Yedoma
Yedoma – carbon-rich Ice Complex – is Pleistocene-age permafrost (formed during last Ice Age) that contains a significant amount of organic material with ice content of 50 to 90% by volume.
Yedoma covers around one million square kilometres along the 7000-km coastline of the East Siberian Arctic Shelf.
Thawing yedoma is a significant source of atmospheric methane and contributes to retreat of eastern Siberian and Alaskan coastlines.
Image: Yedoma distribution http://apgc.awi.de (Creative Commons Attribution 4.0 License).