Alaska's permafrost, which stores greenhouse gases, is less plentiful and more fragile than believed
Related: Absence of ice-bonded permafrost beneath an Arctic lagoon revealed by electrical geophysics (Science Advances)
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Source: Washington Post
Alaska’s permafrost, which stores greenhouse gases, is less plentiful and more fragile than believed, study says
By Erin Blakemore
11/7/2020, 8:00:00 a.m.
Scientists long thought that the ground beneath the northern coasts of Alaska was permanently frozen. That was good news; permafrost stores large amounts of carbon, methane and other planet-warming gases, and coastal permafrost was thought to be a critical buffer against both global warming and coastal erosion.
That model could be very wrong. A new study documents an absence of permafrost along a coastal site in northeastern Alaska — and warns that coastal permafrost is more fragile than once thought. The study in the journal Science Advances documents efforts to map the subsurface of the Kaktovik Lagoon, a shallow bay at the edge of a large tundra underpinned by permafrost.
But electrical resistivity imaging of the beach and seafloor shows that both were ice-free to at least 65 feet.
That leaves the area vulnerable to coastal erosion, since the land near the shore is not protected by the freeze.
Another surprise was that the tundra, thought to be underpinned by a deep layer of permafrost, only had it down to about 16 feet.
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Read more: https://www.washingtonpost.com/science/alaska-permafrost-greenhouse-gas-carbon/2020/11/06/e7c5b676-1ed8-11eb-ba21-f2f001f0554b_story.html
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