Minimum distribution of subsea ice-bearing permafrost on the U.S. Beaufort Sea continental shelf

摘要: [1] 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 formerly subaerial permafrost probable dissociation associated gas hydrates. Relict has never been systematically mapped along 700-km-long U.S. Beaufort Sea shelf is often assumed extend ∼120 m water depth, approximate amount since Pleistocene. Here, 5,000 km multichannel seismic (MCS) data acquired between 1977 1992 were examined for high-velocity (>2.3 km s−1) refractions consistent with ice-bearing, coarse-grained sediments. Permafrost identified <5% tracklines at depths ∼5 470 m below seafloor. The resulting map reveals minimum extent subsea ice-bearing permafrost, which does not seaward 30 km offshore or beyond 20 m isobath.