Modeling 3-D wave propagation and finite slip for the 1998 Balleny Islands earthquake

• Published in: Journal of Geophysical Research: Solid Earth
• Main Authors: HjörleifsdÏŒttir, V., Kanamori, Hiroo, Tromp, Jeroen
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2009
• Subjects: Balleny Islands; source modeling
• Online Access: https://doi.org/10.1029/2008JB005975

We simulate surface waves in a 3-D Earth model using a spectral element method for existing kinematic source models of the M_W 8.1, 25 March 1998 Balleny Islands earthquake. The 3-D model incorporates lateral variations in the crust and mantle on the basis of models Crust2.0 and S20RTS. Our objective is to investigate the fit of the observed and simulated long-period surface waves in the hope of improving on the existing source models. We modify a body wave model determined by Henry et al. (2000) to improve the fit of long-period surface waveforms. We demonstrate that adding a smooth component of slip extending over a fault that connects the two subevents determined by Henry et al. (2000), without invoking slip on multiple fault planes or on unconnected fault patches, provides reasonable fits to long-period surface waves as well as body waves. © 2009 by the American Geophysical Union. Received 31 July 2008; revised 22 November 2008; accepted 11 December 2008; published 4 March 2009. We acknowledge support by the National Science Foundation under grant EAR-0711177. This is Seismolab contribution 10013. The numerical simulations for this research were performed on Caltech's Division of Geological and Planetary Sciences Dell cluster.We thank Göran Ekström for helpful suggestions. The comments of Keiko Kuge and an anonymous reviewer improved the manuscript. Index Terms: 7215 Seismology: Earthquake source observations (1240); 7290 Seismology: Computational seismology; 7230 Seismology: Seismicity and tectonics (1207, 1217, 1240, 1242); 7255 Seismology: Surface waves and free oscillations. Published - Hjoerleifsdottir2009p61510.10292008JB005975.pdf