Friday, 31 August 2007
5.PS-146
Hydroacoustic Monitoring of the Bransfield Strait and Drake Passage, Antarctica: A first Analysis of Seafloor Seismicity, Cryogenic Acoustic Sources, and Cetacean Vocalizations
Robert P. Dziak1, Minkyu Park2, Haruyoshi Matsumoto1, Delwayne R. Bohnenstiehl3, Joseph H. Haxel1, David K. Mellinger1, Kathleen M. Stafford4, and Won Sang Lee2. (1) CIMRS, Oregon State University/NOAA, 2115 SE OSU Drive, HMSC, Newport, OR 97365, (2) Korea Ocean and Polar Research Institute, Inchon, South Korea, (3) Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, 2800 Faucette Drive, Jordan Hall, Raleigh, OR 27695, (4) Applied Physics Laboratory, University of Washington, Seattle, WA 98195
In November 2005, our research consortium deployed an Autonomous Underwater Hydrophone (AUH) array to begin long-term hydroacoustic monitoring of the waters in the Bransfield Strait and the Drake Passage. The array takes advantage of the efficient propagation of sound in the oceans to detect, locate and analyze the distribution of small to moderate-size earthquakes along the South Shetland Islands, Bransfield Strait , and Scotia Sea . All the hydrophones were recovered and redeployed in November of 2006, and we have now begun processing the 155GB of acoustic data. Preliminary review indicates the hydrophones recorded hundreds of earthquakes from the seafloor spreading centers and submarine volcanoes within the Bransfield Strait, as well as events from the subduction zone off the South Shetland Islands and from throughout the Scotia Sea. Moreover, we have observed harmonic tremor produced by the movement of large icebergs, and have detected the vocalizations of several critically endangered cetacean species.