THE TERM “PERMAFROST” refers to ground that remains frozen for at least two straight years. Permafrost is most common in regions with high mountains and in higher latitudes; it covers large regions of the Earth. Although the ground is frozen, permafrost regions are not always covered in snow. Permafrost is made of a combination of soil, rocks, and sand that are held together by ice. Near the surface, permafrost soils contain large quantities of organic carbon from dead plants that couldn’t decompose due to the cold. (NASA)
Get used to that word as we are going to be hearing lots more about it in the future. For example, here are a few paragraphs from “As climate change melts Alaska’s permafrost, roads sink, bridges tilt and greenhouse gases release” by Hal Bernton for The Seattle Times (December 15, 2019):
“Alaska’s permafrost is under assault from a warming climate, and it’s happening a lot faster than anticipated. Hillside slopes have liquefied, unleashing slides that end up as muddy deltas in salmon streams. The ground under the Nome airport runway—key to linking the community to the outside world—has thawed, requiring costly patches. And during the hottest July on record, a sinkhole 14 feet deep opened along a main roadway in the city.
For a region where climate change also is bringing profound changes offshore, these are disruptive developments. As the northern Bering Sea warms, bird and marine mammal die-offs are on the rise and winter ice is on the decline, enabling storms to gain strength over open water and slam into coastal communities like Teller.
The accelerating melt is a global concern: Permafrost, which mostly lies in the northern reaches of the planet, is a vast carbon storehouse of frozen plants and animals that release greenhouse gases as they warm and decompose.”
To read this article in its entirety, click here.
FEATURED IMAGE: The photo at the top of this page is a cliff of permafrost along the Itkillik River in northern Alaska being eroded by the river. (Photo: Mikhail Kanevskiy / University of Alaska Fairbanks, Institute of Northern Engineering)