Interactions Between Fluid Flow, Geochemistry, and Biogeochemical Processes at Methane Seeps

Abstract

Since their first discovery 20 years ago, numerous cold seeps have been found, mainly along active and passive continental margins. Methane gas plays a key role in the global car-bon cycle and, as a highly potent greenhouse gas, in the control of the Earth's climate. In diffusion-controlled sediments, methane is completely oxidized within the sediment col-umn and does not reach the overlying water. In contrast, at cold seeps, methane is trans-ported to the sediment surface by advective forces. For geologic reasons, fluid advection and the respective methane flux are spatially and temporarily variable. Microbial commu-nities of methane-oxidizing archaea in syntrophy with sulfate-reducing bact..