FN Archimer Export Format
PT J
TI Methane discharge from a deep-sea submarine mud volcano into the upper water column by gas hydrate-coated methane bubbles
BT 
AF SAUTER, Eberhard
   MUYAKSHIN, Sergey
   CHARLOU, Jean-Luc
   SCHLUTER, Michael
   BOETIUS, Antje
   JEROSCH, Kerstin
   DAMM, Ellen
   FOUCHER, Jean-Paul
   KLAGES, Michael
AS 1:1;2:2;3:3;4:1;5:4;6:1;7:1;8:3;9:1;
FF 1:;2:;3:PDG-DOP-DCB-GM-LGM;4:;5:;6:;7:;8:PDG-DOP-DCB-GM-LGG;9:;
C1 Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany.
   Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603950, Russia.
   IFREMER, Ctr Brest, DRO, GM,Dept Marine Geosci, F-29280 Plouzane, France.
   Max Planck Inst Marine Microbiol, D-28359 Bremen, Germany.
C2 INST A WEGENER, GERMANY
   RUSSIAN ACAD SCI, RUSSIA
   IFREMER, FRANCE
   INST MAX PLANCK (MARINE MICROBIOL), GERMANY
SI BREST
SE PDG-DOP-DCB-GM-LGM
   PDG-DOP-DCB-GM-LGG
IN WOS Ifremer jusqu'en 2018
   copubli-europe
   copubli-int-hors-europe
IF 3.887
TC 224
UR https://archimer.ifremer.fr/doc/2006/publication-1345.pdf
LA English
DT Article
DE ;Hydro acoustics;Gas hydrates;Gas bubbles;Submarine mud volcanoes;Methane budget;Plume;Methane sources
AB The assessment of climate change factors includes a constraint of methane sources and sinks. Although marine geological Sources are recognized as significant, unfortunately, most submarine sources remain poorly quantified. Beside cold vents and coastal anoxic sediments, the large number of submarine mud volcanoes (SMV) may contribute significantly to the oceanic methane pool. Recent research suggests that methane primarily released diff-usively from deep-sea SMVs is immediately oxidized and, thus, has little climatic impact.   New hydro-acoustic, Visual, and geochemical observations performed at the deep-sea mud volcano Hakon Mosby reveal the discharge of gas hydrate-coated methane bubbles and gas hydrate flakes forming huge methane plumes extending from the seabed in 1250 m depth up to 750 in high into the water column. This depth coincides with the upper limit of the temperature-pressure field of gas hydrate stability. Hydrographic evidence suggests bubble-induced upwelling within the plume and extending above the hydrate stability zone. Thus, we propose that a significant portion of the methane from discharged methane bubbles can reach the upper water column, which may be explained due to the formation of hydrate skins. As the water mass of the plume rises to shallow water depths, methane dissolved from hydrated bubbles may be transported towards the surface and released to the atmosphere. Repeated acoustic surveys performed in 2002 and 2003 suggest continuous methane emission to the ocean. From seafloor visual observations we estimated a gas flux of 0.2 (0.08-0.36) mol s(-1) which translates to several hundred tons yr(-1) under the assumption of a steady discharge. Besides, methane was observed to be released by diffusion from sediments as well as by focused outflow of methane-rich water. In contrast to the bubble discharge, emission rates of these two pathways are estimated to be in the range of several tons yr(-1) and, thus, to be of minor importance.   Very low water column methane oxidation rates derived from incubation experiments with tritiated methane suggest that methane is distributed by currents rather than oxidized rapidly. 
PY 2006
PD MAR
SO Earth and Planetary Science Letters
SN 0012-821X
PU Elsevier
VL 243
IS 3-4
UT 000236600600004
BP 354
EP 365
DI 10.1016/j.epsl.2006.01.041
ID 1345
ER

EF