High Resolution Seismic Studies in the Laptev Sea Shelf: First Results and Future Needs

Modeling sub‐sea permafrost in the East Siberian Arctic Shelf: The Laptev Sea region

“…The values of λ f and C f used in this work are typical of ground materials with small porosity value η. We note that the values of λ f and C f are associated with silt/sandy silt (in the first layer) or sand/gravel (in the second layer) sediments found in the Laptev Sea at depths of 400 meters [ Kim et al , 1999]. The volumetric unfrozen liquid water content θ is typically higher for more finely grained materials [ Yershov , 1998], and qualitatively similar results(more significant thawing) can be expected in both considered cases.…”

“…We emphasize that the goal of this study is to update a model of salt-bearing permafrost degradation since the Holocene transgression in the Laptev Sea shelf. Uncertainties in the presented model lie in specifying the soil properties such as the thermal parameters C f and l f , the volumetric porosity h, and the salt content s. The values of l f and C f used in this work are typical of ground materials with small porosity value h. We note that the values of l f and C f are associated with silt/sandy silt (in the first layer) or sand/gravel (in the second layer) sediments found in the Laptev Sea at depths of 400 meters [Kim et al, 1999]. The volumetric unfrozen liquid water content q is typically higher for more finely grained materials [Yershov, 1998], and qualitatively similar results (more significant thawing) can be expected in both considered cases.…”

“…The state of permafrost in Arctic is a potential key to understanding whether and how methane, preserved in seabed reservoirs, can escape to the atmosphere. Unlike the terrestrial permafrost in the Arctic which experienced a change in its thermal regime caused by the 6–7°C mean annual air temperature increase since the last Glacial Maximum [ Frenzel et al , 1992], sub‐sea permafrost has been subjected to additional drastic transformations, e.g., inundation by the ocean, resulting in warming of the permafrost environment by as much as 17–20°C [ Soloviev et al , 1987; Kim et al , 1999; Romanovskii and Hubberten , 2001; Gavrilov and Tumskoy , 2003; Romanovskii et al , 2005].…”

“…We emphasize that because of the sparsely distributed measurements of the sub‐sea permafrost temperature, salinity, and distribution [ Ponomarev , 1940; Grigoriev , 1962; Molochushkin and Gavrilyev , 1970; Soloviev et al , 1987; Rachold et al , 2007], the present understanding of the current thermal state of sub‐marine permafrost in the Laptev Sea shelf is primarily based on modeling results [ Molochushkin and Gavrilyev , 1970; Danilov and Zhigarev , 1977; Soloviev et al , 1987; Fartyshev , 1993; Kim et al , 1999; Delisle , 2000; Romanovskii and Hubberten , 2001; Romanovskii et al , 2005]. These previously developed models significantly vary in the underlying assumptions, producing different results regarding the age, thickness and temperature of the sub‐sea permafrost.…”

Depositional history of the North Taymyr ice‐marginal zone, Siberia—a landsystem approach

“…It is enclosed to the west and east by bedrock hills 300-400 m high, dominated by flysch deposits (Neoproterozoic-Cambrian) and granitoids (Late Palaeozoic). The seas surrounding the peninsula (Kara and Laptev) are large, shallow shelf areas (<100 m deep) with a cover of partly permafrozen Quaternary sediments (Kim et al, 1999;Musatov, 1999;Kleiber et al, 2001).…”