 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Glacier cave" – news ·newspapers ·books ·scholar ·JSTOR(October 2023) (Learn how and when to remove this message) |
 | This article includes a list ofgeneral references, butit lacks sufficient correspondinginline citations. Please help toimprove this article byintroducing more precise citations.(December 2013) (Learn how and when to remove this message) |
Aglacier cave is acave formed within theice of aglacier. Glacier caves are often calledice caves, but the latter term is properly used to describe bedrock caves that contain year-round ice.[1]
Glacier caves form in the bottom edge of glacier ice. Although with low permeability in glacier ice, 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 amoulin 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 bysolifluction. The water flow must dissipate enough heat to keep the glacier ice refreezing in polar areas. Air movement can then assist enlargement through melting in summer andsublimation in winter. Meltwater reaches the bottom of the ice sheet through basement melting caused by geothermal heating and the melting of the ice surface under the pressure of the weight of the ice above. The downwardinfiltration are made of flow of melting superice in glacial systems.
Some glacier caves are formed bygeothermal heat from volcanic vents or hotsprings beneath the ice. Magma from volcanic activities reaches the bottom of glaciers and thus creates caves and channels to further form caves. An extreme example is theKverkfjöll glacier cave in theVatnajökull glacier inIceland, measured in the 1980s at 2.8 kilometres (1.7 mi) long with a vertical range of 525 metres (1,722 ft).
Many glacier caves are relatively unstable due to heat transportation andglacial motion, and are subject to localized or complete collapse, as well as elimination byglacial retreat. An example of the dynamic nature of glacier caves is the formerParadise Ice Caves, located onMount Rainier in theUnited States. Known since the early 1900s, the caves were thought to have disappeared altogether in the mid-1940s, yet in 1978 cavers measured 13.25 kilometres (8.23 mi) 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 byglaciologists to gain access to the interior of glaciers. The study of glacier caves themselves is sometimes called "glaciospeleology".
Media related toGlacier cave at Wikimedia Commons