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Origin of pingo‐like features on the Beaufort Sea shelf and their possible relationship to decomposing methane gas hydrates
Author(s) -
Paull Charles K.,
Ussler William,
Dallimore Scott R.,
Blasco Steve M.,
Lorenson Thomas D.,
Melling Humfrey,
Medioli Barbara E.,
Nixon F. Mark,
McLaughlin Fiona A.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl027977
Subject(s) - clathrate hydrate , permafrost , methane , geology , beaufort sea , arctic , oceanography , submarine pipeline , continental shelf , seafloor spreading , sediment , hydrate , environmental science , geomorphology , ecology , chemistry , organic chemistry , biology
The Arctic shelf is currently undergoing dramatic thermal changes caused by the continued warming associated with Holocene sea level rise. During this transgression, comparatively warm waters have flooded over cold permafrost areas of the Arctic Shelf. A thermal pulse of more than 10°C is still propagating down into the submerged sediment and may be decomposing gas hydrate as well as permafrost. A search for gas venting on the Arctic seafloor focused on pingo‐like‐features (PLFs) on the Beaufort Sea Shelf because they may be a direct consequence of gas hydrate decomposition at depth. Vibracores collected from eight PLFs had systematically elevated methane concentrations. ROV observations revealed streams of methane‐rich gas bubbles coming from the crests of PLFs. We offer a scenario of how PLFs may be growing offshore as a result of gas pressure associated with gas hydrate decomposition.