OS33A-1994
Anaerobic oxidation of methane related to methane seepage along the northern US Atlantic margin
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Tina Treude1, Stefan Krause2, Frederick S Colwell3, Michael Franklin Graw4, John Pohlman5 and Carolyn D Ruppel5, (1)University of California Los Angeles, Los Angeles, CA, United States, (2)GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, (3)Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, OR, United States, (4)Oregon State University, College of Earth, Ocean, and Atmospheric Science, Corvallis, OR, United States, (5)USGS Coastal and Marine Science Center Woods Hole, Woods Hole, MA, United States
Abstract:
Microbial anaerobic oxidation of methane (AOM), coupled to sulfate reduction, is an important mechanism in marine sediments for reducing methane emissions into the atmosphere. Here we report on AOM and sulfate reduction activity determined from sediments collected at recently-discovered methane seeps along the northern US Atlantic margin (USAM), where more than 550 gas plumes rise from the seafloor. Many of these gas plumes lie within or above the upper limit of gas hydrate stability on the continental slope. Samples were taken by TV-multicorer and a piston corer aboard the R/V Sharp during a September 2015 expedition that was jointly organized by the US Geological Survey, the Oregon State University, GEOMAR, and UCLA. This presentation will display preliminary data of AOM activity from selected seeps at the USAM to discuss (1) the capacity of the methane biofilter in relation to well-known seep sites, (2) its influence on geochemistry (e.g., sulfide accumulation, carbonate formation) and biology (established chemosynthetic communities), and (3) its potential response to recent methane mobilization from dissociating gas hydrates.
