Archive of Raw Bottom Photographs Collected During Cruise P1-04-GM, Northern Gulf of Mexico, 21-24 June, 2004
USGS Open-File Report 2004-1285
This report is the raw data archive for bottom photographs and related tow-camera data collected in June, 2004, in the northern Gulf of Mexico aboard the research vessel R/V Pelican. The photographic images were collected to evaluate whether chemosynthetic organisms existed on the sea floor in association with two sea-floor mud mounds in 1,300-m water depth on the floor of the Mississippi Canyon near lease block Atwater Valley 14 (Figure 1). These mounds were identified as a potential drilling site for a joint industry-government-academia project in the Gulf of Mexico to study gas hydrate (Jones and others, 2004). Similar to many other mounds in the northern Gulf of Mexico (Sager and others, 2004), these mounds show seismic amplitude bright spots and are probable sites of fluid venting, providing a potentially favorable environment for development of chemosynthetic communities and surficial gas hydrate. Because drilling is not allowed within approximately 300 m of chemosynthetic communities without waivers from the Minerals Management Service (MMS), understanding the distribution of seafloor ecosystems is therefore a necessary part of safety and permitting.
This cruise is known by the designations PE-04-49 (UNOLS), P1-04-GM (USGS InfoBank), and 04021 (USGS Woods Hole Science Center Field Activity Number). The tow camera was deployed 5 times around and between two mud mounds (Figure 2) resulting in 5,973 photographs. Tow 1 was a test tow to determine water clarity and optimal towing height, and did not include all supporting measurements (e.g., layback). Tow 3 was aborted shortly after deployment and provided no useful imagery. This archive therefore contains raw imagery from tow 1 and tow 2 (disk 1) and tows 4 and 5 (disk 2). Interpretations are not part of this report. Subsequent publications are expected to give corrected navigation, image dimensions, interpretations, and other processing improvements for the digital imagery.
Funding in support of this cruise was provided by the Department of Energy, the Deep Ocean Exploration Institute of the Woods Hole Oceanographic Institution, and USGS. We thank Elizabeth Pendleton and Dann Blackwood for their thorough reviews, and Donna Newman for her patience and expertise in formatting this publication.
Equipment and Ship
The R/V Pelican is a 35-m-long research vessel operated by the Louisiana Universities Marine CONsortium (LUMCON) out of Cocodrie, LA. It can accommodate a research staff of up to 16, has several labs on board, and a good working deck for equipment deployment and recovery. (Figure 3).
The digital camera is a Nikon 995 Coolpix, 3.3 Mpixel, which records up to 1000 images of 2048x1536 resolution on a 1 GB CompactFlash card. It is part of the WHOI Deep Submergence Towed Digital Camera and MultiRock Coring System (TowCam). The towing sled was built specifically for this cruise on the Pelican (Figures 4-7) and houses the digital camera, a SeaBird25 ctd profiler (including altimeter, depth, conductivity, temperature, and turbidity sensors), strobe lights, and batteries to operate the camera (Figure 8). As configured, this system does not provide the MultiRock Coring System capability. The system utilizes standard UNOLS 0.322" coaxial CTD sea cable for towing from the ship, allowing for real-time monitoring of digital and altitude (and other SeaBird) data for maintaining the camera sled at a uniform height above the sea floor. A more complete description of the camera and system is included in the file towcam_manual.pdf.
The two DVDs comprising this publication contain files with the raw imagery and supporting data. All supporting data are included on each DVD. The DVDs differ in the included raw imagery; the first DVD has the imagery from tows 1 and 2; the second DVD contains the raw imagery from tows 4 and 5. There were no useful images from tow 3, which was aborted early.
Jones, E., 2004, Results of the 2004 Chevron Texaco and others, Gulf of Mexico Gas Hydrate Research Coring Project (abs.), in Collett, T.S., and Johnson, A., Natural Gas Hydrates; Energy Resource Potential and Associated Geologic Hazards: AAPG Hedberg Research Conference. http://www.searchanddiscovery.com/documents/abstracts/2004hedberg_vancouver/short/jones.htm
Sager, W.W., MacDonald, I.R., and Hou, R., 2004, Side-scan sonar imaging of hydrocarbon seeps on the Louisiana continental slope: American Association of Petroleum Geologists Bulletin, v. 88, no. 6, p. 725-746.
This DVD-ROM has been produced in accordance with the ISO 9660 Standard and is therefore capable of being read on any computing platform that has appropriate DVD-ROM driver software installed.
The photographs are stored in JPEG format and can therefore be viewed with any number of common image manipulation programs.
This DVD-ROM publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
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