Brad Aagaard

This article reports a study of modeled, long-period building responses to ground-motion simulations of earthquakes in the San Francisco Bay Area. The earthquakes include the 1989 magnitude 6.9 Loma Prieta earthquake, a magnitude 7.8 simulation of the 1906 San Francisco earthquake, and two hypothetical magnitude 7.8 northern San Andreas fault earthquakes with hypocenters north and south...

We estimate the ground motions produce by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups...

We study how enforcing self-consistency in the statistical properties of the preshear and postshear stress on a fault can be used to constrain fault constitutive behavior beyond that required to produce a desired spatial and temporal evolution of slip in a single event. We explore features of rupture dynamics that (1) lead to slip heterogeneity in earthquake ruptures and (2) maintain...

We compute ground motions for the Beroza (1991) and Wald et al. (1991) source models of the 1989 magnitude 6.9 Loma Prieta earthquake using four different wave-propagation codes and recently developed 3D geologic and seismic velocity models. In preparation for modeling the 1906 San Francisco earthquake, we use this well-recorded earthquake to characterize how well our ground-motion...

With advances in computational capabilities and refinement of seismic wave-propagation models in the past decade large three-dimensional simulations of earthquake ground motion have become possible. The resulting datasets from these simulations are multivariate, temporal and multi-terabyte in size. Past visual representations of results from seismic studies have been largely confined to...

Regional gravity data in the northern San Francisco Bay region reflect a complex basin configuration beneath the Santa Rosa plain that likely contributed to the significant damage to the city of Santa Rosa caused by the 1969 M 5.6, 5.7 Santa Rosa earthquakes and the 1906 M 7.9 San Francisco earthquake. Inversion of these data indicates that the Santa Rosa plain is underlain by two...