HR: 1340h
AN: S23A-1115    [Abstracts]
TI: Seafloor and Shallow Sub-surface Acoustic Properties Studies: a Geophysical Baseline for the Fluid-Mud MURI Site
AU: * Orange, A
EM: aorange1@compuserve.com
AF: Marine Geosciences Division, AOA Geophysics Inc, 7532 Sandholdt Road,Suite 6, Moss Landing, CA 95039, United States
AU: Garcia-Garcia, A
EM: agarcia@pmc.ucsc.edu
AF: Marine Geosciences Division, AOA Geophysics Inc, 7532 Sandholdt Road,Suite 6, Moss Landing, CA 95039, United States
AU: Garcia-Garcia, A
EM: agarcia@pmc.ucsc.edu
AF: Earth and Planetary Sciences Department, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, United States
AU: Ramirez, T
EM: tony_ramirez@aoageophysics.com
AF: Marine Geosciences Division, AOA Geophysics Inc, 7532 Sandholdt Road,Suite 6, Moss Landing, CA 95039, United States
AU: Henderson, J
EM: jennifer_henderson@aoageophysics.com
AF: Marine Geosciences Division, AOA Geophysics Inc, 7532 Sandholdt Road,Suite 6, Moss Landing, CA 95039, United States
AU: Orange, D
EM: dorange@blackgoldenergy.com
AF: Earth and Planetary Sciences Department, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, United States
AU: Orange, D
EM: dorange@blackgoldenergy.com
AF: Black Gold Energy LLC, Jalan Kemang, Timur 22, Plaza City View, Jakarta, 12510, Indonesia
AU: Levey, M
EM: matt_levey@aoageophysics.com
AF: Marine Geosciences Division, AOA Geophysics Inc, 7532 Sandholdt Road,Suite 6, Moss Landing, CA 95039, United States
AU: Henning, A
EM: alison.henning@aoageophysics.com
AF: AOA Geophysics Inc, 2500 Tanglewilde Ave., Suite 120, Houston, TX 770063, United States
AU: party field, R
AB: During June 2007 and in relatively benign summer conditions, high-resolution multibeam (bathymetry and backscatter), sidescan sonar, and sub-bottom profiling datasets were acquired off the coast of Louisiana, west of Atchafalaya Bay, where the multi-year research program "Mechanism of Fluid-Mud Interactions Under Waves" (MURI) is focused. This survey was the first of two field programs separated by several months designed to evaluate variations in seafloor and shallow sub-surface acoustic properties at three sites in the northern Gulf of Mexico. In addition to temporal (seasonal) and spatial variations, we are examining the differences in acoustic signature of the seafloor at different frequencies. The surveyed area covered an area of 12 kilometers2 in shallow water (5-26 meters) plus two 54-kilometers long transects perpendicular to the coastline. They were chosen as being a baseline for further studies for MURI- related scientists (e.g., giving information about the sediment properties where WHOI sensors are deployed). The resultant multibeam bathymetry was gridded using a weighted uncertainty method at 0.5 meters and the multibeam backscatter amplitude gridded at 0.25 meters. All the data were tide and SVP corrected. A preliminary analysis of high resolution bathymetric data shows detailed natural and man-made features on the present seafloor. The sub-bottom data shows up to 20 meters of sedimentary layers and several infilled channels topped by a strong unconformity. A follow-up cruise in the upcoming winter "08 will survey the same sites with the same systems, using the same boat, to determine whether there are any seasonal variations in the datasets.
DE: 3002 Continental shelf and slope processes (4219)
DE: 3020 Littoral processes
DE: 3022 Marine sediments: processes and transport
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 4259 Ocean acoustics
SC: Seismology [S]
MN: 2007 Fall Meeting