The cryosphere is the frozen water part of the Earth where the temperature is below 32º F (0º C) for at least part of the year.
The cryosphere consists of:
- ice and snow on land. This is the largest part of the cryosphere and includes the ice sheets in Greenland and Antarctica, along with the ice cap, glaciers, areas of snow, and permafrost.
- ice found on water. This includes frozen parts of the oceans around the Arctic and Antarctic, icebergs, frozen rivers and lakes
Snow and ice reflect heat from the sun, helping to regulate the Earth’s temperature. The polar regions are some of the most sensitive to climate change.
Permafrost is permanently frozen ground that remains at or below 0ºC (32ºF) for at least two years and can range from 1 – 1,000 meters in depth. It can contain over 30% ice or practically no ice at all. It is found in Greenland, Alaska, Russia, China and Eastern Europe and covers approximately 22.8 million square kilometers (8.8 million square miles). That’s about 24% of the land surface of the Northern Hemisphere.
There are four types:
- Sporadic permafrost – isolated pockets of permanently frozen ground
- Isolated permafrost – less that 10% of the ground is permanently frozen
- Discontinuous permafrost – 50-90% of the ground is permanently frozen
- Continuous permafrost – a continuous sheet of frozen permanently ground
Permafrost has been mapped since the mid 20th century. The first International Conference on Permafrost was held in the USA in 1963. The International Permafrost Association (IPA) was formed in 1983.
Finally, we can take a look at the important biosphere ecosystem.