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Glacial Landforms

Read about the Glacial Landforms UPSC by Unacademey. Learn about the Glacial depositional Features like Moraines, Eskers, and Drumlins.

Introduction

Glaciers are the mass movement of the ice that can change the entire landscape. They can sculpt mountains and carve valleys. Glaciers can move a vast quantity of rocks and sediments.

Initially, one-third of the world earth’s surface was occupied by glaciers. Glaciers keep on floating and change into many features in the world. They turn out into Glacial Landforms.

These glacial landforms are one of the important aspects to understand about the climate changes in the past.

LANDFORMS CREATED BY THE GLACIERS

  • The mass movement of the ice that can change the entire landscape with an average speed of a few meters per day is called glaciers.
  • There are different types of glaciers. They are:
  1. Continental glaciers
  2. Mountain Glaciers
  3. Piedmont glaciers
  4. Valley glaciers
  • Continental Glaciers – The massive continental ice sheet is present in the continental glaciers. It is located in Greenland and Antarctica.
  • Mountain Glaciers – Ice caps are the sheath of the snow and ice on the mountain.
  • Piedmont glaciers – Continuous arrangement of ice sheets is Piedmont glaciers. Usually, it is found in the bottom of Southern Alaska.
  • Valley Glaciers – Found in all such highest mountain ranges of the world. And it is also found in the Himalayas mountains.

Important points:

  • The Karakoram Range is the largest Indian Glacier. In other words Siachen(72 km). Whereas Gangotri in Uttar Pradesh(Himalayas) is 25.5 Km long.`
  • The erosional activity can be performed by the glaciers when it is charged with rock debris.

Glaciers create two types of landforms. Those  Glacial landforms are:

(i) Erosional Landforms

(ii) Depositional Landforms

GLACIAL EROSIONAL LANDFORMS

Due to the accumulation weight of the snow and the ice, the glacial expands. This ice and snow crush, scrape and scour the surfaces of the bedrocks and rocks. It results in the Glacial erosional landforms.

The resulting Glacial erosional Landforms are:

  • Striations
  • Cirques
  • Glacial horns
  • Trim lines
  • U-shaped Valley
  • Roches Mountains
  • Aretes
  • Overdeepenings
  • Hanging valley
  • It starts from the mountain glaciers.
  • In the case of the Corrie hollow basin cut into the mountain ridge.
  • It has a steep-sided slope on three sides. One on the open end of the Cirque.

And the other two are on.

(i) One side and

(ii) On the flat bottom.

  • The Cirque may evolve into a tarn lake when the ice melts.

GLACIAL TROUGH

  • The glacial trough is originally a stream cut valley and is modified by glacial action.
  • Glacial Trough is in U shape, which is considered as the mature stage of valley formation.
  • The erosion activity is uniform in both vertical and horizontal directions. This uniformity is due to heavy mass and slow movement.
  • The U-shaped profile is obtained by the result of a steep-sided and flat bottomed valley.

HANGING VALLEY

  • A hanging valley is formed when smaller tributaries are unable to cut as deeply. The smaller tributes are unable to cut as bigger ones. So they remain hanging at the higher levels of the main valley as discordant tributaries.
  • The valley carved out by the smaller tributaries glacial joins the larger valley. This valley is carved out by the larger glacier.

ARETE

  • It is considered as the spiky, steep-sided, and sharp-tipped land present between the two mountains.

HORN

  • Horn shape is obtained from the glacial activity when it is cut from two sides.

D-FJORD

  • The coast entrance feature is steep-sided narrow. It occurs when two coasts meet.

Fjords are common in some countries like:

(i) Norway,

(ii) Greenland,

(iii) New Zealand

GLACIAL DEPOSITIONAL LANDFORMS

When Glaciers melt, it leaves behind the crushed rock and sand in the later stage. It is commonly known as Glacial Drift. This activity is characteristic of Glacial Depositional landforms.

Some examples of depositional landforms are

  1. Glacial Moraines,
  2. Eskers,
  3. Kames,
  4. Drumlines, and
  5. Ribbed Moraines.

Fluvioglacial Landforms are the result of the sediment deposit. Or it can be formed reshaped by the meltwater.

The resulting glacial depositional landforms include:

  • Outwash Plain
  • Esker
  • Kame Terraces
  • Drumlin
  • Kettle Holes
  • Moraine

OUTWASH PLAIN

  • Glaciers melt at the lowest point and are left behind as stratified deposition materials. The stratified deposit material includes rock debris, clay, sand, gravel, etc.
  • The layer of surface covered by stratified materials is called till plain or outwash plain.

ESKERS

  • In a till, a plain winding ridge of unsorted deposits will run along with the glaciers. The deposits include rock, gravel, and clay.
  • The esker’s features are similar to that of the embankment. So it is often used for making roads.

KAME TERRACES

  • The un-assorted deposits look like a hump in a till plain.
  • It is a broken ridge.

DRUMLIN

  • Drumlin is a boat-shaped inverter deposit
  • The deposit occurs in the till plain.

KETTLE HOLES

  • It occurs when the deposit materials get depressed and form a basin
  • Here the deposits in the till plain get depressed.

MORAINE

  • Moraine consists of rock fragments, gravel, sand, etc., which are carried by the glaciers.

Depending upon the position of the deposit, there are two types of Morine:

(i) Ground Moraine

(ii) End Moraine

Lateral moraines are formed on the side of the glaciers, and medial moraines are present between two tributary glaciers.

Terminal and recessional Moraines are occurring at the terminal points. It built the rocks and debris which is transported from the ice and melts there.

WHY THE HIGHEST MOUNTAINS ARE PRESENT NEAR THE EQUATOR

  • At lower altitudes, ice and glacier coverage is more in a cold climate, and it is more important than the tectonic plates.
  • Glacial erosion is considered to be very strong. As a lot of huge boulders of rock are carried out by glacial ice it is the strongest. It covers the surface. Since the movement of ice is very slow, the outer layers of the surface area are covered by the rocks.
  • Scientists solved the question.
  • The colder climate is very opted for eroding peaks. So the snow starts melting, and the erosion takes place at a lower altitude.
  • The mountains rise 1500 m above the snow line. The attitude of the snow line is mainly based on the climate and latitude, which decide the height.
  • At low latitudes, the snow melts due to high temperatures. The snowline is about 5500m at the equator. The mountain’s height can vary up to 7000m. But the exception is Everest
  • In Canada, the snowline altitude is 1000m, so the mountain is almost around 2.5Km.

 Conclusion

In glacial landforms, glacial erosion landforms occur due to scouring of land surface due to deposition of ice and snow and glacial depositional landforms is the depositions of crushed rocks and sands after the melting of glacial. We have seen about the landforms created by glaciers and different types and glacial landforms.