Full Waveform Elastodynamic-Based Earthquake Inversion on Supercomputers
We focus on the inverse problem of estimating the earth model from observations of ground motion from past earthquakes. We discuss such compounding issues as extreme large scale, ill-posedness, discontinuous solutions, multigrid preconditioners for the reduced Hessian, nonlinear convergence difficulties, and multiple local minima, as well as techniques for addressing them on multi-thousand processor terascale supercomputers. We end with a discussion of some outstanding challenges, and the conclusion that earthquake inversion to frequencies of engineering interest remains a major challenge for petascale computing.
Omar Ghattas, University of Texas at Austin