Glaciers

The term glacier refers to large deposits of permanent ice. Glaciers do not melt, during the summer, or else they melt so slowly most of the ice is still present, when the next winter comes.

Temperatures drop, due to thinner air pressure, on mountain peaks, and permanent glaciers can be found atop mountains even in tropic zones, with the most famous exammple being the snows of Mount Kilamanjaro. These mountain top glaciers are known as alpine glaciers.

The glaciers formed during an ice age can cover most or all of a continent, and can be kilometers deep. Greenland, Antarctica, some of the World's largest alpine glaciers are remants of the last ice age.