An upper-mantle S-wave velocity model for East Asia from Rayleigh wave tomography

摘要: Abstract We present a new shear velocity model of the upper mantle beneath East Asia region derived by inverting Rayleigh wave group measurements between 10 and 145 s combined with previously published phase 150 250 s. dispersion curves along more than 9500 paths were measured to produce 2D maps for 10–145 periods. The benefit from inclusion data recorded China National Seismic Network surrounding global stations. increase in available has resulted enhanced resolution compared maps; horizontal across is about 3° periods used this study. shear-wave models indicate varying structure eastern China, which yields estimates lithosphere–asthenosphere boundary depth around 160 km Yangtze block approximately 140 western part North Craton (NCC), up depths 70–100 NCC, Northeast Cathaysia block. reveal subduction two opposite-facing continental plates under southern northern margin Tibet. An obvious low-velocity anomaly appears top 200 Tibet, inconsistent presence subducted Asian or Indian lithosphere Cenozoic volcanism fields Mongolian plateau are characterized an negative anomaly, but no signature deep-seated plume was observed.