Cryosphere

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Published: August 16, 2010, 7:45 pm

Updated: December 5, 2021 5:44 pm

Author: U.S. Snow and Ice Data Center
Topic Editor: Daniel Mietchen

Topic Editor: C. Michael Hogan

Source: NSIDC
Topics:
Geology (main)

Introduction

Igloo.jpg People around the world, including this Inuit man, rely on snow and ice to continue their way of life. (Source: NSIDC and CorelDRAW Photos)

Some places on Earth are so cold that water is in solid form as ice or snow. Scientists call these frozen places of our planet the "cryosphere." The word "cryosphere" comes from the Greek word for cold, "kryos."

Why does the cryosphere matter?

The cold regions of our planet influence our entire world’s climate. Plus, the cryosphere is central to the daily lives of the people, plants, and animals that have made it their home.

Cryosphere Geography

Seaice.jpg Sea ice is one important aspect of both the Arctic region and Antarctica. (Source: Todd Arbetter and NSIDC)

When scientists talk about the cryosphere, they mean the places where water is in its solid form, where low temperatures freeze water and turn it into ice.

People most often think of the cryosphere as being at the top and bottom of our planet, in the polar regions. We call the area around the North Pole the Arctic and the area around the South Pole the Antarctic. But snow and ice are also found at many other locations on Earth.

The Arctic

150px-OlympicNP.jpg The frozen lands of the cryosphere exist beyond the polar regions, in places like the Olympic Wilderness in Washington. Source: National Park Service)

The North Pole is covered by a cold ocean called the Arctic Ocean. In the Arctic Ocean, sea ice (Sea ice in the Arctic) grows in the winter and shrinks in the summer.

Frozen ground including permafrost ring the Arctic Ocean. Glaciers, snow, and ice cover the nearby land, including a thick sheet of snow and ice covering Greenland.

Antarctica

Antarctica, at Earth's South Pole, is an icy continent. A huge ice sheet covers the land mass of Antarctica and, in some places, shelves of floating ice extend into the ocean. Similarly like in the Arctic, the outer sections of ice break off or "calve" from these shelves and form icebergs. The icebergs float in the oceans, melting and falling apart as they drift into warmer waters.

And In between

The cryosphere also exists in places far away from the cold poles, at high elevations. For example, the snow on Mount Kilimanjaro is in Africa. Frozen soil can be found high in the mountains of the United States, as well as in the northern reaches of Canada, China, and Russia, often in the form of Permafrost.

The cryosphere expands during the cold winter months. Seasonal areas of the cryosphere include places where snow falls, and where soil, rivers, and lakes freeze.

Contents of the Cryosphere

Snow, ice, or both are key ingredients in every aspect of the cryosphere, including sea ice (Sea ice in the Arctic), glaciers, ice shelves, icebergs, and frozen ground.

Snow

Snow.jpg Snow is precipitation that falls to the ground as ice crystals. (Source: NSIDC and CorelDRAW Photos)
150px-Ice.jpg Ice is the basis for glaciers, sea ice, ice shelves, icebergs, and frozen ground. (Source: NSIDC and Stock.xchng)

Snow is precipitation made up of ice crystals. When cold temperatures and high humidity levels combine in the atmosphere (Atmosphere layers), snow crystals form. As long as air temperature remains below freezing, the crystals will fall to the Earth as snow. Snow:

  1. can be found all over the world, even near the equator at high elevations
  2. reflects sunlight (Solar radiation) and affects our planet’s climate
  3. provides a habitat for some animals and plants
  4. supplies water for people, plants, and animals around the world
  5. is an important part of the world’s climate.

Ice

Icebergs.jpg Arctic sea ice influences our entire planet's climate. (Source: NSIDC and CorelDRAW Photos)

Ice forms when temperatures drop below the freezing point and liquid water becomes a solid, creating a tightly bonded substance. Ice is a key ingredient in glaciers, sea ice, ice shelves, icebergs, and frozen ground. Naturally occurring ice:

  1. exists all over the world, but mostly forms in the high latitudes, at high elevations, or at night when temperatures cool
  2. may occur in oceans, lakes, and rivers; much of the world sea ice is expanding in the last decade. (Matkin. 2021)
  3. provides water for people, animals, and plants
  4. on lakes and in oceans can get so thick that special ships called icebreakers have to create a path through the ice
  5. can tell scientists about the past climate of Earth through ice cores.

Sea ice

Icetrek.jpg Scientists on an iceberg in Antarctica prepare for field research during the NSIDC IceTrek expedition. (Source: NSIDC)

Sea ice forms when water in the oceans is cooled to temperatures below freezing. Most sea ice forms in the Arctic and Antarctic Oceans. Sea ice:

  1. does not raise sea level when it melts, because it forms from ocean water
  2. is closely linked with our planet’s climate, and recently is expanding
  3. fills a central role in the lives and customs of native Arctic people
  4. provides a place for polar bears, seals, and other animals to live
  5. is one way that scientists study the effects of climate .

Glaciers

Glaciers are thick masses of ice on land. The ice has built up from many seasons of snowfall. Glaciers move downhill very slowly. Glaciers:

  1. cover 10 percent of the world’s land
  2. sometimes look pink because of the algae living in the top layers of the snow and ice
  3. store 75 percent of the world’s freshwater and provide water for many people around the world
  4. change the land they flow through, carving landscapes with their weight.

Ice shelves and icebergs

250px-Pair example small.jpg Muir Glacier in Alaska, like many glaciers, has changed through time. At left, the glacier in 1941; at right, the glacier in 2004. (Source: NSIDC)

Ice shelves are platforms of ice that form where ice sheets and glaciers move out into the oceans. Ice shelves are found chiefly in Antarctica and Greenland, as well as in the Arctic near Canada and Alaska. Icebergs are chunks of ice that break off glaciers and ice shelves and drift in the oceans. Ice shelves and icebergs:

  1. raise sea level only when they first leave land and push into the water, but not when they melt in the water
  2. break off and melt when temperatures rise; in 2002, Antarctica’s Larsen B Ice Shelf shattered once in only a few months, sending hundreds of icebergs into the ocean
  3. provide shelter for krill and small fish that penguins, seals, whales, and sea birds consume
  4. are one important subject area for a wide range of scientists who study biology, glaciers, climate, and oceans
  5. may hold clues to the future of ice sheets and glaciers.

Frozen ground

Frozenground.jpg Melting permafrost beneath this building in Dawson, Yukon, is making the building tip. (Source: University of Iowa Geoscience Slides Collection)

Frozen ground is soil or rock in which part or all of the water has frozen. If the ground is frozen all year long, we call it "permafrost," or permanently frozen ground. Frozen ground:

  1. exists mostly in the Arctic and Antarctic, but frozen ground can also be found at high elevations
  2. often has an "active layer" near the surface, where plants can live because the soil is thawed for at least part of the year
  3. creates problems for people who are building structures, roads, or dams because it can shift them when it melts
  4. stores greenhouse gases like carbon dioxide and methane; scientists are studying how these gases will affect climate if temperatures change..

See Also

References

  • James G Matkin (2021) "The Earth is Actually Cooling" NASA says due to low sun activity: Record Plunge despite Rising CO2. The 0.8* C increase over 140 years is too small and within the range of natural variability to constitute human-made global warming.
  • Meredith, Michael P. , Nicholls, Keith W. , Renfrew, Ian A., Boehme, Lars, Biuw, Martin, Fedak, Mike (2011) Seasonal evolution of the upper-ocean adjacent to the South Orkney Islands, Southern Ocean: results from a “lazy biological mooring”. British Antarctic Survey. Natural Environment Research Council
  • Ola M. Johannessen, ‎Leonid P. Bobylev, ‎Elena V. Shalina (2019) Sea Ice in the Arctic: Past, Present and Future. Springer Publishing
  • Ian Simmonds (2017) Comparing and contrasting the behaviour of Arctic and Antarctic sea ice over the 35 year period 1979-2013. Published online by Cambridge University Press:  26 July 2017
  • U.S. National Snow and Ice Data Center (2021) Arctic Sea Ice News and Analysis
Disclaimer: This article contains information that was originally published by the National Snow and Ice Data Center. Topic editors and authors for the Encyclopedia of Earth have edited its content and added new information. The use of information from the National Snow and Ice Data Center should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

Citation

U. S. Snow and Ice Data Center (2010). Cryosphere. eds. Daniel Mietchen and C. Michael Hogan. Encyclopedia of Earth. National Council for Science and Environment. Washington DC. Retrieved from http://editors.eol.org/eoearth/wiki/Cryosphere