An experiment demonstrating that marine slumping is a mechanism
to transfer methane from seafloor gas-hydrate deposits
into the upper ocean and atmosphere

C. K. Paull,1 P. G. Brewer,1 W. Ussler III,1 E. T. Peltzer,1 G. Rehder2 and D. Clague1
1: Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, California 95039, USA
2: GEOMAR, 24148 Kiel, Germany.

Geo-Marine Letters (2002) DOI: 10.1007/s00367-002-0113-y.

Received: 2002 June 13.
Accepted: 2002 September 27.
Published online: 2002 November 13.


ABSTRACT

The scientific community is engaged in a lively debate over whether and how venting from the gas-hydrate reservoir and the Earth's climate is connected. The various scenarios which have been proposed are based on the following assumptions: the inventory of methane gas-hydrate deposits is locally enormous, the stability of marine gas-hydrate deposits can easily be perturbed by temperature and pressure changes, enough methane can be released from these deposits to contribute adequate volumes of this isotopically distinct greenhouse gas to alter the composition of oceanic or atmospheric methane reservoirs, and the mechanisms exist for the transfer of methane from deeper geologic reservoirs to the ocean and/or atmosphere. However, some potential transfer mechanisms have been difficult to evaluate. Here, we consider the possibility of marine slumping as a mechanism to transfer methane carbon from gas hydrates within the seafloor into the ocean and atmosphere. Our analyses and field experiments indicate that large slumps could release volumetrically significant quantities of solid gas hydrates which would float upwards in the water column. Large pieces of gas hydrate would reach the upper layers of the ocean before decomposing, and some of the methane would be directly injected into the atmosphere.

© 2002 by Springer-Verlag.


Acknowledgements

Support for this work was provided from the David and Lucile Packard Foundation.


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