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09/14/2006, 10:15 AM - 11:00 AM
Speaker:
Ewa Deelman, USC Information Sciences Institute.
The Southern California Earthquake Center (SCEC), is a multi-institution, multi-disciplinary center bringing together geo-scientists and computer scientists from over 54 institutions to develop, gather, and assemble new information about earthquakes in the Southern California region, developing a comprehensive and predictive understanding of earthquakes and to disseminate this information in ways that increase awareness, reduce economic losses and save lives.
Central to SCEC research is the establishment and operation of the SCECgrid at SCEC, USC, USC/ ISI. Through the use of standardized Globus-based middleware, the SCECgrid provides access to the TeraGrid computational and storage infrastructure. A grid-based workflow engine is an essential component of our research, and is based on the Virtual Data System (VDS), the Pegasus meta-scheduler system, the Replica Locator Service (RLS), Condor and the Globus toolkit. Grid tools have pushed SCEC results in two key areas 1) hazard calculations 2) development of an Earthworks portal.
Traditional PSHA calculations have been calculated using intensity measure relationships based on empirical attenuation relationships. The increased computational and storage capabilities of the SCECgrid has enabled development of physics-based probabilistic seismic hazard analysis (PSHA) calculations known as CyberShake for several sites in Southern California- a first in this field. This physics-based approach to PSHA, using waveform modeling, could lead to a more accurate understanding of the seismic risk for the region. This ongoing work will result in a comprehensive, accurate seismic hazard map for the region unlike anything that exists now. The CyberShake calculations require on the order of 15k CPU hours, 1 TB of data storage, and hundreds of thousands of files for each site studied. In our presentation, we will detail the geophysical models, the computational steps, and the calculations involved in a CyberShake hazard curve calculations. We will also describe how Globus, Condor, VDS, and Pegasus have been integral into this research project and how they have helped to produce key results.
The SCEC Earthworks Science Gateway allows SCEC users to perform complex, sophisticated, well-validated wave propagation simulations without requiring prior experience with high performance distributed computing. The SCEC Earthworks Science Gateway uses the same VDS and Pegasus-based workflow engine as used for CyberShake. An initial implementation of the SCEC Earthworks Science Gateway enables SCEC geoscientists to submit earthquake wave propagation simulation workflows for execution across the SCECgrid and the TeraGrid. Our presentation will cover the interface, the capabilities, community feedback, and future plans for this workflow-based science gateway.
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