In
glaciology
Glaciology (; ) is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice.
Glaciology is an interdisciplinary Earth science that integrates geophysics, geology, physical geography, geomorphology, c ...
, 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 sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at La ...
s.
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 ...
of the area that they occupy. Plastic moulding, gouging and other glacial
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...
erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...
al features become present upon the glacier's retreat. Many lakes, such as the Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five 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, no ...
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
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...
.
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 rang ...
.
See also
* Glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...
* 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
An ice cap climate is a polar climate where no mean monthly temperature exceeds . The climate covers areas in or near the high latitudes (65° latitude) to polar regions (70–90° north and south latitude), such as Antarctica, some of the northe ...
* 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 ...
* Ice shelf
An ice shelf is a large floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland, Northern Canada, and the Russian Arctic. The ...
* List of glaciers in Russia
This is a list of glaciers in Russia. It includes glaciers, ice caps and ice domes located in the Russian Federation.
List of glaciers and ice caps
Ice caps
* Academy of Sciences Glacier () – Severnaya Zemlya. Largest single ice formation ...
* 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 o ...
References
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