ANSWERS: 1
  • By scientific convention, ice caps are glacial masses on land that are larger than icefields but smaller than ice sheets--under 50,000 square kilometers. (The "polar ice caps" of popular parlance do not technically meet this definition, and are more accurately called ice sheets and shelves.) Melting is a normal phenomenon on ice caps, but may be increasing in some areas because of climatic shifts.

    Structure

    Ice caps are massive enough to essentially swamp the topography beneath them. Most are contoured like a dome, drained by outlet glaciers that, in many ice caps, plunge to the sea.

    Ablation

    Portions of most ice caps--the ablation zone--experience summer melting of accumulated snow. In the upper portion of the ice cap known as the accumulation zone, fallen snow doesn't melt during the summer.

    Austfonna Example

    The effects of climate shift on ice-cap melting are still being explored. According to a 2009 paper out of the University of Oslo, a major ice cap in the Svalbard archipelago of the European Arctic, Austfonna, has been recently thickening in its interior dome, while its lower drainage glacier fronts have been retreating.

    Volcanic Eruptions

    Some ice caps blanket the summits of volcanoes, and eruptions can cause rapid melting. The 1996 cataclysm of the volcano Gjalp in Iceland occurred beneath that island's largest ice cap, Vatnajokull, and resulted in the formation of a large meltwater lake.

    Shrinking Caps

    The shrinkage of ice caps on Mount Kilimanjaro in East Africa, peaks of the Andes and other temperate highlands may impact water resources in surrounding lowland human communities, a major concern associated with climate change.

    Source:

    National Snow & Ice Data Center - The Cryosphere: Glossary

    Glaciers; M.J. Hambrey, Jürg Alean; 2004

    Copernicus Publications; Geometric Changes and Mass Balance of the Austfonna Ice Cap, Svalbard; G. Moholdt et al; October 2009

    Resource:

    Montana State University Geography 445: Glaciers & Glacial Geology

    Ohio State University: Ice Caps in Africa, Tropical South America ...

    NASA: Grimsvotn Volcano Erupts

Copyright 2018, Wired Ivy, LLC

Answerbag | Terms of Service | Privacy Policy