Temporal Constraints on Hydrate-Controlled Methane Seepage off Svalbard

• Published in: Science (American Association for the Advancement of Science) Vol. 343; no. 6168; pp. 284 - 287
• Main Authors: Berndt, C., Feseker, T., Treude, T., Krastel, S., Liebetrau, V., Niemann, H., Bertics, V. J., Dumke, I., Dünnbier, K., Ferré, B., Graves, C., Gross, F., Hissmann, K., Hühnerbach, V., Krause, S., Lieser, K., Schauer, J., Steinle, L.
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 17-01-2014; The American Association for the Advancement of Science
• Subjects: Arctic Regions; Carbonates; Geofag: 450; Geosciences: 450; Global warming; Greenhouse Effect; Hydrates; Hydrocarbon leakage & seepage; Matematikk og Naturvitenskap: 400; Mathematics and natural science: 400; Methane; Methane - chemistry; Norway; Observatories; Ocean floor; Oceans; Oceans and Seas; Seasons; Sediments; Temperature; VDP; Water depth; Water temperature; Arctic Regions; Norway; Svalbard Islands
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1246298

Methane hydrate is an icelike substance that is stable at high pressure and low temperature in continental margin sediments. Since the discovery of a large number of gas flares at the landward termination of the gas hydrate stability zone off Svalbard, there has been concern that warming bottom waters have started to dissociate large amounts of gas hydrate and that the resulting methane release may possibly accelerate global warming. Here, we corroborate that hydrates play a role in the observed seepage of gas, but we present evidence that seepage off Svalbard has been ongoing for at least 3000 years and that seasonal fluctuations of 1° to 2°C in the bottom-water temperature cause periodic gas hydrate formation and dissociation, which focus seepage at the observed sites.