Summary for Field Activity Number 2010-012-FA

Area of Operations: Gulf of Mexico, North America, North Atlantic

Dates: Mar 01, 2010 to Mar 17, 2010

Objectives: High-resolution seismic, swath bathymetry, and sidescan sonar mapping of the inner shelf off the Mississippi Barrier islands to map the geologic framework and assess the extent of offshore sand deposits.

Type of Activity: Sea floor mapping

Information to be derived: Sea floor map
Bathymetric maps
Morphology
Stratigraphy

Summary: A cruise aboard the R/V Tommy Munro was conducted March 1-17, 2010 by the Woods Hole Science Center. The purpose of the cruise was to collect swath bathymetry, sidescan sonar imagery and high-resolution chirp seismic profiles to define the sea floor morphology and the shallow stratigraphy of the inner shelf offshore of a string of barrier islands in the northern Gulf of Mexico along the Mississippi coast. The scientific goals of the project were twofold: 1) to better understand the geologic evolution of this coastal region, and 2) to provide stratigraphic information to the U.S. Army Corps of Engineers for an assessment of sand resources that they are compiling for the region. The cruise was hampered by less-than-ideal weather conditions. Data were collected during the following days: 3-9 March, 11-12 March, 14-16 March. During the cruise seismic data were collected along 1778 km of survey tracklines, swath bathymetry along 1418 km of survey tracklines, and sidescan imagery along 1332 km of survey tracklines. Preliminary processing was completed in the field on all three data types. The quality of the chirp and bathymetry data was excellent. During the initial part of the cruise, the sidescan imagery was of inferior quality because of ship noise. The location of the sidescan vehicle was moved from the port side to the stern of the ship during the first port call, and the quality improved significantly. For the lower quality imagery, processing procedures were modified to minimize the ship noise.

USGS Project Number: 2921-E3SWH - Project Description

Contact: Dave Twichell (dtwichell@usgs.gov)