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Influence of permafrost thaw on an extreme geologic methane seep
Author(s) -
Sullivan Taylor D.,
Parsekian Andrew D.,
Sharp Janelle,
Hanke Philip J.,
Thalasso Frederic,
Shapley Mark,
Engram Melanie,
Walter Anthony Katey
Publication year - 2021
Publication title -
permafrost and periglacial processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.867
H-Index - 76
eISSN - 1099-1530
pISSN - 1045-6740
DOI - 10.1002/ppp.2114
Subject(s) - permafrost , petroleum seep , methane , geology , thermokarst , arctic , sediment , earth science , cold seep , coring , clathrate hydrate , bathymetry , hydrology (agriculture) , oceanography , geomorphology , drilling , ecology , mechanical engineering , chemistry , organic chemistry , hydrate , engineering , geotechnical engineering , biology
The occurrence and magnitude of natural fossil methane (CH 4 ) emissions in the Arctic are poorly known. Emission of geologic CH 4 , a potent greenhouse gas, originating beneath permafrost is of particular interest due to the potential for positive feedback to climate warming, whereby accelerated permafrost thaw releases permafrost‐trapped CH 4 in a future warmer climate. The development of through‐going taliks in Arctic lakes overlying hydrocarbon reservoirs is one mechanism of releasing geologically sourced, subpermafrost CH 4 . Here we use novel gas flux measurements, geophysical observations of the subsurface, shallow sediment coring, high‐resolution bathymetry measurements, and lake water chemistry measurements to produce a synoptic survey of the gas vent system in Esieh Lake, a northwest Alaska lake with exceedingly large geologic CH 4 seep emissions. We find that microbially produced fossil CH 4 is being vented though a narrow thaw conduit below Esieh Lake through pockmarks on the lake bottom. This is one of the highest flux geologic CH 4 seep fields known in the terrestrial environment and potentially the highest flux single methane seep. The poleward retreat of continuous permafrost may have implications for more subcap CH 4 release with increased permafrost thaw.