How do kettle holes form?
Depressions, known as kettles, often pockmark these outwash plains and other areas with glacial deposits. Kettles form when a block of stagnant ice (a serac) detaches from the glacier. Eventually, it becomes wholly or partially buried in sediment and slowly melts, leaving behind a pit.
What is a kettle bog?
Kettlehole bogs are flat peatlands in “kettles,” circular or elliptical depressions, usually deeper than they are wide, formed in morainal, glaciofluvial, or coastal plain deposits by the melting of buried ice blocks.
Why is it called a kettle lake?
Kettles are depressions left behind after partially-buried ice blocks melt. Many are filled with water, and are then called “kettle lakes”. Kettle lake basins were formed as the glaciers receded. While this was happening, a block of ice broke off the glacier, and just sat there.
How do you identify a kettle lake?
Most kettles are circular in shape because melting blocks of ice tend to become rounded; distorted or branching depressions may result from extremely irregular ice masses. … kettles and so are called kettle lakes. If a sandur or valley train contains many kettles, it is referred to as a pitted outwash plain.
How deep are kettle holes?
Kettle-holes are shallow depressions which frequently occur on pro-glacial outwash plains. Most kettle-holes are less than 8 m deep but some attain depths of over 20 m and are up to 2 km wide ( Flint, 1971, p. 212-14). They may occur as isolated pits separated by undisturbed sections of outwash ( Fig.
Where do glacial erratics come from?
Glacial erratics and glacially-transported rocks can be sourced from rocks falling onto the glacier, rocks being picked up and transported at the base of the glacier, and rocks plucked from valley sides.
What does kettle holes mean in geography?
depression
Kettle, also called Kettle Hole, in geology, depression in a glacial outwash drift made by the melting of a detached mass of glacial ice that became wholly or partly buried. When filled with water they are called kettle lakes.
Where are kettle holes formed?
Kettle holes are formed when large blocks of ice calve from the main glacier onto an outwash plain. As the glacier retreats the block of ice is left stranded. The ice then gets surrounded and possibly buried by subsequent meltwater deposits and outwash.
What do erratics look like?
Erratics may be embedded in till or occur on the ground surface and may range in size from pebbles to huge boulders weighing thousands of tons. Erratics composed of unusual and distinctive rock types can be traced to their source of origin and serve as indicators of the direction of glacial movement.
What do erratics tell us?
What do glacial erratics tell us about past ice sheets? The first thing erratics can tell us about past ice sheets is the direction of ice movement. If you find an erratic with a distinctive lithology, you can trace it back to the location where the distinctive bedrock is found.
What surrounds a kettle lake?
The area around Kettle Lakes Provincial Park is covered in a sandy delta laid down by a large river flowing off the ice sheet. Since these huge chunks of ice were buried, they melted slowly, hidden from the sun and insulated from warmer temperatures that were melting the ice sheet itself.
Where does the water in a kettle come from?
A kettle (kettle hole, pothole) is a shallow, sediment-filled body of water formed by retreating glaciers or draining floodwaters. The kettles are formed as a result of blocks of ice calving from glaciers and becoming submerged in the sediment on the outwash plain.
How are kettle holes formed in the Earth?
The kettles are formed as a result of blocks of ice calving from glaciers and becoming submerged in the sediment on the outwash plain. Another source is the sudden drainage of an ice-dammed lake. Kettle holes can form as the result of floods caused by the sudden drainage of an ice-dammed lake.
How are kettles formed in the outwash plain?
Kettle (landform) The kettles are formed as a result of blocks of ice calving from glaciers and becoming submerged in the sediment on the outwash plain. Another source is the sudden drainage of an ice-dammed lake. When the block melts, the hole it leaves behind is a kettle. As the ice melts, ramparts can form around the edge of the kettle hole.
Where are the kettle holes in a glacier?
Glacial outwash is generated when streams of meltwater flow away from the glacier and deposit sediment to form broad outwash plains called sandurs. When the ice blocks melt, kettle holes are left in the sandur.