from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Permanently frozen subsoil, occurring throughout the Polar Regions and locally in perennially frigid areas.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Permanently frozen ground, or a specific layer thereof.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. ground that is permanently frozen
The temperature in the permafrost is rising in Alaska, northwest Canada, Siberia and Northern Europe.
Beyond affecting the humans and wildlife that call the area home, the Arctic's warmer temperatures and decreases in permafrost, snow cover, glaciers and sea ice also have wide-ranging consequences for the physical and biological systems in other parts of the world.
"Beyond affecting the humans and wildlife that call the area home, the Arctic's warmer temperatures and decreases in permafrost, snow cover, glaciers and sea ice also have wide-ranging consequences for the physical and biological systems in other parts of the world," NOAA Administrator Jane Lubchenco said in a statement.
"Subsea permafrost is losing its ability to be an impermeable cap," Natalia Shakhova, a scientist at the University of Fairbanks, Alaska, said in a statement.
Such sorting, together with longer term permafrost degradation, movement of soils on slopes, and displacement by moving compacted snow and ice, exerts strong forces on plant roots.
Brad Arnold says: â€¢ There is an estimated 400 billion tons of methane trapped in permafrost ice. â€¢ An estimated 50% of surface permafrost will melt by 2050, and 90% by 2100. â€¢ Methane is more than 20 times as strong a greenhouse gas as CO2-the sudden release of just 35 billion tons of methane would be like doubling the CO2 in the air.
The “flip-side” of having large amounts of methane gas gradually escape the Arctic’s thawing permafrost is that some of it could eventually be harnessed to generate electricity.
This isn’t so preposterious a senario, because there is an est. 400 billion tons of methane locked up in permafrost ice, and an est. 10,000 billion tons of methane locked up in the ocean bottom.
I am from Alaska where the permafrost is now melting (” perma” frost – it never melts – but wait? huh? never? well the permafrost is melting now!) – something my grandparents (who also lived in Alaska) never saw in there lifetimes.
Much of the Arctic Circle is covered with permafrost, which is defined as any rock or soil that maintains a below-freezing temperature for at least two years. permafrost may or may not actually contain any ice.
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