HR: 11:20h
AN: OS22B-05    [Abstracts]
TI: Size and Age Characteristics for West Coast Tsunamigenic Landslides
AU: * Lee, H J
EM: hjlee@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Normark, W R
EM: wnormark@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Fisher, M A
EM: mfisher@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Greene, H G
EM: greene@mlml.calstate.edu
AF: Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039 United States
AU: Kayen, R E
EM: rkayen@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Dartnell, P
EM: pdartnell@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Locat, J
EM: jlocat@ggl.ulaval.can
AF: Laval University, Medicene Street, Quebec, Qc G1K 7P4 Canada
AB: Multibeam bathymetric imagery is now available for a number of well-defined submarine landslide deposits along the west coast of the United States. Several of these landslides are known to have caused damaging tsunamis and others are of sufficient size to have generated tsunamis when they occurred, assuming that their motion was rapid. These failures are located off Palos Verdes Peninsula, California, and within Santa Barbara Channel, California, Commencement Bay, Washington, Resurrection Bay, Alaska, and Port Valdez, Alaska. For two of these failures, ages were determined by identifying acoustic reflectors in the vicinity of the failed masses that either clearly postdate or predate the landslide events. The ages of the reflectors are determined by tracing them to the locations of nearby ODP borings or to piston cores dated using radiocarbon methods. Three of the landslides produced tsunamis during historic time (post 1750 AD) so the ages are well constrained. High-resolution subbottom reflection profiles also allow us to estimate the dimensions of the failed masses. Although the examples selected clearly do not represent all scales of tsunamigenic west coast landslides, this information is useful in providing input to statistically based models of landslide-induced tsunamis.
DE: 5754 Physical properties of materials
DE: 4564 Tsunamis and storm surges
DE: 3022 Marine sediments--processes and transport
DE: 3045 Seafloor morphology and bottom photography
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting