3D anelastic full waveform inversion and its application

Anelasticity is an intrinsic property of Earth’s interior and it is closely associated with temperature, partial melt, and water content. To date, the development of seismic attenuation models has lagged behind that of velocity models, due to the difficulty in distinguishing attenuation effects from velocity heterogeneities in waveforms, as well as inconsistencies across inversion methods and their resulting attenuation structures. To address these challenges, we recently developed a novel anelastic scattering-integral-based full waveform inversion (FWI) method. Its effectiveness has been verified through numerical experiments using the Northwestern United States region as a realistic case study. Specially, the method can accurately solve 3D anelastic wave equation even in the presence of strong attenuation and computes full anelastic sensitivity kernels incorporating both effects of physical dispersion and dissipation. As an application, we utilize abundant seismic waveform data from the China National Seismic Network to establish, for the first time, a high-resolution 3D anelastic structure model of the lithosphere and asthenosphere in the eastern Tibetan Plateau. Waveform comparisons and checkerboard tests verify the reliability of the inverted model, which achieves a maximum horizontal resolution of 0.6°×0.6°and a maximum vertical resolution of 25 km. This highly accurate anelastic model provides important structural constraints for understanding the deep processes of material extrusion at the eastern margin of the Tibetan Plateau.

This work is supported by the National Natural Science Foundation of China (42204056).