简介：Accordingtotheresultsofsiteseismichazardanalysisaccomplishedinthepastdecades,96site-relateddesignspectraareselectedassamplesinthisstudy.Theresultshowsthatthevalueofthecornerperiod(Tg)ofthedesignspectruminGBJ11-89(ChinaSeismicBuildingCode,issuedin1989)islowerthanthevalueobtainedbysiteseismichazardanalysis.ThesamesituationexistswhenwecomparethedesignspectraoftheCodestothespectraaccordingtotheearthquakerecords.Thevalueincurrentseismicdesigncode,GBJ50011-2001issuedin2001,isgreaterthanthatinGBJ11-89,butstilllessthanthevalueobtainedbysiteseismichazardanalysis.Ifweacceptthevaluegotbysiteseismichazardanalysis,wehaveasuspicionthat2/3ofbuildingsbuiltaccordingtoGBJ11-89willnotbesafewhenanearthquakewith2%probabilityofexceedancein50yearsoccurs.

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：Earthquake-relatedelectromagneticobservationaimsatfindingabnormalelectromagneticvariationassociatedwithearthquakepossibly.Theexistingstudieshaveprovedthatthismethodis,toalargeextent,effectiveinshort-termandimpendingearthquakepredication.Thispapersummarizesprogressanddiscussessomerelatedproblemsinthisfield.Somerequirementsforobservationsystemhavebeenproposedtoimprovemonitoringlevel.AsacaseobservationusingthereformedobservationsysteminJinghaiseismologicstation,Tianjin,someresultsaregiven.

简介：CorrelationamongvariousseismologicalpredictionindexesrelatedtoearthquakefrequencyNorenergyEfordescribingseismicitychangesisstudiedbyseismicdataof11seismiczones(areas)intheSichuan-Yunnanregion.Astatisticaltestforcorrelativityshowsthatseismicityindexesobtainedfromtransformationofearthquakefre-quencyNorenergyEhavecorrelationtoacertainextentwhiletheyareusedtodescribeseismicitychanges.Ifthetransformationislinearinallcases,thecorrelationcoefficientisequalto1.Thesmallerthetransformationdevia-tionfromlinearity,thebiggerthecorrelationcoefficientis.

简介：Basedonthecasestudiesandstatisticalanalysisofearthquake-relatedionosphericdisturbancesmainlyfromDEMETERsatellite,ground-basedGPSandionosoundingdata,thispapersummarizesthestatisticalcharacteristicsofearthquake-relatedionosphericdisturbances,includingelectromagneticemissions,plasmaperturbationsandvariationofenergeticparticleflux.AccordingtothemainresultsdonebyChinesescientists,fusingwiththeexistedstudyfromglobalresearches,seismo-ionosphericdisturbancesusuallyoccurredafewdaysorhoursbeforeearthquakeoccurrence.Parallelingtothesecasestudies,lithosphere-atmosphere-ionosphere(LAI)couplingmechanismsarecheckedandoptimized.Athermo-electricmodelwasproposedtoexplaintheseismo-electromagneticeffectsbeforeearthquakes.Apropagationmodelwasputforwardtoexplaintheelectromagneticwavesintotheionosphere.Accordingtotherequirementofearthquakepredictionresearch,Chinaseismo-electromagneticsatellite,thefirstspace-basedplatformofChineseearthquakestereoscopicobservationsystem,isproposedandplannedtolaunchatabouttheendof2014.ItfocusesoncheckingtheLAImodelanddistinguishingearthquake-relatedionosphericdisturbance.ThepreliminarydesignforthesatellitewilladoptCAST-2000platformwitheightpayloadsonboard.Itisbelievedthatthesatellitewillworktogetherwiththegroundmonitoringnetworktoimprovethecapabilitytocaptureseismo-electromagneticinformation,whichisbeneficialforearthquakemonitoringandpredictionresearches.

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