Visual Insights into High-Resolution Earthquake Simulations

Amit Chourasia, Steve Cutchin, Yifeng Cui, Reagan W. Moore, Kim B. Olsen, Steven M. Day, Jean B. Minster, Philip J. Maechling, & Thomas H. Jordan

Published 2007, SCEC Contribution #1085

Large weather and astrophysical simulations are performed on a regular basis. These simulations run on massively parallel machines and yield a wide variety of data products. The data products are then examined to gain insight and understanding of the simulated phenomena. Our study focuses on the visualization of a series of large earthquake simulations collectively called TeraShake. The simulation series aims to assess the impact of Southern San Andreas Fault earthquake scenarios on Southern California. The two simulation phases consist of seven production runs yielding a total of 100 TB of data. We discuss the role of visualization in gaining scientific insight and aiding unexpected discovery. Examples include significant differences in the ground motion pattern for different rupture directions, wave-guide effects leading to strong, localized amplification, variation in rupture speed for a spontaneous rupture model, and a �star burst� pattern indicating an unusual radiation of energy. We also cite instances of how visualization helped in finding numerical instabilities, leading to the use alternate absorbing boundary conditions for the wave propagation code. Without the sophisticated level of visualization carried out for the TeraShake simulations and described in this study, important scientific results would have remained undiscovered or less clearly understood. Moreover, some of the visualizations provide invaluable instructional material on earthquake phenomena to the public.

Citation
Chourasia, A., Cutchin, S., Cui, Y., Moore, R. W., Olsen, K. B., Day, S. M., Minster, J. B., Maechling, P. J., & Jordan, T. H. (2007). Visual Insights into High-Resolution Earthquake Simulations . IEEE Computer Graphics and Applications: Discovering the Unexpected, 27(5), 28-34. doi: 10.1109/MCG.2007.138.