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Effects of 3D random correlated velocity perturbations on predicted ground motions

January 1, 2010

Three-dimensional, finite-difference simulations of a realistic finite-fault rupture on the southern Hayward fault are used to evaluate the effects of random, correlated velocity perturbations on predicted ground motions. Velocity perturbations are added to a three-dimensional (3D) regional seismic velocity model of the San Francisco Bay Area using a 3D von Karman random medium. Velocity correlation lengths of 5 and 10 km and standard deviations in the velocity of 5% and 10% are considered. The results show that significant deviations in predicted ground velocities are seen in the calculated frequency range (≤1 Hz) for standard deviations in velocity of 5% to 10%. These results have implications for the practical limits on the accuracy of scenario ground-motion calculations and on retrieval of source parameters using higher-frequency, strong-motion data.

Citation Information

Publication Year 2010
Title Effects of 3D random correlated velocity perturbations on predicted ground motions
DOI 10.1785/0120090060
Authors S. Hartzell, S. Harmsen, A. Frankel
Publication Type Article
Publication Subtype Journal Article
Series Title Bulletin of the Seismological Society of America
Series Number
Index ID 70037330
Record Source USGS Publications Warehouse
USGS Organization

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