Pub. date: 2008 | Online Pub. Date: April 25, 2008 | DOI: 10.4135/9781412963893 | Print ISBN: 9781412958783 | Online ISBN: 9781412963893| Publisher:SAGE Publications, Inc.About this encyclopedia
Antarctic Ice Sheets
ICE COVERS MUCH of the polar regions of Earth, and is a critical component to the planets climate. An ice sheet is defined as a mass of ice that is greater than 31,067 mi. (50,000 km.) in area, such as those of Antarctica and Greenland. Ice sheets should not be confused with ice caps, which are masses of ice covering less than 31,067 mi. (50,000 km.) in area. It is estimated that approximately 90 percent of the Earths total ice mass, or 27 million cu. km., is located in the Antarctic Ice Sheet. Scientists are concerned that increasing temperatures of air and sea will cause significant melting of the worlds ice, including the Antarctic Ice Sheets, causing sea level rise. Ice sheets, glaciers, ice caps, permafrost, snow, and sea ice are all components of the Earths cryosphere (portions of the Earths surface that are frozen over land or water). In ...