permafrost

[pur-muh-frawst, -frost]

noun

1. (in Arctic or subarctic regions) perennially frozen subsoil.

permafrost

/ ˈpɜːməˌfrɒst /

noun

1. ground that is permanently frozen, often to great depths, the surface sometimes thawing in the summer

permafrost

1. A layer of soil or bedrock that has been continuously frozen for at least two years and as long as tens of thousands of years. Permafrost can reach depths of up to 1,524 m (4,999 ft). It is found throughout most of the polar regions and underlies about one fifth of the Earth's land surface.

Word History and Origins

Origin of permafrost¹

First recorded in 1943; perma(nent) + frost

Word History and Origins

Origin of permafrost¹

C20: from _perma ( _nent ) + _frost

Example Sentences

Those who think history is by its nature a sort of settled permafrost will be surprised to see how the discipline has changed over the past half century.

Read more on The Wall Street Journal

These RNA sequences are the oldest ever recovered and come from mammoth tissue preserved in the Siberian permafrost for nearly 40,000 years.

Read more on Science Daily

The tundra had once been covered in a permanent layer of hard frozen soil, called permafrost.

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Canada and Russia, where large amounts of ice and permafrost are melting, are losing the most fresh water.

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"The thawing of permafrost at very high elevation led to the collapse of the summit," he explains.

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