The cryosphere is the area of the Earth's surface that is covered by solid water. Sea ice, lake ice, river ice, snow cover, glaciers, ice caps, ice sheets, and frozen land are all included. The term "cryosphere" comes from the Greek kryos (ice) and sphere (round). What was once open water becomes ice at both the sea and the land border of the Arctic Ocean. At least half of the Arctic Ocean is now covered by ice in winter, much of it multi-year ice that has been frozen for several years.
Two of the three largest ice bodies on Earth are found in Antarctica: Ice sheet and glacier. The third is Greenland, which has an ice cap instead of a glacier system.
Antarctica contains more ice than any other continent combined. If all this ice were to melt, it would cause a global rise in sea level worth about 7 meters (23 feet). But most of it is frozen into ice shelves and bays that connect to the ocean, so it does not contribute to sea level change directly. Instead, it changes the shape of Earth's gravity field, which affects how much energy is absorbed by the oceans during earthquakes or volcanic eruptions far away from Antarctica.
Greenland is another story though.
The cryosphere is the Earth's frozen water system. This includes sections of the ocean that are frozen, such as the waters surrounding Antarctica and the Arctic. It also includes large bodies of ice within continents, such as Greenland and West Antarctica. In addition, it includes small bodies of water such as ponds and lakes that are frozen over most of the year. Finally, it includes rivers and streams that are frozen over most of the year, except during certain periods when they are not frozen solid but instead contain liquid water.
When you think of a frozen pond, you have many different images in your mind: a skating rink, a car tire track in the snow, etc. All of these images are part of what makes up the cryosphere. The term "cryosphere" comes from the Greek kryos (ice) + sphere (shape).
In science, the cryosphere is the portion of the Earth's surface covered by ice or other cold substances. The phrase "the cryosphere", like other phrases used to describe parts of Earth's environment, is commonly used by scientists to help identify research being done on topics related to each component. For example, scientists study glaciers because they are interested in how ice moves across land surfaces and how this affects the Earth's geometry.
"Cryosphere" is derived from the Greek word "krios," which meaning "cold." The cryosphere includes ice and snow on land. This comprises the cryosphere's major components, the continental ice sheets of Greenland and Antarctica, as well as ice caps, glaciers, and snow and permafrost regions. The remaining parts of the cryosphere include the oceanic ice shelves and sea ice, icebergs, and frozen ground such as alpine and polar deserts.
The largest part of the cryosphere is the Antarctic Ice Sheet, which covers 810,000 square miles (2100,000 km2) and accounts for 90% of the continent's mass loss from its interior. The next largest component is the Greenland Ice Sheet, which covers 795,000 square miles (2050,000 km2) and accounts for 9% of the continent's mass loss.
Other large-scale features of the cryosphere include the North American and Eurasian ice sheets, which together account for another 6% of the continent's mass loss; ice shelves in Antarctica; and sea ice in the Arctic and other oceans. Frozen soil makes up less than 1% of the cryosphere.
Minor components of the cryosphere include mountain glaciers around the world; ice caps and domes in places such as Mount Kilimanjaro, Kenya; and small patches of frozen water in arid regions like the Atacama Desert, Chile.
The cryosphere is commonly thought to reside at the top and bottom of our world, in the polar regions. The area around the North Pole is known as the Arctic, while the area surrounding the South Pole is known as the Antarctic. However, snow and ice may also be found in many other places on Earth. For example, large amounts of fresh water ice are found in Antarctica's lakes and rivers. In fact, one-third of all the freshwater on Earth is stored in Antarctica's ice shelves and glaciers.
Some scientists now believe that parts of Mars may have had water on its surface in its early years. If this is true, it could have been possible for life to develop there later. Scientists think that the conditions might have been right for some type of organism to exist before all the water was lost from Mars' atmosphere or boiled away by the sun.
Earth's cryosphere can change over time. For example, during a solar eclipse you can see things like shadows and colors around the edge of the moon that indicate which parts of Earth's surface are blocking light from reaching it. These are called "earthshine" effects. As sunlight reaches the surface of Earth, some of it is reflected back into space and some of it is absorbed by molecules in the atmosphere (especially water vapor) which then re-emit that energy in the infrared part of the spectrum. From here, it can be re-radiated back into space in what are called "infrared glows".