Dead Ice (transparent area) found in south of Hohe Geige; a mountain in Austria.

Dead ice is the ice on a part of a glacier or ice sheet that is no longer moving.[1] As dead ice melts in its original position, it leaves behind a hummocky terrain known as dead-ice moraine. Dead-ice moraine is produced by the accumulation of sediments carried by glaciers that have been left behind from ice melting. Such features include kettle holes.[2][3] Landscapes forming Veiki moraines in northern Sweden and Canada have been attributed to the errosion of extensive bodies of till-covered dead ice.[4]

Formation

Dead ice is created when a glacier or ice sheet experiences an increase in melting and accumulates debris from various sediment sources. The debris seeps into the ice, effectively covering the surface area.[5] This leads to the affected area becoming mixed with different types of debris, ultimately slowing the glacier's melting rate.[3][5] This process continues over and over, creating layers of ice and debris, until it forms dead ice. Dead ice most occur commonly on surge-type glaciers; glaciers that have ceased moving.[5] It can also be found in any stagnant or debris-filled glacier landforms.[6]

Melting

There are two types of ways dead ice can melt: backwasting and downwasting. Backwasting is when the dead ice melts parallel to an ice-wall or ice-cored slope. Backwasting is more likely to occur when an area is fully ice-cored.[6] Downwasting is when dead ice melts at its top and bottom surfaces. Both dead ice melting rates depend on the climate condition of the area it is in; however downwasting has several other factors that contribute to its process.[5] Another factor that effects both melting rates is the type of debris that covers the dead-ice.[5]

References

  1. ↑ "Dead ice". Cryosphere Glossary. National Snow & Ice Data Center. Retrieved 5 September 2021.
  2. ↑ Whittow, John (1984). Dictionary of Physical Geography. London: Penguin, p. 133. ISBN 0-14-051094-X.
  3. 1 2 Bluemle, John P. "Buried Glaciers and Dead-Ice Moraine". North Dakota Notes. North Dakota Geological Survey. Retrieved 7 September 2021.
  4. ↑ Lagerbäck, Robert (1988). "The Veiki moraines in northern Sweden - widespread evidence of an Early Weichselian deglaciation". Boreas. 17 (4): 469–486.
  5. 1 2 3 4 5 Schomacker, Anders (2008–2011). "What controls dead-ice melting under different climate conditions? A discussion". Earth-Science Reviews. 90 (3–4): 103–113. doi:10.1016/j.earscirev.2008.08.003. ISSN 0012-8252.
  6. 1 2 "7 Dead-Ice Environments: A Landsystems Model for a Debris-Charged, Stagnant Lowland Glacier Margin, Kötlujökull", Developments in Quaternary Sciences, Elsevier, vol. 13, pp. 105–126, 2010-01-01, retrieved 2023-11-10


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