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USGS and WHOI Investigate Gas-Hydrate Mounds on the Gulf of Mexico Sea Floor
In mid-June 2004, researchers from the Woods Hole Oceanographic Institution (WHOI) and the U.S. Geological Survey (USGS) participated in a 5-day cruise aboard the research vessel Pelican to investigate gas-hydrate mounds in the northern Gulf of Mexico. This cruise was one of several site-survey cruises characterizing the sea floor before shallow drilling that is anticipated in spring 2005. The purpose of the recent cruise was to collect electrical and photographic data that complement and augment existing multichannel-seismic, vertical-array-seismic, geochemical, and thermal data sets. USGS and WHOI are just two of the many institutions involved in this joint venture of Federal, academic, and industry groups collaborating on drilling gas hydrates in the Gulf of Mexico. The Joint Industry Program (JIP) intends to assess the hazards associated with drilling in sediment containing gas hydrate, and the two mounds in Mississippi Canyon visited during the Pelican cruise are potential JIP drillsites. Gas-hydrate mounds are well documented in shallower waters of the Gulf of Mexico, and many mounds host chemosynthetic communities. The two mounds visited during this cruise are in water about 1,300 m deep. The mounds revealed varying electrical conductivities, some chemosynthetic communities, white masses on the sea floor that might be hydrate or carbonate, and various fish, crabs, and other animals. This cruise was the first to use WHOI's high-resolution digital tow camera in the Gulf of Mexico, and also the first test cruise for the bottom-towed electromagnetic streamer. Both instruments functioned flawlessly. The bottom photographs have been linked with navigation data in a geographic information system (GIS) and will ultimately be put in a mosaic, providing a comprehensive visualization of sea-floor features in this particular area of the Gulf of Mexico. The electrical measurements will provide new hydrate- and salinity-distribution information to augment previously collected data sets in the Atwater Valley region. Scientific crew members on board included WHOI scientists Rob Evans (Chief Scientist) and Dan Fornari, with additional support from Marshall Swartz and Alan Gardner. A navigation team from the USGS office in Menlo Park, CA, was led by Mike Boyle and Jennifer Dougherty, and John Evans and Lauren Gilbert from the USGS Woods Hole Science Center provided GIS and navigation support. The cruise was a scientific and culinary success. The data collection benefited from calm seas and perfect weather, and the cuisine benefited from a sizable mahi mahi hooked on the final day of research. Even with a menu featuring made-to-order eggs and crème brûlé, no reward is greater than fresh fish after a long day of data collection at sea!
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in this issue:
Gas-Hydrate Mounds Cruise to California Seamounts
Scientists Interviewed for Documentary The National Map Comes to Florida
Geologist Joins USGS in St. Petersburg |
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