Ricardo Taborda

For the past three years we have presented results of several large-scale earthquake simulations run by different research groups, but these have been limited to qualitative comparisons. This work presents a preliminary verification of three simulation sets for the ShakeOut earthquake scenario, version 1.1, an Mw 7.8 earthquake on a portion of the San Andreas fault in southern California. Two of the simulation sets use a finite difference approach while the third uses finite elements. The verification is done quantitatively by means of the goodness-of-fit criteria proposed by Anderson (2004) and the misfit criteria proposed by Kristekova et al. (2006). The results indicate good agreement between the three implementations. The metrics of the comparisons for ten selected locations throughout the region indicate that the agreement can be regarded as excellent according to the scale defined by Anderson. All three groups used a common discrete representation of SCEC’s Community Velocity Model (CVM, version 4). Discrepancies observed between the different synthetics are associated to intrinsic differences between the numerical methods used and their implementation by each simulation group. We conclude that the three schemes are consistent, reliable, and sufficiently accurate for future large-scale simulations.