Other ID: none
Organization(s): USGS, St. Petersburg Coastal and Marine Science Center, USGS, Woods Hole Coastal and Marine Science Center
Location: Mobile Bay AL
Principal Investigator(s): David Twichell
Affiliate Investigator(s): Lisa Osterman, USGS-St. Pete; Chris Smith, USGS-St. Pete
Information Specialist(s): David Thompson, David Twichell
Data Type(s): Seismics: Sub Bottom Profiler, Location-Elevation: Navigation
Scientific Purpose/Goals: Conduct a reconnaissance mapping of the Holocene stratigraphy of Mobile Bay, AL to provide the framework for a coring program directed at reconstructing the recent history of the bay.
Start Date: 2010-07-16
Start Port/Location: Gulf Shores, AL
End Date: 2010-07-23
End Port/Location: Gulf Shores, AL
Equipment Used: Chirp 512i (sp), DGPS
Information to be Derived: High-resolution seismic profiling
Summary of Activity and Data Gathered: Five day-trips were completed aboard the R/V GILBERT in the southern half of Mobile Bay, AL to collect high-resolution seismic data to map the distribution and thickness of Holocene sediment that has accumulated in the bay. The EdgeTech 512i chirp sub-bottom system was used to acquire the data along tracklines spaced 1.5-7 km apart. The St. Pete group had just built a pontoon system for deploying their 512i (identical to the one the Woods Hole group uses), and this cruise was the first time it was used. The weather was excellent, and the BP oil spill had only a limited impact on our survey in the bay. Some of our lines near the mouth of the bay had to be shortened or shifted to avoid vessels associated with the oil spill cleanup.
Notes: The GILBERT is now repaired and has left St. Pete. This should be the final change in schedule.
Twichell, D., Kelso, K., and Pendleton, E., 2012, Evidence for Mid-Holocene Change in Depositional Style in Mobile Bay, Alabama: U.S. Geological Survey Open File Report 2012-1081, URL: http://pubs.usgs.gov/of/2012/1081/.