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

简介：Onthebasisoflocatingbythegeochemicalprospecting,shallowseismicsounding,drilling,geologicalprofiling,andneogeochronologicaldating,wefirstfoundoutthedislocationamountalongtheLiaocheng-LankaoburiedfaultsincetheQuaternaryandtheageofitslatestactivityphaseanddeterminedthattheupperbreakpointbythefaultdislocationreaches20mbelowthesurface.ThelatestactivityphasewasintheearlyHoloceneandthefaultisashallow-buriedactivefault.Anaveragedislocationratealongthefaultis0.12mm/asincetheQuaternary.Thus,itisaburiedactivefaultwithintermediatetostrongmovementstrengthintheeasternChina.

简介：Beforeastrongearthquake,thereisoftenaprocessofquiescenceor2absence2ofregionalseismicactivity,whichisaphenomenonthathasattractedtheattentionofmanyscholarsinChinaandothercountries(LU,etal,1985;Wesson,1973).Inthepastten-oddyears,someChineseseismologistsmade,earlierorlater,specialstudiesonthequiescenceanomalyofseismicityinsomespecifiedareasfromdifferentangles.TakingtheconvertedannualfrequencyofM=5.0earthquakesinNorthChinaregionasacharacteristicquantity,JIANGandFENG(1989)analyzedthequiescenceanomalyofseismicactivitybyfuzzyrecognition.