Application of Evolutionary Programming to Earthquake Hypocenter Determination

Jean B. Minster, Nadya Williams, Jennifer S. Haase, Freeman Gilbert, & Jennifer S. Haase

Published 1995, SCEC Contribution #212

As models of seismic velocity in the Earth’s crust are refined to accommodate larger and better data sets, they tend to become locally “rough” where they are best resolved, with nonplanar interfaces, and complex structures. This means that perturbation techniques which rely on differentiability of travel-times with respect to source coordinates are likely to fail, or to give erroneous results with little evidence that the answer is wrong. With even relatively simple three-dimensional structures involving dipping discontinuities, correct identification of seismic arrivals - or “phases” - can be problematic, and precise event locations elusive. We investigate the applicability of evolutionary programming to this problem and conclude that it yields satisfactory results, provided that no gross errors are present in the observations. Realistic applications to routine locations of earthquakes in a three-dimensional crustal model call for an effective ray tracing and travel time calculation strategy.

Citation
Minster, J. B., Williams, N., Haase, J. S., Gilbert, F., & Haase, J. S. (1995). Application of Evolutionary Programming to Earthquake Hypocenter Determination. Poster Presentation at 4th Annual Conference on Evolutionary Programming.