In high latitudinal regions or high relief regions, due to less- temperature, process of glaciation takes place. Presence of glaciers in such regions is a common phenomenon. Glacier is such stock of ice, which gradually shifts from its original place on the earth’s surface. In snow – covered regions, glaciers erode the rocks while performing corrasion and attrition and deposit moraines in various forms.
Through these processes, two types of topographies are formed:
1. Erosional topographies,
2. Depositional topographies.
Both these types of topographies have been described in the following form:
1. Erosional Topographies:
(a) U – Shaped valley: U – shaped valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring.
(b) Hanging valley: In the U – shaped major deep valley, its assisting glacier valley appears to be hanging above it.
(c) Cirque: This is an easy – chair – shaped trough formed by the glacier.
(d) Tarn: This is a lake formed by filling up of water in the cirque basin.
(e) Nunatak: Projected mounds in glacial regions are known as nunataks.
(f) Col: This is a traverse path formed by the conjunction of two adjacent cirques.
(g) Crag and Tail: A rocky outcrop with a tapering ridge of glacial deposits extending to one side is known as crag and tail.
(h) Sheep rock: This is a sheep-back shaped rock formed by glacial erosion.
(i) Fiord: These are scraped coasts formed by glaciers due to submergence of valleys.
2. Depositional Topographies:
(a) Moraine: Deposits of pebbles, stones and boulders deposited by glaciers are known as moraines. These get deposited on the sides, back or bottom of the glacier.
(b) Esker: These are long, narrow and wavy ridges formed by the deposit of glacial alluvium.
(c) Kame: These are steep – sloped mounds formed by glacial alluvium.
(d) Kettle: These are troughs formed by melting of glaciers.
(e) Drumlin: Egg – basket shaped structure formed by deposit of boulder bodies is known as drumlin.
(f) Glacial outwash plains: These are fan – shaped plains formed by the spread of debris to distant places due to flow of glacial water.