Difference between revisions of "Glacier"

Glacial bodies larger than 50,000 km2 (19,000 sq mi) are called [[ice sheet|ice sheets]] or continental glaciers. Several kilometers deep, they obscure the underlying topography. Only [[nunataks]] protrude from their surfaces. The only extant ice sheets are the two that cover most of [[Antarctica]] and Greenland. They contain vast quantities of fresh water, enough that if both melted, global sea levels would rise by over 70 m (230 ft). Portions of an ice sheet or cap that extend into water are called ice shelves; they tend to be thin with limited slopes and reduced velocities. Narrow, fast-moving sections of an ice sheet are called ice streams. In Antarctica, many ice streams drain into large [[ice-shelf|ice shelves]]. Some drain directly into the sea, often with an [[ice tongue]], like Mertz Glacier.