Glaciers are present on the Earth in the form of ice sheets in the polar regions which are known as continental glaciers but that does not mean glaciers are only present in the polar regions. They are found in all other parts of the world except the continent of Australia. These are great sources of fresh water on earth that are present in the form of dense ice. In this article, we will be talking about this landform. In this, we will learn about the meaning or definition of the glacier, their distribution, benefits, and other related concepts. This article will help you to understand the very important landform of the Earth and helps you in your studies.
Glacier Meaning and Definition
It is a body of dense ice that moves slowly. It is a perennial structure that forms because of the accumulation of recrystallization of ice, snow, rock, sediments, or any other form which originates on land. They exist where the average annual temperature is closer to the freezing point and precipitation in winters have to snow and especially exist in those areas where temperatures of the current year do not affect the snow accumulation of the last whole year. This continuous accumulation of ice leads to the formation of glaciers. These glaciers look like mountains or peaks and also termed sometimes as mount glacier or glacier mountain.
Mendenhall Glacier in Alaska is a type of mountain glacier as well as a temperate glacier which also consists of a glacial lake and glacial caves. Glacier ridge can be seen in various mountain ranges as well.
According to the Oxford Learner Dictionary, “ glacier means a large mass of ice, formed by snow on mountains, that moves very slowly down a valley.”
According to the Cambridge Dictionary, “ glacier means a large mass of ice that moves slowly.”
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Types of Glacier
Glaciers can be majorly divided into two classifications based on geographic locations such as
Tropical Glaciers
The glacier mountain finds in the tropical regions are known as tropical glaciers. For example, glaciers present in India and Pakistan which are tropical countries.
Temperate Glaciers
The glacier mountain or range or sheets present in the temperate regions are known as temperate glaciers. For example, the Fox glacier in Newzealand or Mendenhall glacier in Alaska are considered temperate glaciers.
Other Types of Glacier Mountain are Classified as Under:
Ice Sheets
These are massive thick glaciers that covered most of the planet during the ice age. They are present on the gentle terrain and sometimes they are so thick that they cover the underlying features as well. From a central accumulation zone, these sheets move in all directions outwards. For example, the Antarctic ice sheets.
Ice Shelves
The floating parts of ice sheets are known as ice shelves. For example, there are a lot of such ice shelves in Greenland and Ellesmere Island.
Ice Caps
These are restricted to mountain plateaus and are smaller ice sheets. For example, on Baffin Island the presence of the Penny Ice Cap.
Cirque Glaciers
These are formed inside or near the mountains in a bowl-like depression. Mostly due to avalanches, the ice or snow accumulation occurs here from the surrounding slopes. For example, Lower Curtis glacier in Washington.
Hanging Glacier
They are formed on the walls of the glacial valley and found in the regions where there are steep mountains. For example, in the Alps mountains, they are common.
Tidewater Glacier
These are the glacier rock that finds their ways to reach the oceans and are insensitive to climate change.
Distribution
They are found on all the continents of the earth except Australia. The distribution in different continents and regions of the world is mentioned below in the table:
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Climate
The climate and temperature of the glaciers vary with locations and time.
Somewhere the entire region is under the melting point and sometimes it is only under the melting point in the sole.
In some regions, it can have a combination of both such as the base layer is at the melting point but the upper layer is below the melting point.
The temperature of 0 degrees celsius can be seen in the temperate glaciers.
The temperature of -40 degrees celsius to -60 degrees celsius can be seen in the upper layers of the Antarctic region.
If the temperature reaches up to the pressure melting point, it can lead to glacier erosion.
Vegetation and Wildlife
These regions do have harsh conditions but still provide some favourable conditions for various species.
Animals found here such as bear, snow leopard, wolverine, etc.
Vegetation like algae, fungus, lichens, mosses, mushrooms, liverworts, etc.
Tundra and alpine vegetation are found in temperate regions.
Benefits
They are a great source of fresh water in the form of glacier lake and glacier streams.
They are useful for the production of hydroelectric power.
Glacier peak or mount glacier also serve as tourist attractions and a source of great revenue for the state.
They maintain the ecological balance of the planet.
They maintain global temperature.
Did You Know?
If the entire glaciers or ice sheets of Antarctica melts then the sea level will almost rise by 65m which means London will be submerged underwater along with several other similar places.
Antarctica and Greenland combined hold more than 99% of the glaciers of the Earth.
Glaciers move very slowly. The Kutiah glacier of Pakistan has moved about more than 12km in only 3 months and it is the fastest glacier surge ever recorded.
Lambert - Fisher Glacier present in Antarctica is one of the largest glaciers in the world.
Fox glacier which is present in Newzealand is one of the most accessible glaciers and also the most attractive tourist destination with 1000 tourists daily visits.
Conclusion:
Thus, in this article, we have covered one important landform i.e. glacier. We have learned the meaning and definition of glaciers, their various types along with their distribution around the world. We have seen its various benefits and have learned what will happen to Earth if glaciers melt. These are dense and huge mass of ice sheets that move very slowly and are a great source of freshwater and maintains the global temperature of the planet. These notes will help the students of Class 8 as well as the students of higher classes.
We have read about the glacier and its related concepts. Let us have a look at the FAQs.
FAQs on Glacier
1. What is a glacier and how is it formed?
A glacier is a large, perennial body of dense ice that moves slowly over land. Its formation is a gradual process that occurs in areas where snowfall consistently exceeds snowmelt. The process involves:
- Accumulation: Snow gathers over many years.
- Compaction: The weight of new snow compresses the layers beneath it, squeezing out air.
- Firn Formation: The compressed snow turns into a granular, dense form called firn.
- Glacial Ice: Over time, with continued pressure, the firn recrystallises into solid glacial ice. Once the ice mass is heavy enough, it begins to move under the force of gravity, officially becoming a glacier.
2. What are the main types of glaciers?
Glaciers are broadly classified into two main types based on their size and location:
- Continental Glaciers (Ice Sheets): These are immense masses of ice not confined by valleys, covering large portions of a continent. They flow outwards from a central point. The ice sheets in Antarctica and Greenland are the prime examples.
- Alpine Glaciers (Valley Glaciers): These glaciers originate in high mountain ranges and are confined within valleys, flowing downwards like a river of ice. They are common in ranges like the Himalayas and the Alps.
3. Where are glaciers typically found on Earth?
Glaciers are found on every continent except Australia. They are primarily concentrated in two types of environments:
- Polar Regions: The vast majority of the world's glacial ice is stored in the massive ice sheets covering Antarctica and Greenland.
- High-Altitude Mountains: Glaciers are also prevalent in major mountain ranges around the world, such as the Himalayas in Asia, the Andes in South America, the Alps in Europe, and the Rocky Mountains in North America.
4. Which is the largest glacier in the world, and which is the largest in India?
The largest glacier in the world is the Lambert-Fisher Glacier in Antarctica. It is an enormous ice stream that drains a significant portion of the East Antarctic Ice Sheet. In India, the largest glacier is the Siachen Glacier. It is located in the eastern Karakoram range of the Himalayas and is the longest glacier in the Karakoram region.
5. What is the difference between a glacier and an iceberg?
The fundamental difference between a glacier and an iceberg is their location and origin. A glacier is a mass of ice that forms and exists entirely on land. An iceberg is a large chunk of ice that has broken off, or calved, from the front of a glacier or an ice shelf and is now floating freely in a body of water like an ocean or a lake. Essentially, an iceberg is a displaced piece of a glacier.
6. How do glaciers shape the land?
Glaciers are powerful agents of geomorphic change that sculpt the land through erosion and deposition. As a glacier moves, it grinds and scours the terrain beneath it, a process known as glacial abrasion, and plucks rocks away. This carves out distinctive features like deep, U-shaped valleys, sharp peaks called horns, and bowl-shaped depressions known as cirques. When a glacier melts, it deposits the sediment and rock it carried, creating landforms like moraines (ridges of debris) and outwash plains.
7. Why are glaciers important for the planet and for human life?
Glaciers are critically important to the Earth's systems and human civilisation for several key reasons:
- Freshwater Storage: They act as natural reservoirs, storing approximately 69% of the world's freshwater. The meltwater from glaciers feeds major rivers, providing essential water for drinking, agriculture, and industry for billions of people.
- Climate Regulation: Their bright, white surfaces reflect a significant amount of solar radiation back into space (the albedo effect), which helps to cool the planet and stabilise global temperatures.
- Sea-Level Maintenance: By holding vast amounts of water on land, glaciers play a crucial role in maintaining stable global sea levels.
8. How is climate change affecting the world's glaciers?
Climate change is causing a rapid and widespread melting of glaciers globally, a phenomenon known as glacial retreat. The primary impact is the addition of vast amounts of meltwater into the oceans, which is a major contributor to global sea-level rise. This threatens coastal cities and ecosystems. Furthermore, as glaciers shrink, the long-term reliability of rivers fed by their meltwater is compromised, posing a future risk of water scarcity for communities that depend on them.
