This award provides one-half support of the costs of building a cluster of networked PC's (so called Beowulf cluster) for research in theoretical and applied seismology at Caltech. Jeroen Tromp and John Shaw have recently joined the faculty at Caltech after serving for several years on the faculty at Harvard University. They will build a 78 dual-CPU node Beowulf cluster with 78 Gb of RAM. The cluster will be used to run Tromp's spectral element code that has been specifically designed to run on multi-processor machines. The spectral element method represents one of the most comprehensive and robust algorithms for modeling seismic wave propagation though deep sedimentary basins (i.e. the Los Angeles basin) and for predicting the amplitude of strong ground motions that result from varying earthquake source parameters. Beowulf clusters represent a cost effective alternative to expensive shared-memory machines for high resolution modeling of large geophysical data sets. ***
