A 2D joint inversion method for Rayleigh wave phase velocity and attenuation coefficient

Seismic attenuation is important to understand the thermal and compositional state of the lithosphere, therefore sheds light on its deformation process. However, measuring the attenuation coefficient of seismic waves is still a challenging task because the phase and amplitude can be affected by both elastic velocity structures and anelastic attenuation, let alone these effects are coupled. Here, we developed a 2D joint inversion T-matrix method for the Rayleigh-wave phase velocity and attenuation coefficient simultaneously. Using a matrix inversion calculation to update the background medium Green functions with scattering series, the scattered wavefield can be fully represented in the frequency domain. First, the T-matrix method takes the coupling of elasticity and attenuation on waveform into consideration by joint inversion. Secondly, by calculating the anelastic scattering effects, 2D distribution can be obtained even for weak attenuation, which is a step towards 3D Q structure. Without time domain wave propagation simulations, the method is affordable in regional problems. Therefore, the method can be used to invert 2D Rayleigh wave phase velocity and attenuation coefficients.