What is Permafrost?

Mary McMahon
Mary McMahon

Permafrost is soil that has remained at or below the freezing point for two or more years. The term is actually a bit misleading, as no frost is required. Permanently frozen bedrock, for example, can also be referred to as permafrost, as can very dry frozen soil. Between 20-25% of the Earth's surface is covered in permafrost — also known as cryotic soil — although this number began to fluctuate wildly in the early 21st century due to global warming.

Siberia is known for its permaforst and desolate landscape.
Siberia is known for its permaforst and desolate landscape.

For soil to get this way, the climate has to be extremely cold. Most of the time soil in this condition closely mirrors air temperature, and is found in the polar regions of the world. Alpine permafrost is found in mountainous areas in regions of lower latitude, and other similar can be found spotted across the Earth's surface. In some cases, permafrost is hundreds of thousands of years old, in which case it is considered to be “fossilized,” accumulated over a period of time which took thousands of years and impossible to melt in current climate conditions.

As one might imagine, cryotic soil has a radical impact on the regions where it is found. It inhibits plant growth which makes it difficult for animals to thrive. It also helps resist erosion, as it essentially cements the soil together, and it presents a number of challenges to people. Building on permafrost is tricky, because if it melts then the structures built on top of it can collapse. Likewise, utility pipes in regions with cryotic soil must be run above the ground for safety, as they could melt the soil and cause a problem, or they could crack open if the soil melted and the ground settled.

Researchers are especially interested in the areas of “continuous permafrost,” where cryotic soil is extensive and it has been present for an extended period of time. This often creates distinctive patterns in the ground which can be interesting to observe, and the spread or shrinking of the soil can be an indicator of environmental problems. In Arctic nations, for example, the shrinking permafrost line has contributed substantially to erosion.

The permafrost regions of the world are also of interest to archaeologists and historians. Frost is an excellent preservative, literally freezing artifacts in time. In addition to finding human and animal remains in cryotic soil, researchers have also found organic materials like textiles, leather, and baskets which would normally decay.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


Thawing permafrost helps speed up global warming, which is not a good thing. We’ve all heard that ice near the polar regions is melting. Along with it, permafrost that has been in place for centuries or longer is thawing as the Earth warms.

My dad works for a company funded by the government that is looking for ways to combat global warming. He told me that when permafrost thaws, carbon dioxide and methane are released into the air. When they get to the atmosphere, they hold the Earth’s heat in, and since it has nowhere to go, this heat makes additional permafrost thaw.


@lighth0se33 - The permafrost in Siberia has preserved more than just mammoths. I read that archaeologists found five well-preserved mummies wearing copper plates in the permafrost there. The copper had kept the bodies from oxidizing.

Other frozen Siberian finds include a princess covered in tattoos and a man holding a fur coat and wearing some sort of ornament on his head. It really makes me want to go there with some heavy excavating equipment.

Some people say we should not be disturbing the dead by excavating their remains. That may be true, but we sure do learn a lot about history by examining mummies.


I would hate to live in an area with permafrost. I love to grow my own fruits and vegetables, as well as flowers for decoration. I don’t think I could enjoy a life where I couldn’t work the soil.

People who prefer to stay indoors all the time don’t mind the permafrost. My cousin lives in an area that is perpetually cold, and she just doesn’t go outside except to go to her car.

She entertains herself by reading books, playing video games, cooking, and having friends over. Because she has never had the chance to work in a garden, she does not mind the permafrost one bit.


I read that permafrost has done a great job of preserving mammoths in Siberia. One young mammoth found frozen still had its eyes and trunk. I saw a picture of it, and at first, I thought it was a baby elephant that had just died.

It’s so common to find mammoths in the permafrost of Siberia that regular citizens excavate them to sell the tusks and fur. This is illegal, because any mammoths found there are supposed to be property of the government, but those who do find them make a huge profit.

It’s scary how permafrost can preserve entire creatures as big as mammoths. I wouldn’t be surprised if scientists one day find an entire city preserved in ice.

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