The East Siberian Arctic Shelf: towards further assessment of permafrost-related methane fluxes and role of sea ice

Natalia Shakhova; Igor Semiletov; Valentin Sergienko; Leopold Lobkovsky; Vladimir Yusupov; Anatoly Salyuk; Alexander Salomatin; Denis Chernykh; Denis Kosmach; Gleb Panteleev; Dmitry Nicolsky; Vladimir Samarkin; Samantha Joye; Alexander Charkin; Oleg Dudarev; Alexander Meluzov; Orjan Gustafsson

doi:10.1098/rsta.2014.0451

The East Siberian Arctic Shelf: towards further assessment of permafrost-related methane fluxes and role of sea ice

Philos Trans A Math Phys Eng Sci. 2015 Oct 13;373(2052):20140451. doi: 10.1098/rsta.2014.0451.

Authors

Natalia Shakhova¹, Igor Semiletov², Valentin Sergienko³, Leopold Lobkovsky⁴, Vladimir Yusupov⁵, Anatoly Salyuk⁶, Alexander Salomatin⁶, Denis Chernykh⁶, Denis Kosmach⁶, Gleb Panteleev⁷, Dmitry Nicolsky⁸, Vladimir Samarkin⁹, Samantha Joye⁹, Alexander Charkin⁶, Oleg Dudarev⁶, Alexander Meluzov⁴, Orjan Gustafsson¹⁰

Affiliations

¹ International Arctic Research Center, University of Alaska Fairbanks, Akasofu Building, Fairbanks, AK 99775-7320, USA Tomsk Polytechnic University, Institute of Natural Resources, Geology and Mineral Exploration, 30 Prospect Lenina, Tomsk, Russia nshakhov@iarc.uaf.edu.
² International Arctic Research Center, University of Alaska Fairbanks, Akasofu Building, Fairbanks, AK 99775-7320, USA Tomsk Polytechnic University, Institute of Natural Resources, Geology and Mineral Exploration, 30 Prospect Lenina, Tomsk, Russia Russian Academy of Sciences, Pacific Oceanological Institute, 43 Baltiiskaya Street, Vladivostok 690041, Russia.
³ Russian Academy of Sciences, Institute of Chemistry, 159, 100-Let Vladivostok Prospect, Vladivostok 690022, Russia.
⁴ Russian Academy of Sciences, P.P. Shirshov Oceanological Institute, 36 Nahimovski Prospect, Moscow 117997, Russia.
⁵ Russian Academy of Sciences, Institute on Laser and Information Technologies, 2 Pionerskaya Street, Troitsk 142092, Russia.
⁶ Russian Academy of Sciences, Pacific Oceanological Institute, 43 Baltiiskaya Street, Vladivostok 690041, Russia.
⁷ International Arctic Research Center, University of Alaska Fairbanks, Akasofu Building, Fairbanks, AK 99775-7320, USA.
⁸ University of Alaska Fairbanks, Geophysical Institute, Snow, Ice and Permafrost, PO Box 757320, Fairbanks, AK 99775-7320, USA.
⁹ Department of Marine Science, University of Georgia Atlanta, 3475 Lenox Road, NE Suite 300, Atlanta, GA 30326-3228, USA.
¹⁰ Department of Applied Environmental Science and Bolin Centre for Climate Research, Stockholm University, Stockholm 10691, Sweden.

Abstract

Sustained release of methane (CH(4)) to the atmosphere from thawing Arctic permafrost may be a positive and significant feedback to climate warming. Atmospheric venting of CH(4) from the East Siberian Arctic Shelf (ESAS) was recently reported to be on par with flux from the Arctic tundra; however, the future scale of these releases remains unclear. Here, based on results of our latest observations, we show that CH(4) emissions from this shelf are likely to be determined by the state of subsea permafrost degradation. We observed CH(4) emissions from two previously understudied areas of the ESAS: the outer shelf, where subsea permafrost is predicted to be discontinuous or mostly degraded due to long submergence by seawater, and the near shore area, where deep/open taliks presumably form due to combined heating effects of seawater, river run-off, geothermal flux and pre-existing thermokarst. CH(4) emissions from these areas emerge from largely thawed sediments via strong flare-like ebullition, producing fluxes that are orders of magnitude greater than fluxes observed in background areas underlain by largely frozen sediments. We suggest that progression of subsea permafrost thawing and decrease in ice extent could result in a significant increase in CH(4) emissions from the ESAS.

Keywords: East Siberian Arctic Shelf; methane emissions; sea ice; subsea permafrost.