Minimum distribution of subsea ice-bearing permafrost on the U.S. Beaufort Sea continental shelf
Brothers, Laura L.
Hart, Patrick E.
Ruppel, Carolyn D.
MetadataShow full item record
Starting in Late Pleistocene time (~19 ka), sea level rise inundated coastal zones worldwide. On some parts of the present-day circum-Arctic continental shelf, this led to flooding and thawing of formerly subaerial permafrost and probable dissociation of associated gas hydrates. Relict permafrost has never been systematically mapped along the 700-km-long U.S. Beaufort Sea continental shelf and is often assumed to extend to ~120 m water depth, the approximate amount of sea level rise since the Late Pleistocene. Here, 5,000 km of multichannel seismic (MCS) data acquired between 1977 and 1992 were examined for high-velocity (>2.3 km s−1) refractions consistent with ice-bearing, coarse-grained sediments. Permafrost refractions were identified along <5% of the tracklines at depths of ~5 to 470 m below the seafloor. The resulting map reveals the minimum extent of subsea ice-bearing permafrost, which does not extend seaward of 30 km offshore or beyond the 20 m isobath.
This paper is not subject to U.S. copyright. The definitive version was published in Geophysical Research Letters 39 (2012): L15501, doi:10.1029/2012GL052222.
Showing items related by title, author, creator and subject.
Bockheim, James G.; Kurz, Mark D.; Soule, Samuel A.; Burke, Andrea (2009-05)Nonsorted polygons with sand-filled wedges were investigated in lower and central Beacon Valley, Antarctica (77.82ºS, 160.67ºE) using field observations coupled with a 2-m resolution Digital Elevation Model and a ...
Isaksen, Ivar S. A.; Gauss, Michael; Myhre, Gunnar; Walter Anthony, Katey M.; Ruppel, Carolyn D. (American Geophysical Union, 2011-04-20)The magnitude and feedbacks of future methane release from the Arctic region are unknown. Despite limited documentation of potential future releases associated with thawing permafrost and degassing methane hydrates, the ...
Methane fluxes between terrestrial ecosystems and the atmosphere at northern high latitudes during the past century : a retrospective analysis with a process-based biogeochemistry model Zhuang, Qianlai; Melillo, Jerry M.; Kicklighter, David W.; Prinn, Ronald G.; McGuire, A. David; Steudler, Paul A.; Felzer, Benjamin S.; Hu, Shaomin (American Geophysical Union, 2008-08-18)We develop and use a new version of the Terrestrial Ecosystem Model (TEM) to study how rates of methane (CH4) emissions and consumption in high-latitude soils of the Northern Hemisphere have changed over the past century ...