NBW: Computational Seismology: Narrowing the Gap Between Theory and Observations

Numerical solutions to the problem of seismic wave propagation, that allow simulations of complete wave fields through 3D structures, are currently revolutionizing seismology and related fields. So far - in order to calculate theoretical seismograms in the observed frequency bands - one had to resort to solution methods with severe limitations (e.g., ray theoretical approximations, one-dimensional structures, perturbation theory, etc.). Only in the past few years, computational power has allowed us to simulate wave fields that can be directly compared to observations. Even though the computations still require substantial resources, the methodologies developed in the past decade are beginning to enter routine processing steps in all branches ranging from exploration seismics to global seismology. Here we present recent examples in global seismology (spectral element modeling of global wave propagation) and earthquake scenario simulations, their relation to shaking hazard estimation, and associated problems. The next decade will see fundamental changes in the way data fitting (inverse problem, parameter estimation) is done in seismology with the potential of advances in several fields of Earth Sciences.