HR: 1340h
AN: S23A-1114    [Abstracts]
TI: Seafloor Acoustic Properties Studies: Panama City, Florida
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: * Garcia-Garcia, A
EM: agarcia@pmc.ucsc.edu
AF: Marine Geoscience Division, AOA Geophysics Inc, 7532 Sandholdt Road, Suite 6, Moss Landing, CA 95039, United States
AU: Mulrey, M
EM: mkm@aoageophysics.com
AF: AOA Geophysics Inc, 5828 Balcones Drive, Suite 204, Austin, TX 78731, 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: Shipton, G
EM: geoff@tritonimaginginc.com
AF: Triton Imaging Inc, 125 Westridge Drive, Watsonville, CA 95076, United States
AU: field party, R
AB: In 2007 we carried out the first of two field programs designed to evaluate variations in seafloor and shallow sub- surface acoustic properties at three sites in the northern Gulf of Mexico. This two-year program includes the acquisition, processing, and interpretation of high-resolution geophysical data including multibeam bathymetry, multibeam backscatter, side scan sonar, and sub-bottom profiling. In addition to temporal (seasonal) and spatial variations, we are examining the differences in acoustic signature of the seafloor at different frequencies. During June 2007 and in relatively benign summer conditions, high-resolution multibeam (bathymetry and backscatter) and sidescan sonar datasets were acquired off Panama City, Florida, using the R/V "Pelican". A challenging mobilization included mounting the Kongsberg Simrad EM3002 (300 kHz) and EM1002 (100 kHz) to the vessel. Side-scan sonar datasets were acquired with a dual frequency Benthos SIS-1000 working at 90-110 kHz. Each of the surveyed areas were 2km x 2km (approx.) and were chosen as potential sites of varying acoustic properties both outside and inside St. Andrews Bay. Three areas were surveyed inside the bay (BMHdavis, BMHvehicle, BMHmud) and two were surveyed outside the bay (Area14 and Area8). The resultant multibeam bathymetry was gridded using a weighted uncertainty method at .5 meters and the multibeam backscatter amplitude gridded at .25 meters. All the data were tide and SVP corrected. The preliminary analyses indicate spatial acoustic differences between the sites. Within individual sites there are differences in the data as a function of the frequencies used to map the seafloor. 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 as well.
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