Q. Which of the following given below is not a depositional landform by glaciers?

[A] Cirque

[B] Moraines

[C] Eskers

[D] Drumlins

Answer: A

Moraines, eskers, drumlins, etc., are some examples of glacial depositional landforms. Although glaciers cover only a small part of the Earth‘s surface today and are constantly retreating due to climate change, the situation was very different in the past. Scientists believe that there were times when nearly the entire surface of the Earth was under ice and snow. The glacial erosional and depositional features visible on the surface of the Earth today serve as proof of the above fact.

Moraine: A moraine is another glacial depositional feature. It consists of accumulated rocks, dirt, and other debris that have been deposited by a glacier. The size of deposits in moraines varies from tiny particles of sand to large boulders. The deposits accumulate on the surface in an unstratified manner without any type of sorting. Moraines are commonly occurring glacial landforms and are often seen in the Himalayan and Alpine mountain regions, Greenland, etc.

Drumlin: Drumlins are depositional landforms formed by a glacier. A drumlin appears in the form of an elongated hill, a shape that can be compared with that of an inverted spoon or an egg buried partly. Drumlins are formed when glaciers move across till or rock debris. They mostly occur in flat lowland areas and extend in a direction parallel to the glacial flow. The drumlins are high and steep at glacier side and tapering and smooth on the lee slope. These landforms are usually found in clusters and often impede the movement of flowing water bodies. Thus, swamps and lake are formed between these landforms. Drumlins are common in Ireland.

Esker: An esker is also a depositional landform formed by glacial action. It exists as a long narrow ridge that wind along a glacial valley or canyon. Due to their peculiar shape, these landforms are often compared to railway embankments. Eskers are usually several kilometers long. They are made up of layers of gravel and sand. Eskers are formed when glacial channels running beneath, within or above a glacier, deposit sediments along their length of flow. Eskers usually form at the terminal region of glaciers where the flow of the glacier is sluggish in nature and is loaded with sediments. The Eiscir Riada is one of the best-known examples of a system of eskers. It runs for a distance of about 200 km covering nearly the entire width of Ireland from Galway to Dublin.

Cirques, U-shaped valleys, hanging valleys, etc, are some examples of erosinal landforms formed by glacial action.

Source: NCERT