Permafrost

Definition

Permafrost is permanently frozen ground that remains at or below 0°C for at least two consecutive years. It is commonly found in polar regions and high mountain areas.

5 Must Know Facts For Your Next Test

1. Permafrost covers about 24% of the Northern Hemisphere's land area.
2. It plays a crucial role in the carbon cycle by storing large amounts of organic carbon.
3. Thawing permafrost can release greenhouse gases like methane and carbon dioxide, contributing to climate change.
4. Vegetation in permafrost regions is typically limited to hardy shrubs, mosses, and lichens due to the harsh conditions.
5. Infrastructure built on permafrost must account for potential ground instability caused by thawing.

Review Questions

• What percentage of the Northern Hemisphere's land area is covered by permafrost?
• How does thawing permafrost contribute to climate change?
• What types of vegetation are commonly found in permafrost regions?

Related terms

Tundra:

A biome characterized by cold temperatures, low biodiversity, and a landscape dominated by ice and snow.

Methane:

A potent greenhouse gas that can be released from thawing permafrost and contributes significantly to global warming.

Carbon Cycle: The process through which carbon is exchanged between different components of the Earth, including the atmosphere, biosphere, oceans, and geosphere.