Crustal structure beneath Liaoning province and the Bohai Sea and its adjacent region in China based on ambient noise tomography

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    摘要 ThevelocitystructureofthecrustbeneathLiaoningprovinceandtheBohaiseainChinawasimagedusingambientseismicnoiserecordedby73regionalbroadbandstations.Allavailablethree-componenttimeseriesfromthe12-monthspanbetweenJanuaryandDecember2013werecross-correlatedtoyieldempiricalGreen'sfunctionsforRayleighandLovewaves.PhasevelocitydispersioncurvesfortheRayleighwavesandtheLovewavesweremeasuredbyapplyingthefrequencytimeanalysismethod.DispersionmeasurementsoftheRayleighwaveandtheLovewavewerethenutilizedtoconstruct2Dphase-velocitymapsfortheRayleighwaveat8–35speriodsandtheLovewaveat9–32speriods,respectively.BothRayleighandLovephase-velocitymapsshowsignificantlateralvariationsthatarecorrelatedwellwithknowngeologicalfeaturesandtectonicsunitsinthestudyregion.Next,phasedispersioncurvesoftheRayleighwaveandtheLovewaveextractedfromeachcellofthe2DRayleighwaveandLovewavephase-velocitymaps,respectively,wereinvertedsimultaneouslytodeterminethe3Dshearwavevelocitystructures.ThehorizontalshearwavevelocityimagesclearlyandintuitivelyexhibitthattheearthquakeswarmsintheHaichengregionandtheTangshanregionaremainlyclusteredinthetransitionzonebetweenthelow-andhigh-velocityzonesintheuppercrust,coincidingwithfaultzones,andtheirdistributionisverycloselyassociatedwiththesefaults.Theverticalshearwavevelocityimagerevealsthatthelowercrustdownwardtotheuppermostmantleisfeaturedbydistinctlyhighvelocities,withevenahigh-velocitythinnerlayerexistingatthebottomofthelowercrustnearMohoincentralandnortherntheBohaiseaalongtheTanlufault,andthesephenomenacouldbecausedbytheintrusionofmantlematerial,indicatingtheTanlufaultcouldbejustastheuprisingchannelofdeepmaterials.
    机构地区 不详
    出处 《地震学报:英文版》 2017年1期
    出版日期 2017年01月11日(中国Betway体育网页登陆平台首次上网日期,不代表论文的发表时间)
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