8 -  Thermokarst

Methane bubbling in Siberia: Ebullition accounts for 95% of methane emissions. N Siberian lakes are underlain by Yedoma - organically rich Loess deposits from late Pleistocene. Organic matter underlying thermokarst lakes in the yedoma thaws enhancing the methane production. N Siberia has seen a 58% increase of lake methane emissions aided by thaw lake expansion.

Lake orientation in Alaska: Generally perpendicular to the prevailing wind direction. the cause has remained constant over time, determined by looking at the orientation of drained lake beds.

Holocene evolution of tundra landscapes: Most active stage 8-9 kyr BP. Annual temp estimated at 2-3 degrees higher than present. Second thermokarst stage at 5-4 kyr BP Low alas's and yedomas are most unstable and therefore active in current conditions.

Shape metric summary: the only similarity between lakes and dry thaw lake beds is long axis orientation. Lakes are more common on the arctic coastal plain  and more regularly shaped. basin coverage decreases with age of surface lake and DTLB density increase inland. Lake and DTLB become more dissimilar inland.

Walter et al. 2006

Cote & Burn 2002

Veremeeva & Gubin 2009

Hinkel et al. 2005