Glaciers are large bodies of ice that are formed in cold regions. On a mountain, the weight of a heavy mass of ice causes a glacier to flow downwards. As glaciers move, the ice erodes the land surface and carries the broken rocks and soil debris to faraway places.
A glacier is a slowly flowing mass of ice with incredible erosive capabilities. Valley glaciers (alpine glaciers, mountain glaciers) excel at sculpting mountains into jagged ridges, peaks, and deep U-shaped valleys as these highly erosive rivers of ice progress down mountainous slopes. Valley glaciers are currently active in Scandinavia, the Alps, the Himalayas, and in the mountains and volcanoes along the west coasts of North and South America. The amazing, jagged landscape of New Zealand’s Southern Alps is also courtesy of the erosive power of glaciers. The lighting of the signal beacons in the movie The Lord of the Rings – The Return of the King [1] captures this famous landscape.
Continental glaciers (ice sheets, ice caps) are massive sheets of glacial ice that cover landmasses. Continental glaciers are currently eroding deeply into the bedrock of Antarctica and Greenland. The vast ice sheets are incredibly thick and have thus depressed the surface of the land below sea level in many locations. For example, in West Antarctica the maximum ice thickness is 4.36 kilometers (2.71 miles) causing the land surface to become depressed 2.54 kilometers (1.58 miles) below sea level! [2] If all the glacial ice on Antarctica were to melt instantaneously, all that would be visible of Antarctica’s land surface would be large and small landmasses with scattered islands surrounded by the Southern Ocean