In
glaciology, an ice cap is a mass of
ice that covers less than of land area (usually covering a highland area). Larger ice masses covering more than are termed
ice sheets.
Description
Ice caps are not constrained by
topographical features (i.e., they will lie over the top of mountains). By contrast, ice masses of similar size that ''are'' constrained by topographical features are known as
ice fields. The ''dome'' of an ice cap is usually centred on the highest point of a
massif. Ice flows away from this high point (the
ice divide) towards the ice cap's periphery.
[
Ice caps have significant effects on the ]geomorphology
Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or n ...
of the area that they occupy. Plastic moulding, gouging and other glacial erosional features become present upon the glacier's retreat. Many lakes, such as the Great Lakes in North America, as well as numerous valleys have been formed by glacial action over hundreds of thousands of years.
On Earth, there are about of total ice mass. The average temperature of an ice mass ranges between . The core of an ice cap exhibits a constant temperature that ranges between .
Variants
High-latitude regions covered in ice, though strictly not an ice cap (since they exceed the maximum area specified in the definition above), are called polar ice cap
A polar ice cap or polar cap is a high-latitude region of a planet, dwarf planet, or natural satellite that is covered in ice.
There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor a ...
s; the usage of this designation is widespread in the mass media and arguably recognized by experts.
Vatnajökull is an example of an ice cap in Iceland.
Plateau glaciers are glaciers that overlie a generally flat highland area. Usually the ice overflows as hanging glaciers in the lower parts of the edges. An example is Biscayarfonna in Svalbard
Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range ...
.
See also
* Glacier
* Iceberg
An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The ...
* Ice cap climate
* Ice core
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ic ...
* Ice shelf
* List of glaciers in Russia
* Sea ice
Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oce ...
References
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