Crustal S-wave velocity structure of the Yellowstone region using a seismic ambient noise method

(整期优先)网络出版时间:2013-05-15
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TheYellowstonevolcanoisoneofthelargestactivevolcanoesintheworld,anditspotentialhazardsdemanddetailedseismologicalandgeodeticstudies.Previousstudieswithtraveltimetomographyandreceiverfunctionshaverevealedalow-velocitylayerinthecrustbeneaththeYellowstonevolcano,suggestingthepresenceofamagmachamberatdepth.Weuseambientseismicnoisefromregionalseismicstationstoretrieveshort-periodsurfacewavesandthenstudytheshallowshearvelocitystructureoftheYellowstoneregionbysurfacewavedispersionanalysis.WefirstobtainedacrustalmodeloftheareaoutsideoftheYellowstonevolcanoandthenconstructedanabsoluteshearwavevelocitystructureincombinationwithreceiverfunctionresultsforthecrustbeneaththeYellowstonevolcano.Thevelocitymodelshowsalow-velocitylayerwithshearvelocityataround1.3km/s,suggestingthatalarge-scalemagmachamberexistsatshallowlevelswithinthecrustoftheYellowstonevolcanicregion.