A Research on the 2014 Wenzhou M4.2 Earthquake in the Shanxi Reservoir

(整期优先)网络出版时间:2017-04-14
/ 1
Completerecordsofmorethan3,000earthquakeeventsintheShanxi,WenzhoureservoirearthquakesequencewererecordedfromAugusttoNovember,2014bythehigh-density,high-resolutionmonitoringstationsoftheZhejiangRegionalDigitalSeismicNetworkandthereservoirearthquakemonitoringnetwork,withamaximummagnitudeofM4.2.Basedon3-Depicenterlocation,focalmechanismsolutions,andincombinationwiththegeologicalandtectoniccharacteristicsofthereservoirarea,theearthquakesequenceisdiscussedinthispaper.ThelinearfittingoftheHypoSATlocationresultsshowthatthemainshockoccurredintheNWtrendingfaultandtheearthquakesequenceisconcentratedinbandsalongtheactivefaults,withastrikeof305°,dippingSWwithdipangleof85°.ByusingP-wavefirstmotionsymbols,weobtainedtheaveragefocalmechanismofM≥3.5earthquakes,withastrike308°anddip84°fornodalplaneII.Thefieldgeologicalsurveyandresearchshowthatthestrike,dipandrakeofnodalplaneIIareroughlyconsistentwiththeoccurrenceoftheShuangxi-Jiaoxifault.ThecomprehensiveanalysisrevealsthattheNW-trendingShuangxi-Jiaoxifaultistheseismogenicstructureoftheearthquakes.