Describe the landforms formed by the depositional work of glaciers.
( UPPSC / UPPCS, 2018, 10 Marks)
हिमनदी के निक्षेपण क्रिया द्वारा निर्मित स्थलरूप का वर्णन कीजिए
A glacier or "river of snow" flows where there usually precipitation happens in form of snow. The movement of glaciers starts from the top of the mountain where the snow accumulates and goes in a downward direction due to the force of gravity.
When a glacier reaches the lowest point of the journey, it melts because we know that the temperature increases with the decrease in altitude, and during the journey the glacier brings with it erosive material such as rocks, soil, sand, and gravel. They are deposited in valleys or flat places, due to which various types of deposition landforms are formed.
The following depositional topographies are formed by glaciers:
- Morain or Glacial Till
- outwash ground
- drumlin
- egg topography basket
- Eskers
Moraine or Glacial Till:
- Materials carried by glaciers such as large rocks, small rocks, sand, and silt accumulate in a glacial valley in an unorganized manner; These deposits are called moraines.
Outwash plains:
- When gravel, sand, silt, fine clay, and small eroded material are deposited in a more systematic manner by glacial stream [after thawing] and form an extensive flat alluvial plain, it is called Outwash plains.
Drumlin:
- When glacial debris accumulates in a glacial valley in the form of an "inverted boat" or "oval shape" it is called a drumline.
Egg basket topography:
- When glacier debris in a glacial valley accumulates in the shape of an egg and several drumlins combine to form an "egg basket topography".
Eskers:
- When glacial debris accumulates in a valley in the form of a long curved ridge, it is called an esker.
Try to solve the following questions:
- Describe the "Basket of eggs topography". (UPSC 2016, 150 words, 10 marks)
- Write an explanatory note on the following about Basket of Eggs Topography. (UPPSC 2020)
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