HR: 11:15h
AN: U52A-04    [Abstracts]
TI: Analysis of Satellite Time-lapse and Sunglint Imagery of Tsunami Waves from the 26 December 2004 Great Sumatra-Andaman Islands Earthquake
AU: * Garay, M J
EM: garay@atmos.ucla.edu
AF: University of California, Los Angeles, Box 951565 7127 Math Sciences Building, Los Angeles, CA 90095 United States
AU: Diner, D J
EM: David.J.Diner@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Titov, V
EM: vasily.titov@noaa.gov
AF: NOAA Pacific Marine Environmental Laboratory/University of Washington JISAO, 7600 Sand Point Way NE Building 3, Seattle, WA 98115 United States
AU: Hall, J R
EM: Jeffrey.R.Hall@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: DeJong, E M
EM: Eric.M.DeJong@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Averill, C
EM: caverill@sdsio.jpl.nasa.gov
AF: Raytheon Information Technology and Scientific Services, 299 N. Euclid Ave., Suite 500, Pasadena, CA 91101 United States
AB: The magnitude 9.0 earthquake which occurred off the west coast of Sumatra, Indonesia at 00:58:53 UTC on 26 December 2004 triggered a major tsunami, which caused catastrophic devastation and loss of life in the Indian Ocean region. The leading tsunami wave moved through the waters of the Indian Ocean at approximately 750 km per hour, reaching the eastern coast of India around 3:35 UTC, based on tide gauge measurements at the Indian port of Visakhapatnam. It is well known, however, that tsunamis occur as a series of large waves that continue to arrive some time after the initial wave, often causing significant additional destruction. Between 5:10 and 5:20 UTC the Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite detected wave activity near the eastern Indian and western Sri Lankan coasts. Because MISR's nine cameras observe any given region over a period of approximately 7 minutes, the instrument was able to capture unique time-lapse, animated imagery of extremely large waves breaking at various points along the Indian coast, including "edge waves" moving parallel to the shoreline. These data provide quantitative information on the location and timing of the breaking waves, along with estimates of speed (45 kph onshore), orientation, crest-to-crest wavelength (9 km), and frequency (12 minutes between waves). In addition, by looking at specific view angles strongly influenced by sunglint, MISR detects changes in sea surface slope. The latter technique resulted in the unexpected detection of deep ocean wave features about 30-40 km from Sri Lanka's southwestern coast, in a pattern highly correlated with the location of the continental shelf. In conjunction with bathymetric measurements of ocean depth, the information provided by MISR will be used to refine and calibrate tsunami propagation models. Improving these models has two primary benefits. First, a detailed understanding of wave interactions with coastal areas is necessary for understanding tsunami wave inundation and for developing damage mitigation approaches. Second, increased predictive capability will make possible more accurate near-real-time forecasts of tsunami arrival times and effects.
DE: 4275 Remote sensing and electromagnetic processes (0689)
DE: 4560 Surface waves and tides (1255)
DE: 4564 Tsunamis and storm surges
SC: Union [U]
MN: 2005 Joint Assembly