HR: 17:15h
AN: G12A-06    [PDF]
TI: Northern California LIDAR Data: A Tool for Mapping the San Andreas Fault and Pleistocene Marine Terraces in Heavily Vegetated Terrain
AU: * Prentice, C S
EM: cprentice@usgs.gov
AF: U.S.Geological Survey, 345 Middlefield Rd MS 977, Menlo Park, CA 94025 United States
AU: Crosby, C J
EM: Christopher.Crosby@asu.edu
AF: U.S.Geological Survey, 345 Middlefield Rd MS 977, Menlo Park, CA 94025 United States
AU: Harding, D J
EM: David.J.Harding@nasa.gov
AF: NASA, Goddard Space Flight Center, Mail Code 921, Greenbelt, MD 20771 United States
AU: Haugerud, R A
EM: rah@ess.washington.edu
AF: U.S.Geological Survey, Department of Earth and Space Sciences, Box 31310, University of Washington, Seattle, WA 98195 United States
AU: Merritts, D J
EM: dorothy.merritts@fandm.edu
AF: Franklin and Marshall College, Geosciences Department, Lancaster, PA 17604 United States
AU: Gardner, T W
EM: tgardner@trinity.edu
AF: Trinity University, Department of Geosciences, One Trinity Place, San Antonio, TX 78212 United States
AU: Koehler, R D
EM: koehler@lettis.com
AF: William Lettis and Associates, 999 Andersen Dr., Ste 120, San Rafael, CA 94901 United States
AU: Baldwin, J N
EM: baldwin@lettis.com
AF: William Lettis and Associates, 1777 Botelho Dr., Ste. 262, Walnut Creek, CA 94596 United States
AB: Recent acquisition of airborne LIDAR (also known as ALSM) data covering approximately 418 square kilometers of coastal northern California provides a powerful new tool for mapping geomorphic features related to the San Andreas Fault and coastal uplift. LIDAR data has been previously used in the Puget Lowland region of Washington to identify and map Holocene faults and uplifted shorelines concealed under dense vegetation (Haugerud et al., 2003; see http://pugetsoundlidar.org). Our effort represents the first use of LIDAR data for this purpose along the San Andreas Fault. This data set is the result of a collaborative effort between NASA Solid Earth and Natural Hazards Program, Goddard Space Flight Center, Stennis Space Center, USGS, and TerraPoint, LLC. The coverage extends from near Fort Ross, California, in Sonoma County, along the coast northward to the town of Mendocino, in Mendocino County, and as far inland as about 1-3 km east of the San Andreas Fault. The survey area includes about 70 km of the northern San Andreas Fault under dense redwood forest, and Pleistocene coastal marine terraces both north and south of the fault. The average data density is two laser pulses per square meter, with up to four LIDAR returns per pulse. Returns are classified as ground or vegetation, allowing construction of both canopy-top and bare-earth DEMs with 1.8m grid spacing. Vertical accuracy is better than 20 cm RMSE, confirmed by a network of ground-control points established using high-precision GPS surveying. We are using hillshade images generated from the bare-earth DEMs to begin detailed mapping of geomorphic features associated with San Andreas Fault traces, such as scarps, offset streams, linear valleys, shutter ridges, and sag ponds. In addition, we are using these data in conjunction with field mapping and interpretation of conventional 1:12,000 and 1:6000 scale aerial photographs to map and correlate marine terraces to better understand rates of coastal uplift, and rates of strike-slip motion across the San Andreas Fault.
DE: 1294 Instruments and techniques
DE: 7221 Paleoseismology
DE: 8107 Continental neotectonics
SC: Geodesy [G]
MN: 2003 Fall Meeting