简介：Aseismicarrayoftwentyfourseismometers(Qiaojiaarray)operatedbytheInstituteofGeophysics,ChinaEarthquakeAdministrationwassituatedalongtheZemuhefaultandthenorthendofXiaojiangfault,whichisapartoftheeastboundaryoftheChuan-Dian(Sichuan-Yunnan)rhombuscrustalmass.TheQiaojiaarraystartedoperationattheendofFebruary,2012.SincethentheApril20,2013LushanMS7.0earthquakeandtheAugust3,2014LudianMS6.5earthquakehaveoccurredinthevicinityoftheQiaojiaarray.TheearthquakecataloguerecordedbytheQiaojiaarraysinceMarch,2012isusedinthisstudy.ThetemporalvariationoftheearthquakecountbeforetheLushaneventandtheLudianeventisanalyzed.Theresultsareasfollows:①AverycleargraduallyincreasingvariationofthecountofM≥2.0earthquakeswithintheregion,whereallearthquakesrecordedbytheQiaojiaarraycoveragecanbefoundbeforetheLushaneventandtheLudianevent,andtheincreasingrangeanddurationofthecountbeforetheLudianeventarebothlargerthanthosebeforetheLushanevent.②IntheregioncoveredbytheQiaojiaarray,forearthquakeswithdepthh≤10kmarisingprocessofthecountwasmanifestedbeforebothevents,alongwithanearlysamedurationofaboutfiveandahalfmonths,andforearthquakeswithdepthsh>10kmarising-droppingprocessofthecountwasmanifestbeforetheLushanevent,beforewhichtherising-droppingprocessappearedagain.Thevariationofthecountforearthquakeswithdepthh≤10kmisthereverseofthatforearthquakeswithdepthh>10km.③WithinandneartheregioncoveredbytheQiaojiaarray,thevariationofthecountmanifestsarisingprocessforearthquakeswithdepthh≤10kmorh>10kmbeforetheLushaneventandonlyforearthquakeswithdepthh≤10kmbeforetheLudianevent.Thevariationofthecountmanifestsaweakeningprocessforearthquakeswithdepthh>10kmbeforetheLushanevent.Itisshownfromtheaboveresultsthattheseismicitywit