TY - JOUR
T1 - The East Siberian Arctic Shelf
T2 - Towards further assessment of permafrost-related methane fluxes and role of sea ice
AU - Shakhova, Natalia Evgenievna
AU - Semiletov, Igor Petrovich
AU - Sergienko, Valentin
AU - Lobkovsky, Leopold
AU - Yusupov, Vladimir
AU - Salyuk, Anatoly
AU - Salomatin, Alexander
AU - Chernykh, Denis
AU - Kosmach, Denis
AU - Panteleev, Gleb
AU - Nicolsky, Dmitry
AU - Samarkin, Vladimir
AU - Joye, Samantha
AU - Charkin, Alexander
AU - Dudarev, Oleg Victorovich
AU - Meluzov, Alexander
AU - Gustafsson, Orjan
PY - 2015/10/13
Y1 - 2015/10/13
N2 - Sustained release of methane (CH4) to the atmosphere from thawing Arctic permafrost may be a positive and significant feedback to climate warming. Atmospheric venting of CH4 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 CH4 emissions from this shelf are likely to be determined by the state of subsea permafrost degradation. We observed CH4 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. CH4 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 CH4 emissions from the ESAS.
AB - Sustained release of methane (CH4) to the atmosphere from thawing Arctic permafrost may be a positive and significant feedback to climate warming. Atmospheric venting of CH4 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 CH4 emissions from this shelf are likely to be determined by the state of subsea permafrost degradation. We observed CH4 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. CH4 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 CH4 emissions from the ESAS.
KW - East siberian arctic shelf
KW - Methane emissions
KW - Sea ice
KW - Subsea permafrost
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U2 - 10.1098/rsta.2014.0451
DO - 10.1098/rsta.2014.0451
M3 - Article
AN - SCOPUS:84941247958
VL - 373
JO - Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
JF - Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
SN - 0962-8428
IS - 2052
M1 - 20140451
ER -