Escape of methane gas from the seabed along the West Spitsbergen continental margin
Graham K. Westbrook, Kate E. Thatcher (School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, U.K.), Eelco J. Rohling (National Oceanography Centre Southampton, University of Southampton, Southampton, U.K.), Alexander M. Piotrowski (Godwin Laboratory for Palaeoclimate Research, Department of Earth Sciences, Cambridge University, Cambridge, U.K.), Heiko Pälike (National Oceanography Centre Southampton, University of Southampton, Southampton, U.K.), Anne H. Osborne (Bristol Isotope Group, Department of Earth Sciences, University of Bristol, Bristol, U.K.), Euan G. Nisbet (Department of Earth Sciences, Royal Holloway University of London, Egham, U.K.), Tim A. Minshull (National Oceanography Centre Southampton, University of Southampton, Southampton, U.K.), Mathias Lanoisellé (Department of Earth Sciences, Royal Holloway University of London, Egham, U.K.), Rachael H. James, Veit Hühnerbach, Darryl Green (National Oceanography Centre Southampton, University of Southampton, Southampton, U.K.), Rebecca E. Fisher (Department of Earth Sciences, Royal Holloway University of London, Egham, U.K.), Anya J. Crocker, Anne Chabert, Clara Bolton (National Oceanography Centre Southampton, University of Southampton, Southampton, U.K.), Agnieszka Beszczynska-Möller (Climate Sciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany), Christian Berndt (National Oceanography Centre Southampton, University of Southampton, Southampton, U.K.; Leibniz Institute of Marine Sciences at University of Kiel (IFM-GEOMAR), Kiel, Germany), and Alfred Aquilina (Organic Geochemistry Unit, Bristol Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Bristol, U.K.)
Abstract
More than 250 plumes of gas bubbles have been discovered emanating from the seabed of the West Spitsbergen continental margin, in a depth range of 150–400 m, at and above the present upper limit of the gas hydrate stability zone (GHSZ). Some of the plumes extend upward to within 50 m of the sea surface. The gas is predominantly methane. Warming of the northward-flowing West Spitsbergen current by 1 °C over the last thirty years is likely to have increased the release of methane from the seabed by reducing the extent of the GHSZ, causing the liberation of methane from decomposing hydrate. If this process becomes widespread along Arctic continental margins, tens of Teragrams of methane per year could be released into the ocean.
(Received 20 May 2009, accepted 30 June 2009, published 6 August 2009.)
Citation: (2009), Escape of methane gas from the seabed along the West Spitsbergen continental margin, Geophys. Res. Lett., 36, L15608, doi:10.1029/2009GL039191.
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