简介:Thechangelawsofintensityofnearly200moderate-smallearthquakeswithMs=2.0~5.5occurringontheChinesemainlandsince1954havebeenanalyzedandarecomparedwiththatofmoderatelystrongearthquakes(Ms≥5.0).Theresultsshowthatthereisquiteobviousregionalityinthestatisticallawsbybothmoderate-smallearthquakesandmoderatelystrongearthquakes:attenuationofintensityinEasternChinaisslowerthanthatinWesternChinaandtheratioofthemajoraxistotheminoraxisofiso-seismallinesinEasternChinaissmallerthanthatinWesternChina.Theresultsalsoshowthatforafixedmagnitudetheattenuationofintensityofmoderate-smallearthquakesisfasterwhenintensityishigherthanV+andslowerwhenintensityislowerthanV-incomparisonwiththatofmoderatelystrongearthquakes.Furthermore,therealsohavebeensomedifferencesintheaspectsasintensity-magnituderelationbetweenstatisticallawsofmoderate-smallearthquakesandmoderatelystrongearthquakes.Thesedi
简介:Weappliedthedouble-differenceearthquakerelocationalgorithmto1348earthquakeswithM_S≥2.0thatoccurredinthenorthernTianshanregion,Xinjiang,fromApril1988toJune2003,usingatotalof28701P-andS-wavearrivaltimesrecordedby32seismicstationsinXinjiang.AimingtoobtainmostoftheseM_S≥2.0earthquakesrelocations,andconsideringtherequirementsoftheDDmethodandtheconditionofdata,weaddedthetraveltimedataofanother437earthquakeswith1.5≤M_S<2.0.Finally,weobtainedtherelocationresultsfor1253earthquakeswithM_S≥2.0,whichaccountfor93%ofallthe1348earthquakeswithM_S≥2.0andincludesalltheM_S≥3.0earthquakes.Thereasonfornotrelocatingthe95earthquakeswith2.0≤M_S<3.0isanalyzedinthepaper.Afterrelocation,theRMSresidualdecreasedfrom0.83sto0.14s,theaverageerroris0.993kminE-Wdirection,1.10kminN-Sdirection,and1.33kminverticaldirection.Thehypocenterdepthsaremoreconvergentthanbeforeanddistributedfrom5kmto35km,with94%beingfrom5kmto35km,68.2%from10kmto25km.Theaveragehypocenterdepthis19km.