[Group A | Group B | Group D | Group E | Group F]

**Geologic Investigations of the August 17, 1999 Izmit, Turkey Earthquake:
The SCEC Group C Response**

Group C's efforts in the final two years of SCEC will center around five activities, as outlined below. With the exception of minor post-earthquake paleoseismic work in the vicinity of the Lavic Lake fault, all projects should be geared towards continuing or completing existing projects, and towards generation of summary information for the legacy document. Requests for support to help generate the legacy document itself should coordinated with the group leader and submitted as a separate proposal.

Task C1 - Paleoseismic research along the San Andreas fault. This ongoing mega-project is aimed at developing a long time-history of large earthquakes along the southern half of California's master fault. Successful proposals should advocate studies at sites with demonstrated potential to yield paleoseismic data, as all work must be completed and published in the next 2 years. Priority will be given to ongoing project sites that have already demonstrated success but need completion. A limited amount of funding may also be applied towards better defining the faults slip rate along the Mojave, San Bernardino, and Indio segments, and to more precise dating of events at new and previously studied sites.

Task C2 - Study of neotectonic and paleoseismic issues in the Los Angeles basin and surrounding urbanized region. This ongoing mega-project is expected to address both surface and subsurface problems, with special emphasis on the potential size of future seismicity. Specifically, it is expected that subsurface work will continue on the architecture of potential seismic sources in the urbanized L.A. basin, with emphasis on resolving the complex structural relationships in the Coyote Hills, Puente Hills, Montebello Hills and surrounding areas. Surface studies should continue to further resolve the timing of past earthquakes and late Quaternary slip rates on important surface faults of the region, and address the issue of size of past earthquakes by resolving slip per event. Priority will be given to completing ongoing studies in the areas of emphasis, and not initiating new endeavors.

Task C3 - Regional neotectonic and paleoseismic studies. This activity includes projects that would not be part of the two organized activities described above. Proposals must address fundamental problems or practical issues of seismic hazard evaluation and fault behavior. Subjects could include the evaluation of the geometry, styles and rates of important southern California structures and the dates and magnitude of their latest earthquakes; evaluation of the magnitude of aseismic permanent deformation; and fundamental observation-based studies of fault segmentation and the repetition of earthquake ruptures. Again, priority will be given towards completing ongoing studies, and those that can be successfully completed in two years.

Task C4 – Post-earthquake paleoseismic studies along the Lavic Lake and Bullion faults. This organized activity is designed to be operated in project mode between SCEC, the USGS and the CDMG. Successful proposals should focus on dating past earthquakes on the Lavic Lake, Bullion and nearby faults through collaborative trenching and field geomorphic studies. Funding for this task is limited.

Task C5 – Three-dimensional structural model of southern California. As part of its legacy document, SCEC wishes to develop the best up-to-date 3-D fault and geology model of the crust in southern California. Surface topography (DEM) should be included. Ideally the model should be web-based and use visualization software to view the model from different directions. The model may be broken down by seismotectonic province in order to improve the on-screen resolution. See also Task D8.