The East Siberian Arctic Shelf: towards further assessment of permafrost-related
methane fluxes and role of sea ice
#MMPMID26347539
Shakhova N
; Semiletov I
; Sergienko V
; Lobkovsky L
; Yusupov V
; Salyuk A
; Salomatin A
; Chernykh D
; Kosmach D
; Panteleev G
; Nicolsky D
; Samarkin V
; Joye S
; Charkin A
; Dudarev O
; Meluzov A
; Gustafsson O
Philos Trans A Math Phys Eng Sci
2015[Oct]; 373
(2052
): ? PMID26347539
show ga
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.
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