Permafrost : New Discovery
In a discovery in Siberia, scientists recently uncovered a 44,000-year-old wolf, nearly perfectly preserved in permafrost.
- Permafrost is any ground that remains completely frozen—32°F (0°C) or colder—for at least two years straight.
- These permanently frozen grounds are most common in regions with high mountains and in Earth’s higher latitudes—near the North and South Poles.
- Permafrost can be found on land and below the ocean floor.
- Permafrost thickness can range from one meter (about three feet) to more than 1,000 meters (about 3,281 feet), covering entire regions, such as the Arctic tundra, or a single, isolated spot, such as a mountaintop of alpine permafrost.
- Permafrost covers large regions of the Earth. Almost a quarter of the land area in the Northern Hemisphere has permafrost underneath.
- While two years is the minimum for permafrost consideration, some regions have had frozen ground for hundreds of thousands of years.
- Scientists discovered the oldest known permafrost in Siberia, which has been frozen for the past 650,000 years.
- Permafrost is made of a combination of soil, rocks, and sand that are held together by ice.
- The soil and ice in permafrost stay frozen all year long.
- Although the ground is frozen, permafrost regions are not always covered in snow.
- Near the surface, permafrost soils also contain large quantities of organic carbon—a material leftover from dead plants that couldn’t decompose, or rot away, due to the cold.
- Lower permafrost layers contain soils made mostly of minerals.
- A layer of soil on top of permafrost does not stay frozen all year. This layer, called the active layer, thaws during the warm summer months and freezes again in the fall.
- In colder regions, the ground rarely thaws—even in the summer. There, the active layer is very thin—only 4 to 6 inches (10 to 15 centimeters). In warmer permafrost regions, the active layer can be several meters thick.
- A thawing permafrost layer can lead to severe impacts on people and the environment.
- For instance, as ice-filled permafrost thaws, it can turn into a muddy slurry that cannot support the weight of the soil and vegetation above it.
Infrastructure such as roads, buildings, and pipes could be damaged as permafrost thaws. - Additionally, organic matter (like the remains of plants) currently frozen in the permafrost will start to decompose when the ground thaws, resulting in the emission of methane and carbon dioxide into the atmosphere. This contributes to further global climate change.
