Sunken Earth

Observation by Cynthia Paniyak:

I was sent some pictures on some area of the tundra West from Chevak is sinking. The pictures show how it is falling down with some water in the middle, as well as some grass. This area is far from the river or bay that are tidal influenced.

Comments from LEO Editors:

This observation has been shared with the Permafrost Laboratory at the University of Alaska Fairbanks.

In an Anchorage Daily News Article about permafrost thaw in Bethel, UAF permafrost scientist Vladimir Romanavsky describes the permafrost in the YK delta as "warm." The temperature of the permafrost is just below freezing, making it sensitive to warmer than average air temperatures. Above the permafrost, there is an "active layer" of soil that freezes and thaws every year. As temperatures rise, permafrost closer to the surface is thawing and the active layer is becoming bigger. Bethel contractors quoted in the same article say that 30 years ago they would encounter permafrost 4-6 feet below the surface - today, they find it 8-12 feet below the surface.

LEO has received several other observations of permafrost western Alaska. In 2012, Carol Oliver in Golovin commented that a nearby trail was thawing and widening, releasing a sulfur-like odor. Similarly, in 2014, Robert Hairell reported a thawing ATV trail near Chuathbaluk. In 2017, Sandra Hill shared that as permafrost thawed near Hooper Bay, lakes that have been around for her entire life are draining. Erica Lujan