C.7. Results of Prior NSF Research

Thomas H. Jordan and J. Bernard Minster. These geophysicists have been involved in a number of NSF-sponsored projects. THJ is P.I. of NSF Grant EAR-0049042 ("Western Deep Levels Gold Mine, South Africa, as a Natural Laboratory for Studying Rock Deformation Processes"), and JBM has participated in NSF Grant ATM-9873133 ("KDI: Structure Preserving Algorithms and Model Reduction in the Natural Sciences"). However, the most relevant project for this proposal is the NSF Cooperative Agreement for funding of the Southern California Earthquake Center [EAR-8920136]. Minster is the current Science Director of SCEC, and Jordan is SCEC board member for the University of Southern California. Jordan will assume the directorship of the Center on January 1, 2002.

Since 1991, SCEC has been the primary organization in Southern California for coordinating earthquake research. Among the most significant scientific accomplishments attained by scientists within this extended collaboration are the following:

• Seismic hazard science: Synthesis of seismic, geologic, and geodetic data to estimate earthquake potential. Procedure for balancing seismic and tectonic moment rates, including allowance for blind thrusts and off-fault earthquakes. Recognition of hazard-estimate sensitivity to magnitude distribution and non-Poissonian recurrence.
• Los Angeles Basin hazard: Fundamental reformulation of tectonics and seismic hazard of the L.A. Basin, including recognition of blind thrusts and the potential for very large (magnitude 7+) earthquakes.
• Strong ground motion: Improved understanding of how sedimentary basins influence earthquake ground motion -- focusing effects in Santa Monica, sediment nonlinearity from the Northridge earthquake, and basin-depth/edge effects -- and the effects of surface deposits on ground shaking. Matching of low-frequency ground-motion amplitudes from Northridge using three-dimensional wave-propagation simulations.
• Landers earthquake: Joint inversion of multiple data sets to determine rupture history of a large earthquake. Demonstration of rupture propagation by dislocation pulse, rather than expanding crack. Detailed observations and physical modeling of post-seismic relaxation and the effects of fault segmentation during large-scale rupture. Use of a dynamical rupture model to satisfy observed ground motions.
• Fault systems: Paleoseismic fieldwork, geodetic observations, and integrative studies showing clustering of large earthquakes, prolonged earthquake interactions, large cascading ruptures, and general consistency with the historical record.
• Deformation map: Development of a detailed crustal deformation map, combining all available geodetic data, and use of this map to investigate tectonic loading of faults and post-earthquake response. Recognition from geodetic data of rapid strain accumulation in the eastern Ventura basin prior to the Northridge earthquake.
• Evolution of stresses and slip deficits: Modeling of stress evolution due to earthquakes, tectonic motions on faults, and stress relaxation. Demonstration that some earthquake sequences are consistent with triggering by stress interactions. Recognition of seismic slip deficits on faults in the Ventura and Los Angeles basins.
• Los Angeles Basin structure from LARSE: Discovery of a mid-crustal reflector (possible detachment zone) under the San Gabriel Mountains, apparent offset of the crust-mantle transition under the San Andreas Fault, and the displacement of the crustal root north of the topographic maximum. Revision of the depths of the San Gabriel and Los Angeles sedimentary basins.
• Fault-zone waves: Demonstration of the existence of waves trapped by fault-zone low-velocity waveguides and use of these waves in determining fault-zone properties and observing the fault-zone healing after earthquakes.
• 3D seismic velocity model: Development of a 3D velocity model that includes geologic constraints, sedimentary basins, tomographic background velocities, a detailed geotechnical surface layer, and topography on the crust-mantle boundary. Demonstration that this model is consistent with independent gravity measurements.

  These and other scientific results have been published in more than 500 scientific articles and special publications. The results have been synthesized into a "Master Model" of probabilistic seismic hazard in the Los Angeles region through a series of integrative reports:

• Phase I: Future Seismic Hazards in Southern California, Implications of the 1992 Landers Earthquake Sequence.
• Phase II: Seismic Hazards in Southern California: Probable Earthquakes, 1994 to 2024.
• Phase III: Accounting for Site Effects in Probabilistic Seismic Hazard Analyses of Southern California.
• Phase IV: RELM: Regional Earthquake Likelihood Models.

SCEC has organized and obtained funding for major new facilities in Southern California. The 250-station Southern California Integrated GPS Network (SCIGN) is the world's second-largest (behind Japan), making continuous, densely spaced geodetic measurements of strain accumulation and release in the L.A. Basin and surrounding regions. The Southern California Earthquake Data Center (SCEDC) is the primary data repository and distribution center for seismic networks in the region. The Portable Broadband Instrument Center (PBIC) provides high-performance seismic instrumentation for field experiments and post-seismic response.

Along with these facilities, SCEC has constructed a new infrastructure that allows researchers to share data, instruments, expertise, and effort. It has developed on-line data archives for all available seismic records, geodetic data, and satellite radar images for Southern California, and established the first on-line, web-based relational database for retrieving strong-motion data. It coordinated the field observations and science analysis following the 1992 Landers, 1994 Northridge, and 1999 Hector Mine earthquakes, and provided much of the expertise for post-event response to the damaging 1999 Turkey earthquakes. SCEC's most enduring accomplishment may be the demonstration that an effective, organized collaboration among disciplines is the best way to make progress in understanding earthquakes and communicating this understanding to others.

Carl Kesselman (CCR-8899615) (NSF-ASC 96-19020 Center for Research in Parallel Computation). Funding provided under this NSF funded science and technology center was used to conduct research in parallel programming languages and the Nexus runtime system. This work let to the development of the development of the Globus toolkit which provides mechanisms for communication, resource management, security, data access, and information in high-performance distributed environments. Globus is used extensively within the National Technology Grid being established by the two NSF PACIs as well as by many NSF-supported research projects. (NSF ASC 96-1920 National Partnership for Advanced Computational Infrastructure) Funding from this PACI center was used to deploy Globus in production environments, and develop advanced Grid applications. Kesselman is also part of the CGrADS project (NSF-EIA 9975020), which is investigating the construction of Software development environments for Grid applications. Work in GrADS has focused on the development of so called virtual organization tools for structuring Grid based execution environments for program execution. Finally, as senior personal on the GriPhyn Project (NSF ITR-0086044), Kesselman is leading research in the use of "virtual data" as a basic usage paradigm for data-intensive science.

Reagan Moore. The development of advanced systems for data, information, and knowledge management has been conducted under multiple NSF supported projects. The primary project is the NSF National Partnership for Advanced Computational Infrastructure, and supplements to the NPACI project from NARA for persistent archives and NASA for an Information Power Grid. Ongoing NSF projects include the Digital Library Initiative Phase 2, the National Science, Mathematics, Engineering, and Technology Education Digital Library, and the Grid Physics Network. Across the multiple projects, SDSC has focused on development of common software infrastructure for creating digital libraries, data grids, and persistent archives. The approach is based upon the concepts of logical representations for digital objects (global name space), logical representations for storage systems (uniform access semantics across file systems, archives, and databases), and logical representations for information repositories (automation of SQL generation, export of attributes as XML DTDs, and support for extensible schema). The resulting data and information management system is the SDSC Storage Resource Broker. The software supports collections distributed across network connected archives, file systems, and databases. Applications of the SRB include replication of the 2-Micron All Sky Survey (5 million images, 10 TBs) using containers, integration of collections into a virtual data grid as part of GriPhyN, and federation of neuroscience brain image collections. The SRB software is unique in that it provides the interoperability mechanisms needed to federate access to heterogeneous storage resources, as well as the management of digital objects that are distributed across the storage resources. A persistent archive is created by providing the ability to migrate digital objects from old storage technologies to new technologies, and collections from old databases to new databases. Reports on the capabilities of the system have been published in conferences, government workshops, and in project final reports.

Proposal: Table of Contents

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