Publikationsdatum:
2022-05-25
Beschreibung:
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.
Beschreibung:
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.
Beschreibung:
This research was sponsored by DOE-USGS
Interagency Agreement DE-FE0002911. L.B. was supported by a DOE
NETL/NRC Methane Hydrate Fellowship under DE-FC26-05NT42248.
Schlagwort(e):
Beaufort Sea
;
Climate change
;
Methane hydrates
;
Refraction
;
Sea level
;
Subsea permafrost
Repository-Name:
Woods Hole Open Access Server
Materialart:
Article
Format:
application/pdf
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