What happens when a glaciers slowly move down?
Gravity is the cause of glacier motion; the ice slowly flows and deforms (changes) in response to gravity. Rock that falls onto the glacier’s surface is incorporated into the glacier and erodes the bed, forming sediment. The glacier and its load of rock debris flow down-valley.
Where is the glacier flowing the fastest and the slowest?
Like rivers, alpine glaciers flow fastest at the top an center; they are slowest around the sides and bottom.
Which type of glaciers move faster?
thickness: a glacier moves because pressure generated by its own weight causes it to deform and/or slide, consequently, thick glaciers often flow faster than thinner glaciers. This also explains why high velocity glaciers tend to occur in areas of high snowfall.
How does the bottom of a glacier move?
Glaciers move by internal deformation of the ice, and by sliding over the rocks and sediments at the base. Internal deformation occurs when the weight and mass of a glacier causes it to spread out due to gravity. Sliding occurs when the glacier slides on a thin layer of water at the bottom of the glacier.
Do glaciers really move?
Glaciers move by a combination of (1) deformation of the ice itself and (2) motion at the glacier base. At the bottom of the glacier, ice can slide over bedrock or shear subglacial sediments.
What causes crevasses in glaciers?
A crevasse is a crack in the surface of a glacier caused by extensive stress within the ice. For example, extensive stress can be caused by stretching if the glacier is speeding up as it flows down the valley. Crevasses can also be caused by the ice flowing over bumps or steps in the bedrock.
What happens when glaciers retreat?
A retreating glacier loses more water than it gains and so causes sea level to rise. Glaciers have advanced and retreated over large areas of the Northern Hemisphere over geological time, their growth accompanying the cold periods termed glacials (or, more popularly, ice ages).
What happens when glaciers move?
One component of glacier flow is the deformation of the ice itself. This happens at a microscopic scale, as movement occurs within and between individual ice crystals. They can slide past each other, break and deform, and recrystallize to form new grains.
How does glacier movement affect Earth?
A glacier’s weight, combined with its gradual movement, can drastically reshape the landscape over hundreds or even thousands of years. The ice erodes the land surface and carries the broken rocks and soil debris far from their original places, resulting in some interesting glacial landforms.
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