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.