简介:OnApril20th,2013,anearthquakeofmagnitudeMW6.6occurredatLushanofSichuanonthesouthernsegmentoftheLongmenshanfaultzone,withnotypicalcoseismicsurfacerupture.Thisworkplottedanisoseismalmapoftheearthquakeafterrepositioningover400post–earthquakemacro–damagesurveypointsfrompeakgroundacceleration(PGA)datarecordedbytheSichuanDigitalStrongEarthquakeNetwork.ThismapindicatesthattheLushanearthquakehasadamageintensityofIXontheLieduscale,andthatthemeizoseismalareadisplaysanoblateellipsoidshape,withitslongitudinalaxisintheNEdirection.Noobviousdirectivitywasdetected.Furthermore,therepositioningresultsof3323earlyaftershocks,seismicreflectionprofilesandfocalmechanismsolutionssuggeststhatthemajorseismogenicstructureoftheearthquakewastheDayiFault,whichpartlydefinestheeasternMengshanMountain.ThisearthquakeresultedfromthethrustingoftheDayiFault,andcausedshorteningofthesouthernsegmentoftheLongmenshanintheNW–SEdirection.CoseismalrupturewasalsoproducedinthedeepoftheXinkaidianFault.Basedontheaboveseismogenicmodelandthepresentationofcoseismicsurfacedeformation,itisspeculatedthatthereisariskofmoremajorearthquakesoccurringinthisregion.更多还原