Why Glaciers Matter - National Snow and Ice Data Center
Why they matter. Glaciers, slow-moving rivers of ice, have sculpted mountains and carved valleys throughout Earth's history. They continue to flow and shape the landscape in many places today. But glaciers affect much more than the landscape. Glacier melt delivers nutrients into lakes, rivers, and oceans. Those nutrients can drive blooms of ...
Science of Glaciers - National Snow and Ice Data Center
Glaciers move by internal deformation of the ice, and by sliding over the rocks and sediments at the base. The weight of overlying snow, firn, and ice, and the pressure exerted by upstream and downstream ice deforms glacier ice, in a phenomenon known as creep. A glacier may slide on a thin layer of water at its base.
Glacier Quick Facts | National Snow and Ice Data Center
A glacier is an accumulation of ice and snow that slowly flows over land. Alpine glaciers are frozen rivers of ice, slowly flowing under their own weight down mountainsides and into valleys. Ice sheets exist only on Greenland and Antarctica, and they spread out in broad domes in multiple directions. A group of people explore the Perito Moreno ...
Creeping debris in the Greater Caucasus
2024年11月7日 · This glacier-riding debris might result from the erosion of surrounding rocks, whose debris is carried to the glacier’s surface by avalanches of rock and snow. In fact, many glacier surfaces become the sites of ongoing contests between snow …
Glaciers - National Snow and Ice Data Center
A glacier is an accumulation of ice and snow that slowly flows over land. At higher elevations, more snow typically falls than melts, adding to its mass. Eventually, the surplus of built-up ice begins to flow downhill. At lower elevations, there is usually a higher rate of melt or icebergs break off that removes ice mass.
What are glacial lakes? | National Snow and Ice Data Center
2022年2月15日 · A glacial lake is a body of water that originates from a glacier. It typically forms at the foot of a glacier, but may form on, in, or under it. As Earth’s climate warms, the world’s glaciers are shrinking, increasing freshwater outputs to all kinds of glacial lakes. Some communities depend on glacial meltwater for seasonal irrigation or ...
Global Glacier Debris Thickness Estimates and Sub-Debris Melt …
This data set includes spatially distributed estimates of the debris thickness and sub-debris melt enhancement factors for every debris-covered glacier in the Randolph Glacier Inventory Version 6, excluding the ice sheets and Antarctic Periphery.
Quick Facts About Ice Shelves - National Snow and Ice Data Center
While calving or disintegrating ice shelves do not raise ocean levels, the resulting glacier acceleration does, and this poses a potential threat to coastal communities around the globe. Worldwide, more than 100 million people currently live within 1 meter (3.3 feet) of average sea level. According to the United Nations' Ocean Conference held ...
Homepage | National Snow and Ice Data Center
Glaciers are huge masses of ice, snow, rock, sediment, and often liquid water that originate on land and move down slope under the influence of their own weight and gravity. The two main types are continental glaciers (or ice sheets) and alpine glaciers. Ice sheets are masses of glacial land ice extending more than 50,000 square kilometers ...
glacier pothole | National Snow and Ice Data Center
glacier pothole. potholes formed at the bottom of glaciers through erosion caused by sand and gravel in melt-water; melt-water seeps through crevasses in the glaciers, sometimes forming whirpools; at the bottom of the glacier, the water is under very high pressure, leading to erosion of underlying rocks.