Brewer, P.G., C. Paull, E.T. Peltzer, W. Ussler, G. Rehder1 and G. Friederich
Monterey Bay Aquarium Research Institute
7700 Sandholdt Road
Moss Landing, California 95039-9644 USA.
1: Now at GEOMAR Center for Marine Research, Kiel, Germany.
Geophysical Research Letters (2002) 29 doi:10.1029/2002GL014727.
Received: 2002 January 14.
Accepted: 2002 June 6.
Published: 2002 November 30.
We report on controlled experiments to document the fate of naturally occurring methane hydrate released from the sea floor (780 m, 4.3°C) by remotely operated vehicle (ROV) disturbance. Images of buoyant sediment-coated solids rising (~0.24 m/s) from the debris cloud, soon revealed clear crystals of methane hydrate as surficial material sloughed off. Decomposition and visible degassing began close to the predicted phase boundary, yet pieces initially of ~0.10 m size easily survived transit to the surface ocean. Smaller pieces dissolved or dissociated before reaching the surface ocean, yet effectively transferred gas to depths where atmospheric ventilation times are short relative to methane oxidation rates.
© 2002 by the American Geophysical Union.
We thank the pilots of the ROV Tiburon, and the captain and crew of the RV Western Flyer for their skilled assistance. Funding for this project was provided to MBARI by the David and Lucile Packard Foundation.