwellwithknowngeologicalfeaturesandtectonicsunitsinthestudyregion.Next,phasedispersioncurvesoftheRayleighwaveandtheLovewaveextractedfromeachcellofthe2DRayleighwaveandLovewavephase-velocitymaps,respectively,wereinvertedsimultaneouslytodeterminethe3Dshearwavevelocitystructures.ThehorizontalshearwavevelocityimagesclearlyandintuitivelyexhibitthattheearthquakeswarmsintheHaichengregionandtheTangshanregionaremainlyclusteredinthetransitionzonebetweenthelow-andhigh-velocityzonesintheuppercrust,coincidingwithfaultzones,andtheirdistributionisverycloselyassociatedwiththesefaults.Theverticalshearwavevelocityimagerevealsthatthelowercrustdownwardtotheuppermostmantleisfeaturedbydistinctlyhighvelocities,withevenahigh-velocitythinnerlayerexistingatthebottomofthelowercrustnearMohoincentralandnortherntheBohaiseaalongtheTanlufault,andthesephenomenacouldbecausedbytheintrusionofmantlematerial,indicatingtheTanlufaultcouldbejustastheuprisingchannelofdeepmaterials.

简介：Ｔｈｅｓｐａｔｉａｌｔｅｍｐｏｒａｌｅｖｏｌｕｔｉｏｎｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｔｈｅｌｏａｄ／ｕｎｌｏａｄｒｅｓｐｏｎｓｅｒａｔｉｏ（ＬＵＲＲ）ａｎｄｉｔｓｉｍｐｌｉｃａｔｉｏｎｓｆｏｒｐｒｅｄｉｃｔｉｎｇｔｈｅｔｈｒｅｅｅｌｅｍｅｎｔｓｏ...

简介：Thisstudyinvestigatesdata-processingmethodsandexaminestheprecipitationeffectongravitymeasurementsattheDaligravitynetwork,establishedin2005.High-qualitygravitydatawerecollectedduringfourmeasurementcampaigns.Tousethegravitydatavalidly,somegeophysicalcorrectionsmustbeconsideredcarefully.Wefirstdiscussdata-processingmethodsusingweightedleastsquaresadjustmentwiththeconstraintoftheabsolutegravitydatum.Resultsindicatethatthegravityprecisioncanbeimprovedifallabsolutegravitydataareusedasconstraintsandifcalibrationfunctionsofrelativegravimetersaremodeledwithintheobservationfunction.Usingthisdata-processingscheme,themeanpointgravityprecisionisbetterthan12lgal.Afterdeterminingthebestdata-processingscheme,wethenprocessthegravitydataobtainedinthefourmeasurementcampaigns,andobtaingravitychangesinthreetimeperiods.Resultsshowthatthegravityhasaremarkablechangeofmorethan50lgalinthefirsttimeperiodfromApr–Mayof2005toAug–Septof2007.Tointerpretthelargegravitychange,ameanwatermasschange(0.6minheight)isassumedintheETOPO1topographicmodel.Calculationsoftheprecipitationeffectongravityshowthatitcanreachthesameorderoftheobservedgravitychange.ItisregardedasamainsourceoftheremarkablegravitychangeintheDaligravitynetwork,suggestingthattheprecipitationeffectongravitymeasurementsmustbeconsideredcarefully.

简介：AnM=6.0earthquakeoccurredonFebruary23,2001inthewesternSichuanProvince,China.Themacroseismicepicentersituatedinthehighmountain-narrowvalleyregionbetweenYajiangandKangdingcounties.Accordingtofieldinvestigationintheregion,theintensityofepicentralareareachedVIIIandtheareaswithintensityVIII,VIIandVIare180km2,1472km2and3998km2,respectively.TheisoseismalsaregenerallyinellipticshapewithmajoraxistrendingnearN-Sdirection.TheearthquakedestroyedmanybuildingsandproducedsomephenomenaofgroundfailureandmountainousdisastersintheareawithintensityVIII.Thiseventmayberesultedfromlong-termactivitiesoftheLitangfaultandYunongxifault,twomainfaultsinthewesternSichuan.Themovementsbetweenthemainfaultsmadethecruststressadjustedandconcentrated,andfinallytheearthquakeonasecondaryfaultintheblockreleasedaquitelargeenergy.

简介：Inordertounifythetimeandthespaceattributesintotemporal-spatialdistance,thetemporal-spatialproportionalcoefficientfTSisproposedinthispaper.Inaccordancewiththenewdistanceconcept,thetemporal-spatialcorrelativitywithintemporaldoubletsofstrongearthquakesinNorthChinaanditsvicinitysinceAD1500hasbeenanalyzed.ThecomputationresultsindicatethatdoubletsofstrongearthquakecanbedividedintotwogroupswhenfTSisendowedwith10km/ainthenewdistanceformula.Thetemporal-spatialdistancebetweentwopointsofdoubletgenerallycannotexceed140kmwhentwostrongquakesindoublethavesomecausativerelation.Andthosedoubletswithtemporal-spatialdistanceexceeding280kmareprobablyindependentseismiceventsindoublets.Thischaractercanbethereferencetothemigrationlawsummarizationandtrendprediction.

简介：Inthispaper,wemadeasystematicstudyonmorethan40yearsofobservationaldataoftentemporaryfault-crossingmeasurementsitesinthecapitalcircleregionofChina.Wecalculatedhorizontalandvertica1componentsoffaultslip,andhorizontalextensionorcompressioncomponents.Consideringthetectoniccharacteristicsofthecapitalcircleregionandregionalseismicity,weanalyzedthepresentfaultactivityofthecapitalcircleregionandtherelationshipwithearthquakes.Theresultsshowthecomplexityoffaultactivityintheregion:thelevelofactivityofallfaultsislow,mostfaultsareleft-lateralstrike-slipfaults;thereislessverticalactivitythanhorizontalactivityandcrustalmovementiscontrolledbyhorizontalmovement;faultactivityandearthquakeactivityhaveacertainrelationship,regionalfaultactivityincreasesbeforeanearthquake,andfaultactivityhascertainabnormalfeaturesbeforestrongearthquakes.

简介：The2010YushuMS7.1earthquakeoccurredinGanzi-Yushufault,whichisthesouthboundaryofBayanHarblock.Inthisstudy,byusingdoubledifferencealgorithm,thelocationsofmainshock(33.13°N,96.59°E,focaldepth10.22km)andmorethan600aftershockswereobtained.ThefocalmechanismsofthemainshockandsomeaftershockswithMS>3.5wereestimatedbyjointlyusingbroadbandvelocitywaveformsfromGlobalSeismicNetwork(GSN)andQinghaiSeismicNetworkaswell.Thefocalmechanismsandrelocationshowthatthestrikeofthefaultplaneisabout125°(WNW-ESE),andthemainshockisleft-laterallystrike-slip.Theparametersofshear-wavesplittingwereobtainedatseismicstationsofYUSandL6304bysystematicanalysismethodofshear-wavesplitting(SAM)method.Basedontheparametersofshear-wavesplittingandfocalmechanism,thecharacteristicsofstressfieldinseismicsourcezonewereanalyzed.ThedirectionsofpolarizationatstationsYUSandL6304aredifferent.ItisconcludedthatafterthemainshockandtheMS6.3aftershockonApril14,thestress-fieldwaschanged.