Mississippi Canyon 118 Gas Hydrate Study

Sponsor: National Institute for Undersea Science and Technology, via the University of Mississippi

Roger Sassen and Ph.D. student Woodong Jung are studying one of the most important new hydrate sites in the east-central Gulf of Mexico. The MC 11 8 gas hydrate site was discovered by Harry Roberts and Roger Sassen in 2002 and became of great interest to others at the site of a new seafloor observatory. The Mississippi Canyon (MC) 118 site is an isolated sheet of carbo nate rock at ~890 meters water depth that formed from microbial oxidation of venting hydrocarbons over a long period of time. The site contains gas vents, structure II gas hydrate, and chemosynthetic communities that are under active study. GERG is working with t he University of Mississippi with funding from the National Institute for Undersea Technology and Science (NIUST) to better understand the gas hydrate system and geologic complexity of the MC 118 site. A consortium of universities is planning a deep-sea observatory at the site to monitor the process of geologic change at the complex site. Sassen recently presented a paper on the si te at a dedicated session of the Offshore Technology Conference and is scheduled to dive on the site in the Johnson Sea Link research submersible in September.

 High-resolution sonar data shows the site is about 1,100 meters across with strongly irregular seafloor from carbonate rock that contrasts strongly with the otherwise flat and featureless seafloor that extends for tens of kilome ters in all directions. Active gas vents with hydrate appear as crater-like features in high-resolution seismic. The processed image of the seafloor is courtesy of the University of Mississippi.