Open AccessDetermining the flux of methane into H udson C anyon at the edge of methane clathrate hydrate stability
Author(s) -
Weinstein Alexander,
Navarrete Luis,
Ruppel Carolyn,
Weber Thomas C.,
Leonte Mihai,
Kellermann Matthias Y.,
Arrington Eleanor C.,
Valentine David L.,
Scranton Mary I.,
Kessler John D.
Publication year - 2016
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2016gc006421
Subject(s) - methane , clathrate hydrate , canyon , water column , geology , anaerobic oxidation of methane , thalweg , seawater , oceanography , hydrate , geomorphology , chemistry , sediment , organic chemistry
Methane seeps were investigated in Hudson Canyon, the largest shelf‐break canyon on the northern U.S. Atlantic Margin. The seeps investigated are located at or updip of the nominal limit of methane clathrate hydrate stability. The acoustic identification of bubble streams was used to guide water column sampling in a 32 km 2 region within the canyon's thalweg. By incorporating measurements of dissolved methane concentration with methane oxidation rates and current velocity into a steady state box model, the total emission of methane to the water column in this region was estimated to be 12 kmol methane per day (range: 6–24 kmol methane per day). These analyses suggest that the emitted methane is largely retained inside the canyon walls below 300 m water depth, and that it is aerobically oxidized to near completion within the larger extent of Hudson Canyon. Based on estimated methane emissions and measured oxidation rates, the oxidation of this methane to dissolved CO 2 is expected to have minimal influences on seawater pH.