Continental glacier“Ice blanket”、“Continental ice sheet”。The surface is roughly flat, the middle is slightly thick, and it is in the shape of a shield, with a scale ratio ofMountain glacierLarge.Mainly distributed inantarcticThe mainland and Greenland.Smaller continental ice sheets are often calledIce caporIce field。There are two ice sheets on the earth, namely the Antarctic ice sheet and the Greenland ice sheet, which account for 99% of the total volume of the world's glaciers, of which the Antarctic ice sheet accounts for 90%.About 83% of Greenland is covered by glaciers.
The continental glacier is a large glacier with the largest area and the largest ice thickness.The movement of continental glaciers is basically not affected by the underlying topography.In continental glaciers, the surface of which is as protruding as a shield is called ice shield.The center of the ice shield is a snow covered area, and the edge is a melting area. The glacier moves from the center to the periphery.The other is the glacier with larger surface fluctuation and scale, which is called continental ice sheet.The area of the ice sheet can reach several million square kilometers, and the thickness can reach more than kilometers (the Antarctic ice layer is as thick as 4267 m at most).Quaternary glaciationAt that time, glaciers used to cover North America and Europe extensively.Modern continental glaciers are mainly distributed in polar regions, such as Antarctica, Greenland, Iceland, etc.[1]
Formation of continental glaciers
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When the climate becomes cold and wet or the terrain rises, the perennial snow covered area above the snow line continues to increase. With the increase of ice and snow accumulation, hanging glaciers, cirque glaciers and valley glaciers have successively developed in low-lying areas or valley sources.In the process of continuous growth, each glacier converges into a glacier system, but its internal structure often remains independent, which makes the individual glacier increasingly complex.While valley glaciers have developed into piedmont glaciers, their source ice bodies have also further expanded, spilling over the watershed, so that the upper sources of various glaciers can combine into a unified ice and snow supply area and develop into ice caps.At this time, the glaciers acquired new characteristics and continued to develop until they formed large-scale continental glaciers.[1]
Characteristics and distribution
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It is characterized by its large area, some of which are more than one million square kilometers;Large thickness, some up to several thousand meters, distribution is not limited by underlying terrain.The glacier is shield shaped, the highest in the middle, and flows radially around.The ice layer in the central part is the thickest, and the shape is shield shaped or the surface is covered with a large undulating cake.Continental glaciers are mainly distributed in high latitude areas, such asGreenlandandAntarctic continentGlaciers are the two largest continental glaciers in the world.
The Greenland ice sheet covers an area of more than 1800000 square kilometers, and the measured maximum thickness is about 3350 meters.Smaller continental ice sheets are often called ice caps orIce field。There are two ice sheets on the earth, namelyAntarctic ice sheetandgreenland ice sheet They account for 99% of the total volume of glaciers in the world, of which the Antarctic ice sheet accounts for 90%.About 83% of Greenland is covered by glaciers.
