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Evaluating Global Tomography Models With Antipodal Ambient Noise Cross‐Correlation Functions
Author(s) -
Xie Jun,
Chu Risheng,
Ni Sidao
Publication year - 2021
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1029/2020jb020444
Subject(s) - antipodal point , geology , rayleigh wave , tomography , seismology , noise (video) , amplitude , arc (geometry) , rayleigh scattering , surface wave , geophysics , geodesy , physics , geometry , optics , computer science , mathematics , artificial intelligence , image (mathematics)
It is essential to evaluate global tomography models, which provide important information for understanding Earth's structure and dynamics. Long‐period surface waves propagating between antipodal stations are good candidates for this purpose since they depend on global‐scale velocity variations in the upper mantle. In this study, we extract minor‐arc and major‐arc Rayleigh waves from ambient noise cross correlations between GEOSCOPE station AIS and ∼1,800 USArray stations near the antipode of AIS. We identify two Rayleigh‐wave‐focusing regions and simulate the observed maximum amplitude pattern at the antipodal region using synthetic surface waves based on three global tomography models. Our simulations suggest that seismic heterogeneity of the tomography models need to be inflated by a factor of 2–3 in oceanic regions to explain the observed focusing pattern of surface waves near the antipodal region.