Polar casques: What are they, where are they, how they form and difference with a glacier

Polar caps are extensive ice masses that cover the polar regions of the earth. They are formed by the accumulation of snow throughout thousands or even millions of years. On earth, polar caps are mainly found in two regions: Arctic and Antarctica.

• Arctic: Located in the northern hemisphere, it covers the Arctic Ocean and surrounding areas such as Greenland, Canada, Russia, Norway and Alaska. Although much of the Arctic ice floats in the ocean, Greenland has a huge layer of terrestrial ice.
• Antarctica: Located in the southern hemisphere, it is a continent covered almost entirely by ice. This is the largest polar polar cap, with an area of ​​approximately 14 million square kilometers and a thickness that can exceed 4 kilometers at some points.

The formation of polar caps is a natural process that occurs over thousands or millions of years. It is due to the accumulation of snow in regions where temperatures are extremely low throughout the year, which prevents accumulated snow from being completely melt. This process implies several stages:

1. Snow accumulation: In polar regions, temperatures usually remain below zero for most of the year, allowing snowfall to accumulate instead of melting. Continuous snowfall deposits new layers of snow above the previous ones.
2. Compaction: Over time, accumulated snow layers begin to compress due to the weight of the new layers that are formed on top. The pressure eliminates the air trapped between snow crystals, transforming them into dense ice grains.
3. TRansformation in glacial ice: As the compacted snow continues to accumulate pressure, it becomes glacial ice, a solid and extremely dense material. This ice is the one that constitutes most polar caps.
4. Ice movement: In the regions where the caps are thick enough, the ice begins to flow slowly outward due to the force of gravity. This constant movement forms glaciers that can extend to the ocean.

Polar caps are not only gigantic ice masses, but also perform essential functions for the climate balance and the planet’s ecosystems:

• Global temperature regulation: The ice, because of its white color, has a high albedo, which means that it reflects much of the solar radiation back to space. This effect helps keep the planet cooler. If the caps are reduced, less radiation will be reflected, which will contribute to global warming.
• Fresh water reserve: It is estimated that more than 70% of the fresh water of the earth is trapped in these ice masses.
• Sea level regulation: Polar caps help stabilize sea level by maintaining large amounts of water in solid state. Without them, the accelerated melt, due to climate change, is already contributing to the increase in sea level, which represents a risk for millions of people living in coastal areas.
• Influence in oceanic currents and weather: The melting of polar ice releases cold fresh water in the oceans, which can alter oceanic currents and global climatic patterns.
• Habitat for polar biodiversity: The polar caps and the areas that surround them are home to a rich biodiversity adapted to extreme conditions.

Although the terms “polar cap” and “glacier” are usually used interchangeably, represent different phenomena within the terrestrial ice system. Let’s see what are the main differences:

Polar caps are usually vast, reaching millions of square kilometers and encompassing continental and marine ice layers, while A glacier is a smaller ice mass which flows slowly from high areas to low areas, such as mountains or valleys. Glaciers can be found in any place in the world Where conditions allow ice accumulation and preservation, not necessarily in polar regions.

Although ice in polar caps moves, it does so more generalized and slowly. He Glacier ice is more dynamic And it is in constant motion due to gravity, flowing from high accumulation areas (such as mountains) to lower areas, where they can melt or break in icebergs.

Climate change is having a deep and alarming impact on polar caps, endangering their stability and the essential functions they perform in the balance of the earth’s system.

• The increase in global temperatures is causing Derret of polar caps at an unprecedented pace. The melting of them is one of the main causes of the global sea level increase. When the land ice layers, such as those of Greenland and Antarctica, melt, released water flows to the oceans. This represents a threat to coastal communities, which face more frequent floods, land erosion and massive displacements of people.
• We have mentioned before the polar caps have a high albedo, which means that they reflect much of the solar radiation. As they melt and exposed darker surfaces, such as ocean or earth, they absorb more heat, accelerating global warming in a process known as Positive feedback. We recommend reading this article on the Albedo effect: what is and consequences.
• Finally, the melting of polar caps is affecting the Oceanic and atmospheric currentswhich can alter global climatic patterns.

Polar caps are not exclusive to Earth. In the solar system, there are other planets and celestial bodies that have similar characteristics, although formed by different materials and under very different environmental conditions.

Mars is the planet that most resembles the earth In terms of polar caps, although it presents some differences. Martian polar caps are formed by a mixture of frozen water and solid carbon dioxide, commonly known as “dry ice.”

On Earth, caps are formed exclusively by solid state water. In other planets and moons, they can include carbon dioxide, methane, nitrogen or other compounds, but they are not polar caps as we know it here.

Now that you know what polar caps are, we recommend you read this post with data on the thaw of the poles.

If you want to read more articles similar to Polar casques: What are they, where are they, how they form and difference with a glacierwe recommend that you enter our category of other environment.