153 - Glacier Perito Moreno - Grotte glaciaire - Janvier 2010

A glacier cave is a

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

formed within the

ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...

of a

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

. Glacier caves are often called

ice cave An ice cave is any type of natural cave (most commonly lava tubes or limestone caves) that contains significant amounts of perennial (year-round) ice. At least a portion of the cave must have a temperature below 0 °C (32 °F) all ...

s, but the latter term is properly used to describe bedrock caves that contain year-round ice.

Overview

Cueva excavada en el hielo por aguas termales, Islandia

Most glacier caves are started by water running through or under the glacier. This water often originates on the glacier's surface through melting, entering the ice at a moulin and exiting at the glacier's snout at base level. Heat transfer from the water can cause sufficient melting to create an air-filled cavity, sometimes aided by

solifluction Solifluction is a collective name for gradual processes in which a mass moves down a slope ("mass wasting") related to freeze-thaw activity. This is the standard modern meaning of solifluction, which differs from the original meaning given to it ...

. Air movement can then assist enlargement through melting in summer and sublimation in winter. Some glacier caves are formed by geothermal heat from volcanic vents or hotsprings beneath the ice. An extreme example is the

Kverkfjöll Kverkfjöll (; 1,764 m) is a mountain range situated on the north-eastern border of the glacier Vatnajökull in Iceland. With the glacier Kverkjökull, it is between the Vatnajökull glacier and the Dyngjufjöll mountains. The mountains are act ...

glacier cave in the

Vatnajökull Vatnajökull ( Icelandic pronunciation: , literally "Glacier of Lakes"; sometimes translated as Vatna Glacier in English) is the largest and most voluminous ice cap in Iceland, and the second largest in area in Europe after the Severny Island ice ...

glacier in

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

, measured in the 1980s at long with a vertical range of . Some glacier caves are relatively unstable due to melting and

glacial motion Glacial motion is the motion of glaciers, which can be likened to rivers of ice. It has played an important role in sculpting many landscapes. Most lakes in the world occupy basins scoured out by glaciers. Glacial motion can be fast (up to , ob ...

, and are subject to localized or complete collapse, as well as elimination by

glacial retreat The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use, mountain recreation, animals and plants that depend on glacier-melt, and, in the longer term, the level of the oceans. Deglaciation occu ...

. An example of the dynamic nature of glacier caves is the former

Paradise Ice Caves The Paradise Ice Caves (also known as the Paradise Glacier Caves) were a system of interconnected glacier caves located within Mount Rainier's Paradise Glacier in the United States The United States of America (U.S.A. or USA), commonly k ...

, located on

Mount Rainier Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a s ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. Known since the early 1900s, the caves were thought to have disappeared altogether in the mid-1940s, yet in 1978 cavers measured of passageways in glacier caves there, and it was then considered the longest glacier cave system in the world. The Paradise Ice Caves collapsed and vanished in the 1990s, and the lower lobe of the glacier which once contained the caves has also vanished entirely between 2004 and 2006. Glacier caves may be used by

glaciologist Glaciology (; ) is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice. Glaciology is an interdisciplinary Earth science that integrates geophysics, geology, physical geography, geomorphology, clima ...

s to gain access to the interior of glaciers. The study of glacier caves themselves is sometimes called "glaciospeleology".

Examples

(Washington, USA) Two craters on top of a cone on the volcano's summit contain the world's largest volcanic ice-cave system. *

Perito Moreno Glacier The Perito Moreno Glacier () is a glacier located in Los Glaciares National Park in southwest Santa Cruz Province, Argentina. It is one of the most important tourist attractions in the Argentine Patagonia. The ice formation, in length, is one ...

(Argentina) *

Titlis Titlis is a mountain of the Uri Alps, located on the border between the cantons of Obwalden and Bern. At above sea level, it is the highest summit of the range north of the Susten Pass, between the Bernese Oberland and Central Switzerland. It ...

(Switzerland)

References

External links

The Virtual Cave: Glacier Caves
{{Subterranea Caves Glaciology Glacial landforms

Overview

Examples

See also

Further reading

References

External links