Mannerjäätiköitä

Mannerjäätiköitä refers to ice sheets, which are vast, continuous masses of ice that cover extensive land areas. These are the largest forms of ice on Earth, significantly larger than ice caps or glaciers. Currently, the two major ice sheets are found on Antarctica and Greenland. They are so large that they can be considered distinct geographical features.

Ice sheets are formed over long periods through the accumulation and compaction of snow. As more snow falls, the lower layers are compressed into ice under the immense weight of the overlying snow. This process can take thousands of years. The sheer mass of an ice sheet influences the underlying landmass, often causing isostatic depression, where the land sinks under the weight of the ice.

The dynamics of ice sheets are crucial for understanding global climate and sea-level change. They flow outwards from their thickest central regions due to gravity. This outward movement can result in the formation of outlet glaciers that drain portions of the ice sheet into the ocean. Melting and calving of icebergs from the edges of ice sheets are major contributors to rising sea levels. Studying the behavior and changes in ice sheets, particularly their melt rates, is a key area of glaciological and climate research.