Rock glacier

Rock glacier

Rock glaciers are distinctive geomorphological landforms of blocky detritus which may extend outward and downslope from talus cones or from glaciers or the terminal moraines of glaciers. Their growth and formation is subject to some debate, with three main theories in prominence:

* They originated from cirque glaciers and contain a glacial ice core or interstitial ice between the rocks which causes the formation to move downslope;

* A permafrost origin, which implies that the features are related to permafrost action rather than glacial action;

* A mass wasting or landslide origin which does not require the presence of ice and suggests a sudden "catastrophic" origin with little subsequent movement.

Rock glaciers may move or "creep" at a very slow rate in part dependent on the amount of ice present.

Possible Martian rock glacier features have been identified by the Mars Orbiter spacecraft.

References

* [http://pubs.usgs.gov/of/2004/1216/glaciertypes/glaciertypes.html USGS Glossary of Glacier Terminology]
* [http://www.agu.org/pubs/sample_articles/cr/2002JE001864/3.shtml AGU - Terrestrial Models of Rock Glacier and Protalus Lobe Formation]
* [http://www.agu.org/pubs/crossref/2003/2002JE001864.shtml "Rock glaciers and protalus landforms: Analogous forms and ice sources on Earth and Mars"] Journal of Geophysical Research V. 108, NO. E4, 8032, 2003
* [http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17847 Earth Observatory image and explanation of a rock glacier on Sourdough Peak, Alaska]
*H. Hausmann, K. Krainer, E. Brückl, W. Mostler. 2007. Internal Structure and Ice Content of Reichenkar Rock Glacier (Stubai Alps, Austria) Assessed by Geophysical Investigations. Permafrost and Periglacial Processes 18: 351-367. DOI: 10.1002/ppp.60


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