Glaciers Geography Notes for UPSC - Know Definition, How it is Formed, Types & More!

Glaciers are a large perennial accumulation of water in the form of snow that originates on land and moves down under the influence of gravity. These glaciers are indicators of changes in the climatic patterns. They are usually seen in the snow fields. About 10% of the earth’s surface is covered by glaciers. The Glacier constitutes 2.1% of the total water on earth and 97.2% is in the oceans and inland seas. Glacier is an important geographical term for aspirants appearing in the UPSC IAS Exam. It forms a part of General Studies Paper 1. In this article we shall discuss in detail about glaciers, their types, the glacial landforms and the important glaciers in India.

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What is the Glacier?

Glacier is a bulk of ice moving under its own weight. They are formed due to accumulation of eyes above the Snow Line under extreme cold climates. The estimated number of glaciers across the world ranges between 70000 and 200000. The glaciers grow by gradual transformation of snow into granular snow and turn into Neves and finally into solid glacial lake. Semi compacted snow is transformed into granular snow of denser form. Such granular snow is called firn or Neve.

Glaciers are generally divided into two broad categories: Mountain or Valley glaciers and Continental glaciers.

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How are glaciers formed?

The essential conditions for the formation of Glaciers are-

• Glaciers begin forming in areas where more snow accumulates every year in comparison to the snow that melts.
• After accumulation, the snow begins to compress, become denser and tightly packed. This process of compaction of Snow into glacial firn is called firnification.
• Mean annual temperature should be close to the freezing point.
• Precipitation should produce significant amounts of snow.
• Temperatures throughout the year should not result in loss of previous years snow accumulation.
• When ice grows of about a height of 160 feet, the firn fuse into a huge mass of solid ice. Here the ice begins to move under its own weight.
• The flow of the glacier is higher in the middle than the base.

Types of glaciers

The glaciers can be categorized under the following heads:

Ice Sheets

These are the biggest glaciers on the earth’s surface. They are broad domes with flattened cross section covering thousands of square kilometers. They are hundreds of kilometers in width. They submerge underlying topography. The eyes radiate outward from the center of the eyes sheet. These radiating eyes masses are called eyes sheets. The central part of the ice cap is called the ice cap. The most extensive ice sheets are Antarctic and Greenland ice sheets.

Continental Glaciers

They are called as such because they cover most parts of the continent. Extensive seeds radiate outward from the center and move downslope. At present the biggest Continental glaciers are Antarctic and Greenland Ice sheet. The Antarctic Continental glaciers have an average thickness of 4000m whereas the Greenland Continental Glacier has a thickness of 3000m. Smaller ice caps occur in the Arctic, Canada, Iceland, Norway etc.

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Mountain Glaciers

The eyes moving downslope under the impact of gravity through the valley in the mountains is called Mountain Glacier or Valley Glacier or Alpine Glacier. The length of these glaciers ranges from a few kilometers to 2000 km. They are located above the snow line. The important glaciers of the Himalayan regions are Rupal Glacier, Siachen Glacier, Kedarnath Glacier, Zemu Glacier, Batura Glacier, Hispar Glacier.

Piedmont Glaciers

The glaciers formed due to collisions of several mountain or Valley glaciers at the foothill zone are called piedmont glaciers. Such glaciers are found only in the colder areas and not in the tropical or temperate regions because they melt when they reach the foothill zone. The Malaspina Glacier of Alaska is a typical example of a glacier.

Ice Shelf

It is a floating thick eyes sheet attached to the coast. Since there is no friction of ice with the bed and hence eyes can spread freely. Such glaciers are abundantly found along the Antarctic coast. Eg- Ross ice shelf.

Ice Field

The ice field is comparatively flat and has an extensive mass of ice sheets.

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Cirque Glaciers

The eyes occupying and armatured served in the mountain is called Cirque Glacier.

Niche Glacier

The Niche Glacier represents a small upland mass which rests upon a sloping rock face.

Polar Glaciers

A Polar Glacier is one that is below the freezing temperature throughout its mass for the entire year. A subpolar Glacier contains ice below the freezing temperature except for surface melting in the summer.

Temperate Glaciers

A temperate Glacier is one that is essentially at the melting point. Thus liquid water co-exists with glacier ice. These types of glaciers are found in North America, South America, Europe, Africa, New Zealand and Asia. Some of the Antarctic glaciers and Greenland’s outlet glaciers are temperate glaciers.

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Glacial Landforms

The landforms made by glaciers can be classified under the depositional landforms and the erosional landforms.

Erosional landforms

The major erosional landforms formed by the glaciers are:

• Glacial Valley: These are trough and U-shaped valleys with broad floors and smooth and steep sides. The valleys contain Debris and debris shaped moraines. Very deep Glacial troughs filled with water are called Fiords.
•  Cirque: Cirque are often found at the heads of glacial valleys. These are most common landforms found in glaciated mountains. They are deep long and wide basins with steep concave to vertically dropping high walls at its head as well as sides. A lake of water is often seen within the cirque after the Glacier disappears. Such lakes are termed Cirque lakes or Tarn lakes.
•  Horns and serrated horns: Horns are formed through headward erosion of the Cirque walls. If three or more radiating glaciers cut headword until their Cirques meet, high sharp pointed and steep sided pics called horns are formed.

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Depositional landforms

The major depositional landforms formed by the glaciers are:

Glacial till: The unassorted coarse and fine debris which is dropped by the melting glaciers is called glacial till. Some amount of debris which is small and has to be carried by such melt water streams is washed down and deposited. Such Glaciofluvial deposits are called outwash deposits. The outwash deposits are roughly stratified and assorted.

Moraines: Moraines are long ridges of deposits of glacial till. Terminal moraines are long ridges of debris deposited at the end of the Glacier. Lateral moraines form along the side parallel to the glacial values. The Moraine in the center of the glacial value is called medial moraine. Many glaciers retreating rapidly leave an irregular sheet of till over their valley floors called Ground Moraines.

Eskers: Eskers are reaches made of Sands and gravels which are deposited by glacial melt water flowing through tunnels within and underneath glaciers. Over time the channel or tunnel gets filled up with the sediments and as the ice retreats, the sediments are left behind as a ridge in the landscape.

Drumlins: Drumlins are smooth oval shaped ridge-like features composed mainly of glacial till with some masses of gravel and sand. The long axis of the drumlins are parallel to the direction of ice movement. The drumline facing the Glacier is called the Stoss and is blunter and stepper than the other end called tail.

Significance of Glaciers

The significance of glaciers are as follows:

• Reservoir of Freshwater– About three quarters of earth’s water is stored in glaciers. Therefore Glacier ice is the second largest reservoir of water on the earth and is the largest reservoir of freshwater.
• For the River system- The Glaciers are a major component to feed rivers. For example, the Gangotri Glacier, one of the largest glaciers in the Himalayan mountains, is the source of the Ganga river.
• For the Aquatic animals– Marine aquatic species in the mountainous environment require cold water temperature to survive which is provided by the glaciers. Any changes in the habitat adversely impact the aquatic species and other keystone species. Thus, Glacier provides a favourable habitat for these animals.
• For the People- Glacier provides people with many useful resources. Glacial till provides fertile soil for growing crops. The deposits of sand and gravel are also used to make concrete and asphalt.

Important Glaciers in India

The important glaciers in India are as follows:

Name	State	Mountain
Bhatura Glacier	Jammu and Kashmir	Karakoram mountain range
Khurdopin Glacier	Jammu and Kashmir	Karakoram mountain range
Hispar Glacier	Jammu and Kashmir	Karakoram mountain range
Biafo Glacier	Jammu and Kashmir	Karakoram mountain range
Baltoro Glacier	Jammu and Kashmir	Karakoram mountain range
Chomolungma Glacier	Jammu and Kashmir	Karakoram mountain range
Diamir Glacier	Jammu and Kashmir	Karakoram mountain range
Siachen Glacier	Jammu and Kashmir	Karakoram mountain range
Gangotri Glacier	Uttrakhand	Himalayas
Milam Glacier	Uttrakhand	Trishul peak of Pithoragarh
Pindari Glacier	Uttrakhand	Upper reaches of the Kumaon Himalayas
Zemu Glacier	Sikkim	Eastern Himalayas located on Kanchenjunga peak

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Some Frequently Asked Questions on Biodiversity

Q1.How do glaciers move?
The movement of glaciers is primarily driven by the force of gravity acting on the immense weight of the ice. Several mechanisms contribute to glacier motion. Within the glacier, ice crystals can deform and slide past each other due to pressure and stress. This process, known as plastic flow, allows the glacier to move over time, with the ice behaving like a viscous fluid on a geological timescale. At the glacier's base, a thin layer of meltwater forms due to pressure and friction. This water acts as a lubricant, reducing friction between the glacier and the underlying bedrock or sediment. This basal sliding facilitates the movement of the glacier downslope. Glacial ice moves downhill through a process called creep. Ice particles within the glacier slide and rotate over the bedrock, causing a slow, continuous downslope movement. Periodically, glaciers experience rapid advancements known as surges. 

Q2.How many glaciers are there? 
Around 198,000 glaciers are occupying 726,000 km2 on the planet, and if they all melted, sea levels would rise by approximately 405 mm. Because of their swift response times, glaciers respond to climate change rapidly.

Q3.Are glaciers melting?  
Since the early 1900s, a significant number of glaciers have been melting swiftly on a global scale. The main cause of this problem is human activities. For example, greenhouse gas emissions—especially in the poles—have raised temperatures since the Industrial Revolution. Ninety-five percent of the Arctic's thickest and oldest sea ice has already vanished.

Q4.Why are glaciers important?  
Glaciers are important in shaping and preserving the Earth's environment. These massive ice expanses, prevalent in polar regions and hilly terrains, are extremely important for the planet's natural equilibrium.
To begin with, glaciers serve as natural reservoirs for the Earth, storing a considerable part of the world's freshwater. Glaciers melt when temperatures rise, giving people more access to water supplies.
As they accumulate snow and ice over centuries, they release water gradually, preventing sudden rises in sea levels. This regulation is pivotal for coastal areas, shielding them from the adverse impacts of rapid sea-level changes. Glaciers also serve as archives of Earth's climate history. Layers of ice contain valuable information about past atmospheric conditions, offering scientists critical insights into climate patterns and changes over millennia. Studying glacier ice cores aids in understanding the Earth's climatic evolution and predicting future trends. Additionally, glaciers support diverse ecosystems, fostering unique flora and fauna adapted to harsh, icy environments. These ecosystems contribute to global biodiversity and offer researchers opportunities to study life forms capable of surviving extreme conditions.                                               

UPSC Previous Year questions on Glaciers

Q) Consider the following Pairs : [CSE 2019]

• Glacier: River
• Bandarpunch : Yamuna
• Bara Shigri : Chenab
• Milam : Mandakini
• Siachen : Nubra
• Zemu : Manas

Which of the following pairs given above are correctly matched?

– (a) 1,2 and 4

– (b) 1,3 and 4

– (c) 2 and 5

– (d) 3 and 5

Q) Siachen Glacier is situated to the : [CSE 2020] ]

– (a) East to Aksai Chin

– (b) East of Leh

– (c) North of Gilgit

– (d) North of Nubra Valley

With reference to the water on the planet Earth, consider the following statements: [CSE 2021]

• The amount of water in the rivers and lakes is more than the amount of groundwater.
• The amount of water in polar ice caps and glaciers is more than the amount of groundwater.

Which of the statements given above is/are correct?

– (a) 1 only

– (b) 2 only

– (c) Both 1 and 2

– (d) Neither 1 nor 2

Q) Consider the following statements : [CSE 2010]

On the planet Earth, the fresh water available for use amounts to about less than 1% of the total water found.

Of the total fresh water found on the planet Earth 95% is bound up in polar ice caps and glaciers.

Which of the statements given above is/are correct?

– (a) 1 only

– (b) 2 only

– (c) Both 1 and 2

– (d) Neither 1 nor 2

We hope all your doubts regarding Glaciers are addressed after going through this article.Testbook provides comprehensive notes for different competitive examinations. It has always assured the quality of its product like content pages, live tests, Gk and current affairs, mocks and so on.Ace your UPSC preparation with the Testbook App!

FAQ on Glacier