Ice cap

An ice cap is a thick layer of ice that forms over land, usually in high areas. In science, called glaciology, it covers less than 50,000 square kilometers, which is about 19,000 square miles. When ice covers more than this area, it is called an ice sheet instead.

Ice caps are important because they tell us about Earth's climate. They grow when temperatures are cold and shrink when it gets warmer. Studying them helps scientists understand how our planet is changing.

These icy areas are found in cold parts of the world, like near the North and South Poles. They play a big role in keeping Earth cool by reflecting sunlight back into space. As ice caps melt, it can affect sea levels and weather patterns around the globe.

Description

Ice caps are big chunks of ice that sit on top of mountains. They usually have a rounded top in the middle of the highest part of a mountain area. Ice moves from this highest point toward the edges of the ice cap.

These ice caps change the land around them. When they melt, they leave behind valleys and lakes, like the Great Lakes in North America. Most of the world's ice is in Antarctica and Greenland.

Formation

Ice caps form when snow falls during cold weather and does not all melt away. Over many years, the snow piles up and turns into thick, packed snow called perennial firn. Eventually, the snow changes into solid ice.

The shape of an ice cap depends on the land it sits on. The lower parts of an ice cap move outward because of the weight of the ice above, following the shape of the ground below.

Global warming

Ice caps show us how the Earth is warming up. When it gets hotter, ice caps melt faster than they can grow back. Scientists use airplanes and satellites to watch how ice caps are changing.

Ice caps get snow on top and lose snow at the bottom. When everything is balanced, they gain and lose snow at the same rate. But now, ice caps are losing more snow than they gain. This can make sea levels rise. Scientists think that if the Earth keeps getting warmer, ice caps will add more water to the oceans than we expected before.

Variants

See also: Polar ice cap and Ice field

Large areas of ice near the poles are called polar ice caps. An example is Vatnajökull in Iceland.

Plateau glaciers cover flat highland areas. The ice flows over the edges. An example is Biscayarfonna in Svalbard.