Full waveform inversion of the crust and upper mantle beneath the East Asia Continent and Western Pacific Subduction Zone

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<p>We present a three-dimensional transversely isotropic velocity model of the crust and upper mantle beneath the East Asia Continent and Western Pacific subduction zone based on the full waveform inversion (FWI). It minimizes waveform shape misfit between the synthetics and the observations from a large dataset, with 142 earthquakes recorded by about 2,000 broadband stations in East Asia. Compared to the previous models, the new FWI model, East Asia Radial Anisotropy Model 2020 (EARA2020) after 20 iterations shows much stronger wave speed perturbations within the imaged slabs including the Japan, Kuril, Izu-Bonin, Ryuku slabs. The high wave speed anomalies of the subducted slabs have a maximum perturbation of 8% for Vp and 13% for Vs. We have also systematically analyzed the slabs’ morphology, the intraplate tectonic structures including the North China Craton, the Sichuan Basin, and the Songliao Basin. and investigated the origin of four typical intra-continent volcanos in the continent of China including the Hainan volcano, Changbaishan volcano, Tengchong volcano, and Datong volcano.</p>