HR: 17:15h
AN: H34B-06    [Abstracts]
TI: Tectonic and geomorphic controls on littoral sediment distribution and transport along an emergent, rocky coastline: Northern Monterey Bay, California
AU: * Storlazzi, C D
EM: cstorlazzi@usgs.gov
AF: U.S. Geological Survey, USGS Pacific Science Center 400 Natural Bridges Drive, Santa Cruz, CA 95060, United States
AU: Anima, R J
EM: ranima@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road MS-999, Menlo Park, CA 94025,
AU: Finlayson, D P
EM: dfinlayson@usgs.gov
AF: U.S. Geological Survey, USGS Pacific Science Center 400 Natural Bridges Drive, Santa Cruz, CA 95060, United States
AB: Two hydrographic surveys produced high-resolution images of the inner shelf of northern Monterey Bay, Santa Cruz County, CA. Interferometric side-scan swath bathymetric sonar data were combined with sub-bottom seismic profiles, aerial imagery, high-resolution topography, and local geology to better understand how coastal geomorphology, lithology, and tectonics influence the distribution and transport of littoral sediment in the nearshore and inner shelf along a rocky shoreline. The survey data showed that the inner shelf along an emergent, high-energy rocky coastline is extremely varied in nature, being characterized by a mosaic of flat sandy areas, boulder fields and complex bedrock ridges that support rich marine ecosystems. We interpret the distribution of littoral sediment along this coastline to be primarily controlled by the northwest-trending structure of the region. Because of the structural barriers to littoral transport, high-energy wave events are required to mobilize sediment to a great enough height in the water column so that it can be transported over the bedrock highs between adjacent pocket beaches. Accordingly, the timing and magnitude littoral sediment transport along rocky coasts appears to be dictated by the episodic nature of storm activity, more so than along linear, sandy coasts where these structural barriers are much smaller or do not exist.
DE: 3022 Marine sediments: processes and transport
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 4217 Coastal processes
DE: 4558 Sediment transport (1862)
DE: 8106 Continental margins: transform
SC: Hydrology [H]
MN: 2007 Fall Meeting