Current rates and mechanisms of subsea permafrost degradation in the East Siberian Arctic Shelf

Natalia Shakhova; Igor Semiletov; Orjan Gustafsson; Valentin Sergienko; Leopold Lobkovsky; Oleg Dudarev; Vladimir Tumskoy; Michael Grigoriev; Alexey Mazurov; Anatoly Salyuk; Roman Ananiev; Andrey Koshurnikov; Denis Kosmach; Alexander Charkin; Nicolay Dmitrevsky; Victor Karnaukh; Alexey Gunar; Alexander Meluzov; Denis Chernykh

doi:10.1038/ncomms15872

Current rates and mechanisms of subsea permafrost degradation in the East Siberian Arctic Shelf

Nat Commun. 2017 Jun 22:8:15872. doi: 10.1038/ncomms15872.

Authors

Natalia Shakhova^{1

2}, Igor Semiletov^{1

2

3}, Orjan Gustafsson⁴, Valentin Sergienko⁵, Leopold Lobkovsky⁶, Oleg Dudarev^{1

3}, Vladimir Tumskoy^{7

8

9}, Michael Grigoriev¹⁰, Alexey Mazurov¹, Anatoly Salyuk³, Roman Ananiev⁶, Andrey Koshurnikov⁷, Denis Kosmach³, Alexander Charkin^{1

3}, Nicolay Dmitrevsky⁶, Victor Karnaukh³, Alexey Gunar⁷, Alexander Meluzov⁶, Denis Chernykh³

Affiliations

¹ National Tomsk Research Polytechnic University, 30 Prospect Lenina, Tomsk, Alaska 634050, Russia.
² International Arctic Research Center, University of Alaska Fairbanks, Akasofu Building, Fairbanks, Alaska 99775-7320, USA.
³ Pacific Oceanological Institute, Russian Academy of Sciences, 43 Baltiiskaya Street, Vladivostok 690041, Russia.
⁴ Department of Environmental Science and Analytical Chemistry, and the Bolin Centre for Climate Research, Stockholm University, Stockholm 10691, Sweden.
⁵ Institute of Chemistry, Russian Academy of Sciences, 100-Letiya Vladivostoka, Vladivostok 690022, Russia.
⁶ P.P. Shirshov Oceanological Institute, Russian Academy of Sciences, 36 Nahimovski Prospect, Moscow 117997, Russia.
⁷ Moscow State University, 1-12 Leninskie Gory, Moscow 119991, Russia.
⁸ Institute of Geography, Russian Academy of Sciences, 29 Staromonetniy Pereulok, Moscow 119017, Russia.
⁹ University of Tyumen, 6 Volodarskogo Street, Tyumen 625003, Russia.
¹⁰ Melnikov Permafrost Institute, Russian Academy of Sciences, 36 Merzlotnaya Street, Yakutsk 677010, Russia.

Abstract

The rates of subsea permafrost degradation and occurrence of gas-migration pathways are key factors controlling the East Siberian Arctic Shelf (ESAS) methane (CH₄) emissions, yet these factors still require assessment. It is thought that after inundation, permafrost-degradation rates would decrease over time and submerged thaw-lake taliks would freeze; therefore, no CH₄ release would occur for millennia. Here we present results of the first comprehensive scientific re-drilling to show that subsea permafrost in the near-shore zone of the ESAS has a downward movement of the ice-bonded permafrost table of ∼14 cm year^-1 over the past 31-32 years. Our data reveal polygonal thermokarst patterns on the seafloor and gas-migration associated with submerged taliks, ice scouring and pockmarks. Knowing the rate and mechanisms of subsea permafrost degradation is a prerequisite to meaningful predictions of near-future CH₄ release in the Arctic.

Publication types

Research Support, Non-U.S. Gov't