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USGS Coastal and Marine Geology Program

Field Activity Details for field activity 2010-019-FA

Other ID: none

Status: Completed

Organization(s): USGS, St. Petersburg Coastal and Marine Science Center, USGS, Woods Hole Coastal and Marine Science Center

Funding Program(s):

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 Port/Location: Gulf Shores, AL

End Port/Location: Gulf Shores, AL

Start Date: 2010-07-16

End Date: 2010-07-23

Equipment Used: DGPS, Chirp 512i (sp)

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.


Affiliate Staff:

Notes: The GILBERT is now repaired and has left St. Pete. This should be the final change in schedule.


Mobile Bay AL

North: 30.68044 South: 30.22348 West: -87.7368 East: -88.1488


photo of G.K. Gilbert
G.K. Gilbert
photo of G.K. Gilbert
G.K. Gilbert


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:


Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
Chirp 512i (sp) --- Sub Bottom Profiler
DGPS --- Navigation

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