What is the process of basal sliding?
Basal sliding is the act of a glacier sliding over the bed due to meltwater under the ice acting as a lubricant. 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.
What is basal sliding quizlet?
Basal Slip. a mechanism of glacial movement in which the ice mass slides over the surface below. cirque. steep sided, half bowl shaped recess at the head of the glacier. continental glacier.
How does basal sliding Help glaciers move?
Basal sliding Glaciers can slide because ice melts under pressure, resulting in a film of water at the ice-bed interface. If water pressures become high enough, cavities can form at the ice-bed interface, causing sliding with bed separation. This reduces basal friction and allows faster ice flow.
What is a internal plastic flow?
internal plastic flow the. process by which glaciers flow. slowly as grains of ice deform. under pressure and slide over. each other.
What is rotational slip in geography?
Rotational Slip – glacial ice moving in a circular motion. As a glacier gets heavier, it begins to move downhill. Fed from the top, the glacier moves out of the hollow in a semi-circular motion, as illustrated above. This is called rotational slip.
How are crevasses created?
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 is basal slip in a glacier?
basal slip: when a thin layer of water builds up at the ice-rock interface and the reduction in friction enables the ice to slide forward. For instance, basal sliding is more efficient as a process if water is present at the base of a glacier and lubricates the ice/rock interface.
What is the difference between basal slip and plastic flow?
Plastic flow involves the entire ice mass slipping along the ground, whereas basal slip involves movement within the ice. Plastic flow occurs in the deeper parts of the ice mass, whereas basal slip occurs at the base of the glacier only.
What is the difference between basal sliding and plastic flow?
What is plastic or internal sliding?
Their movement is typically a combination of processes, but the most common process is internal plastic deformation, or internal flow, which involves the slippage of ice layers within the glacier. With this action, the glacier moves as if it is being spread like a deck of cards.
What does basal sliding on a glacier mean?
Basal sliding. 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.
Which is the most common cause of basal sliding?
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,…
Which is ice sheet cannot move by basal sliding?
In contrast, cold based ice sheets such as Antartica cannot move by basal sliding as temperatures at the base of the ice sheet are well below pressure melting point and so melting is inhibited. Need help with Geography? One to one online tuition can be a great way to brush up on your Geography knowledge.