Basal sliding
Encyclopedia
Basal sliding is the act of a glacier
sliding over the bed before it due to meltwater
under the ice acting as a lubricant
. This movement very much depends on the temperature of the area, the slope of the glacier, the bed's sediment
size, the amount of meltwater from the glacier, and the glacier's size.
The movement that happens to these glaciers as they slide is that of a jerky motion where any seismic events, especially at the base of glacier, can cause movement. Most movement is found to be caused by pressured meltwater or very small water-saturated sediments underneath the glacier. This gives the glacier a much smoother surface on which to move as opposed to a harsh surface that tends to slow the speed of the sliding. Although meltwater is the most common source of basal sliding, it has been shown that water-saturated sediment can also play up to 90% of the basal movement these glaciers make.
The most activity seen from basal sliding is within thin glaciers that are resting on a steep slope, and this most commonly happens during the summer seasons when the sun melts away some of the exposed glacier. Factors that can slow or stop basal sliding relate to the glacier's composition and also the surrounding environment. Glacier movement is resisted by debris
, whether it is inside the glacier or under the glacier. This can affect the amount of movement that is made by the glacier by a large percentage especially if the slope on which it lies is low. The traction caused by this sediment can halt a steadily moving glacier if it interferes with the underlying sediment or water that was helping to carry it.
Great Lakes were created due to basal movement.
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
sliding over the bed before it due to meltwater
Meltwater
Meltwater is the water released by the melting of snow or ice, including glacial ice and ice shelfs over oceans. Meltwater is often found in the ablation zone of glaciers, where the rate of snow cover is reducing...
under the ice acting as a lubricant
Lubricant
A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat...
. This movement very much depends on the temperature of the area, the slope of the glacier, the bed's sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
size, the amount of meltwater from the glacier, and the glacier's size.
The movement that happens to these glaciers as they slide is that of a jerky motion where any seismic events, especially at the base of glacier, can cause movement. Most movement is found to be caused by pressured meltwater or very small water-saturated sediments underneath the glacier. This gives the glacier a much smoother surface on which to move as opposed to a harsh surface that tends to slow the speed of the sliding. Although meltwater is the most common source of basal sliding, it has been shown that water-saturated sediment can also play up to 90% of the basal movement these glaciers make.
The most activity seen from basal sliding is within thin glaciers that are resting on a steep slope, and this most commonly happens during the summer seasons when the sun melts away some of the exposed glacier. Factors that can slow or stop basal sliding relate to the glacier's composition and also the surrounding environment. Glacier movement is resisted by debris
Debris
Debris is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, in geology, large rock fragments left by a melting glacier etc. The singular form of debris is debris...
, whether it is inside the glacier or under the glacier. This can affect the amount of movement that is made by the glacier by a large percentage especially if the slope on which it lies is low. The traction caused by this sediment can halt a steadily moving glacier if it interferes with the underlying sediment or water that was helping to carry it.
Great Lakes were created due to basal movement.