HR: 15:25h
AN: S23C-08    [Abstracts]
TI: New Airborne LiDAR Survey of the Hayward Fault, Northern California
AU: * Brocher, T M
EM: brocher@usgs.gov
AF: U. S. Geological Survey, 345 Middlefield Road, MS 977, Menlo Park, CA 94025, United States
AU: Prentice, C S
EM: cprentice@usgs.gov
AF: U. S. Geological Survey, 345 Middlefield Road, MS 977, Menlo Park, CA 94025, United States
AU: Phillips, D A
EM: phillips@unavco.org
AF: UNAVCO, 6350 Nautilus Drive, Boulder, CO 80301, United States
AU: Bevis, M
EM: mbevis@osu.edu
AF: School of Earth Sciences, Ohio State University, 125 South Oval Mall, Columbus, OH 43210, United States
AU: Shrestha, R L
EM: rshre@ce.ufl.edu
AF: Dept. Civil and Coastal Engineering, University of Florida, PO Box 116580, Gainsville, FL 32611, United States
AB: We present a digital elevation model (DEM) constructed from newly acquired high-resolution LIght Detection and Ranging (LIDAR) data along the Hayward Fault in Northern California. The data were acquired by the National Center for Airborne Laser Mapping (NCALM) in the spring of 2007 in conjunction with a larger regional airborne LIDAR survey of the major crustal faults in northern California coordinated by UNAVCO and funded by the National Science Foundation as part of GeoEarthScope. A consortium composed of the U. S. Geological Survey, Pacific Gas & Electric Company, the San Francisco Public Utilities Commission, and the City of Berkeley separately funded the LIDAR acquisition along the Hayward Fault. Airborne LIDAR data were collected within a 106-km long by 1-km wide swath encompassing the Hayward Fault that extended from San Pablo Bay on the north to the southern end of its restraining stepover with the Calaveras Fault on the south. The Hayward Fault is among the most urbanized faults in the nation. With its most recent major rupture in 1868, it is well within the time window for its next large earthquake, making it an excellent candidate for a "before the earthquake" DEM image. After the next large Hayward Fault event, this DEM can be compared to a post-earthquake LIDAR DEM to provide a means for a detailed analysis of fault slip. In order to minimize location errors, temporary GPS ground control stations were deployed by Ohio State University, UNAVCO, and student volunteers from local universities to augment the available continuous GPS arrays operated in the study area by the Bay Area Regional Deformation (BARD) Network and the Plate Boundary Observatory (PBO). The vegetation cover varies along the fault zone: most of the vegetation is non-native species. Photographs from the 1860s show very little tall vegetation along the fault zone. A number of interesting geomorphic features are associated with the Hayward Fault, even in urbanized areas. Sag ponds and push up ridges can easily be followed along the fault zone, as well as more subtle features. Landslides along the western flanks of the East Bay Hills were also imaged. We expect that these new LIDAR images will allow us to detect subtle geomorphic features associated with active faulting that may reveal previously undetected active strands or better delineate active strands in areas of pervasive landsliding (as well as better mapping of the landslides themselves). We also anticipate that they will aid in land use planning and identification of new paleoseismic sites. The LIDAR data are freely available at www.earthscope.org.
UR: http://www.earthscope.org/
DE: 1209 Tectonic deformation (6924)
DE: 7221 Paleoseismology (8036)
DE: 7250 Transform faults
DE: 8002 Continental neotectonics (8107)
DE: 8040 Remote sensing
SC: Seismology [S]
MN: 2007 Fall Meeting