Changes

==Origin==

==Origin==

French, from Middle French [[dialect]] (Franco-Provençal), from ''glace'' ice, from [[Latin]] ''glacies''; akin to Latin ''gelu'' frost

French, from Middle French [[dialect]] (Franco-Provençal), from ''glace'' ice, from [[Latin]] ''glacies''; akin to Latin ''gelu'' frost

*[http://en.wikipedia.org/wiki/18th_century 1744]

*[https://en.wikipedia.org/wiki/18th_century 1744]

The processes and features caused by ''glaciers'' and related to them are referred to as ''glacial''. The [[process]] of glacier establishment, [[growth]] and [[flow]] is called ''glaciation''. The corresponding area of [[study]] is called [http://en.wikipedia.org/wiki/Glaciology glaciology]. Glaciers are important components of the global [http://en.wikipedia.org/wiki/Cryosphere cryosphere].

The processes and features caused by ''glaciers'' and related to them are referred to as ''glacial''. The [[process]] of glacier establishment, [[growth]] and [[flow]] is called ''glaciation''. The corresponding area of [[study]] is called [https://en.wikipedia.org/wiki/Glaciology glaciology]. Glaciers are important components of the global [https://en.wikipedia.org/wiki/Cryosphere cryosphere].

==Definitions==

==Definitions==

*1: a large body of ice moving slowly down a slope or [[valley]] or spreading outward on a [[land]] surface

*1: a large body of ice moving slowly down a slope or [[valley]] or spreading outward on a [[land]] surface

==Description==

==Description==

A '''glacier''' is a large [[persistent]] body of ice that forms where the accumulation of snow exceeds its [http://en.wikipedia.org/wiki/Ablation ablation] (melting and sublimation) over many years, often centuries. Glaciers slowly deform and flow due to [[stresses]] induced by their weight, creating [http://en.wikipedia.org/wiki/Crevasse crevasses], [http://en.wikipedia.org/wiki/Serac seracs], and other distinguishing features. They also abrade rock and debris from their substrate to create landforms such as [http://en.wikipedia.org/wiki/Cirque cirques] and [http://en.wikipedia.org/wiki/Moraine moraines]. Glaciers form only on land and are distinct from the much thinner [http://en.wikipedia.org/wiki/Sea_ice sea ice] and lake ice that form on the surface of bodies of [[water]].

A '''glacier''' is a large [[persistent]] body of ice that forms where the accumulation of snow exceeds its [https://en.wikipedia.org/wiki/Ablation ablation] (melting and sublimation) over many years, often centuries. Glaciers slowly deform and flow due to [[stresses]] induced by their weight, creating [https://en.wikipedia.org/wiki/Crevasse crevasses], [https://en.wikipedia.org/wiki/Serac seracs], and other distinguishing features. They also abrade rock and debris from their substrate to create landforms such as [https://en.wikipedia.org/wiki/Cirque cirques] and [https://en.wikipedia.org/wiki/Moraine moraines]. Glaciers form only on land and are distinct from the much thinner [https://en.wikipedia.org/wiki/Sea_ice sea ice] and lake ice that form on the surface of bodies of [[water]].

On [[Earth]], 99% of glacial ice is contained within vast ice sheets in the [http://en.wikipedia.org/wiki/Polar_region polar regions], but glaciers may be found in [[mountain]] ranges of every [[continent]] except Australia, and on a few high-latitude [http://en.wikipedia.org/wiki/Oceanic_island oceanic islands]. Between 35°N and 35°S, glaciers occur only in the [http://en.wikipedia.org/wiki/Himalayas Himalayas], [http://en.wikipedia.org/wiki/Andes Andes], a few high mountains in East Africa, Mexico, New Guinea and on [http://en.wikipedia.org/wiki/Zard_Kuh Zard Kuh in Iran].

On [[Earth]], 99% of glacial ice is contained within vast ice sheets in the [https://en.wikipedia.org/wiki/Polar_region polar regions], but glaciers may be found in [[mountain]] ranges of every [[continent]] except Australia, and on a few high-latitude [https://en.wikipedia.org/wiki/Oceanic_island oceanic islands]. Between 35°N and 35°S, glaciers occur only in the [https://en.wikipedia.org/wiki/Himalayas Himalayas], [https://en.wikipedia.org/wiki/Andes Andes], a few high mountains in East Africa, Mexico, New Guinea and on [https://en.wikipedia.org/wiki/Zard_Kuh Zard Kuh in Iran].

Glacial ice is the largest reservoir of [http://en.wikipedia.org/wiki/Freshwater freshwater] on Earth, supporting one third of the world's [[population]].  Many glaciers store water during one [[season]] and release it later as meltwater, a water source that is especially important for [[plants]], [[animals]] and [[human]] uses when other sources may be scant.

Glacial ice is the largest reservoir of [https://en.wikipedia.org/wiki/Freshwater freshwater] on Earth, supporting one third of the world's [[population]].  Many glaciers store water during one [[season]] and release it later as meltwater, a water source that is especially important for [[plants]], [[animals]] and [[human]] uses when other sources may be scant.

Because glacial mass is affected by long-term [[climate]] changes, e.g., precipitation, mean temperature, and cloud cover, glacial mass [[changes]] are considered among the most [[sensitive]] indicators of [http://en.wikipedia.org/wiki/Climate_change climate change] and are a major source of variations in [http://en.wikipedia.org/wiki/Current_sea_level_rise sea level].[http://en.wikipedia.org/wiki/Glacier]

Because glacial mass is affected by long-term [[climate]] changes, e.g., precipitation, mean temperature, and cloud cover, glacial mass [[changes]] are considered among the most [[sensitive]] indicators of [https://en.wikipedia.org/wiki/Climate_change climate change] and are a major source of variations in [https://en.wikipedia.org/wiki/Current_sea_level_rise sea level].[https://en.wikipedia.org/wiki/Glacier]

[[Category: Earth Science]]

[[Category: Earth Science]]