摘要
EarthquakeeventsfromtheIndonesiansubductionzonerecordedinnorthernAustraliashowalongandhigh-frequencycodaassociatedwithbothPandSwaves.RegionaleventsrecordedbyWarramungaarrayinnorthernAustraliacanseparateoutwavepropagationthroughthemantlebyfocusingonthecoherentsignalacrossthemedium-aperturearray.Mostoftheincoherentwavecomponentsresultfromstructuresinthevicinityofthearraywithsmall-scalelengthsof1–2kmorsmaller.Thecoherentphaseswithrelativelyrapidchangesinwaveformsareassociatedwiththescatteringofseismicwavesbycrustalandmantleheterogeneity,butinsomecasecanberelatedtostructuraleffectsnearthesource.Asthedepthofthesourceincreases,thecoherentportionoftheseismicwavefieldtendstobecomemuchsimpler,whichsuggeststhattheheterogeneitytendstoweakenatdepthwithlarger-scalelength.WecomparethecoherentsignalfeaturesofearthquakesfromtheIndonesiansubductionzonethathaveoccurredinrecentyearswiththoseintheearly1980s,firststudiedbyKennett(PhysEarthPlanetInter47:319–332,1987).Thegeneralcharacteristicsofthecoherentsignalvariationwithdepthinrecentyearsarethesameasthoseobservedin1980s,butthevariationsarelarger.Thischangesuggestsastringervariationinheterogeneitywithdepththanbefore,whichmaybearimportantinformationaboutthedynamicprocessesandevolutionofthecrustanduppermantle.
出版日期
2014年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
