Past Event: Oden Institute Seminar

Trans-dimensional full waveform inversion

Mrinal K. Sen, Professor, Institute for Geophysics, DGS, John A. and Katherine G. Jackson Chair in Applied Seismology, UT Austin

Abstract

Full waveform inversion (FWI) involves estimation of subsurface seismic wave velocity maps using complete waveform recordings. Typically this is solved by iterative gradient descent algorithms that are sensitive to the choice of starting models. We have developed an MCMC algorithm in which the number of model parameters is treated as a variable. It combines the reversible jump MCMC with the gradient based Hamiltonian Monte Carlo (HMC). We solve our forward problem using time-domain finite difference method while adjoint method is used to compute the gradient vector required at the HMC stage. Efficiency and usefulness of the algorithm are demonstrated using synthetic and field data examples. Bio Mrinal K. Sen is a professor of Geophysics and holder of Jackson Chair in Applied Seismology at the Department of Geological Sciences and concurrently serves as the associate director of the Institute for Geophysics at the University of Texas at Austin. During 2013 and 2014, Mrinal served as the director of the National Geophysical Research Institute, Hyderabad, India. His research interests include seismic wave propagation and inverse theory.