Dr. Nian Wang, a Postdoctoral Fellow at U. Rhode Island, presents "3D full waveform modeling and inversion of anelastic models" at the MIT Earth Resources Laboratory.

Live video of this tralk will be available on ERL's Youtube Channel.

"Accurate and efficient forward modeling methods are important for simulation of seismic wave propagation in 3D realistic Earth models and crucial for high-resolution full waveform inversion. In the presence of attenuation, wave-field simulation could be inaccurate or unstable over time if not well treated, indicating the importance of the implementation of a strong stability preserving time discretization scheme. In this talk, I will discuss how to apply the fourth-order strong stability preserving Runge-Kutta (SSPRK) method with an optimal CFL coefficient to solve the anelastic wave equation. We perform theoretical and numerical analyses of the SSPRK method and find that the SSPRK has a larger stability condition number and can better suppress numerical dispersion compared with classical RK method. Then, we apply the scattering-integral method for calculating the travel time and amplitude sensitivity kernels with respect to velocity and attenuation structures. We show several synthetic tests to verify the effectiveness of the SSPRK method in generating accurate seismograms for forward modeling and accurate strain tensors for calculating sensitivity kernels. Finally, we apply our method to image anelastic structures (with concerns on the hotspot tracks) in the upper mantle of western United States and show some preliminary results."