(Çevre) A polar ice cap or polar ice sheet is a high-latitude region of a planet or moon that is covered in ice. There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor any geological requirement for it to be over land; only that it must be a body of solid phase matter in the polar region. This causes the term 'polar ice cap' to be somewhat of a misnomer, as the term ice cap itself is applied with greater scrutiny as such bodies must be found over land, and possess a surface area of less than 50,000 km²: larger bodies are referred to as ice sheets
A dome-shaped glacier covering an area greater than 50,000 square kilometers Greenland and Antarctica are considered ice sheets During the glacial advances of the Pleistocene ice sheets covered large areas of North America, Europe, and Asia Larger than an ice cap
A large, continental glacier that is not confined by the underlying topography The northeastern quarter of North America was covered about a dozen times by the Laurentide Ice Sheet during the Ice Age, between 2 5 million and 10,000 years ago Today, ice sheets are found only in polar regions such as Greenland and Antarctica
A glacier of considerable thickness and more than 50,000 sq km in area It forms a continuous cover of ice and snow over a land surface An ice sheet is not confined by the underlying topography but spreads outward in all directions During the Pleistocene Epoch, ice sheets covered large parts of North America and northern Europe but they are now confined to polar regions (e g , Greenland and Antarctica) (Source: Carbon Dioxide Information Analysis Center, 1990)
A mass of land ice which is sufficiently deep to cover most of the underlying bedrock topography, so that its shape is mainly determined by its internal dynamics (the flow of the ice as it deforms internally and slides at its base) An ice sheet flows outwards from a high central plateau with a small average surface slope The margins slope steeply, and the ice is discharged through fast-flowing ice streams or outlet glaciers, in some cases into the sea or into ice-shelves floating on the sea There are only two large ice sheets in the modern world, on Greenland and Antarctica, the Antarctic ice sheet being divided into East and West by the Transantarctic Mountains; during glacial periods there were others
Very large areas of ice, such as those covering much of Greenland and Antarctica today During the Quaternary, ice sheets covered much of the Northern Hemisphere