What are the Alpine Glaciers?
A glacier that is surrounded by mountains is called an alpine or mountain glacier. They are a persistent body of snow that moves under its weight at a slow pace. Alpine glaciers are a sheet of snow that forms over a cirque or high rock basin. The iceberg’s uppermost layer is brittle, but the ice beneath behaves like a plastic substance flowing gently.
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How Do the Alpine Glaciers Form?
The glacier usually forms in a cirque or high rock basin where snow accumulates throughout the year. The most amazing fact about this glacier is that the rate of accumulation at the upper surface balances the rate of evaporation and melting at the lower end.
The glacier begins to occupy a sloping valley situated in between the creeks or steep rock walls. Following that, the accumulation of snow occurs at the upper part of the bowl-shaped depression called a cirque.
The glacial ice starts flowing downwards, slowly abrading and plucking the bedrock. The accumulation of snow that is compacting and recrystallizing is called firn.
The flow then accelerates across the steep rock where the deep crevasses or gaping fractures mark the icefall. The lower part of the glacier denotes ablation. As the ice thins, it evaporates and melts, thereby losing its plasticity. There are chances of developing fissures, as the glacier tries depositing debris at the terminus when it melts.
Various Types of the Alpine Glaciers
Glaciers are mainly classified according to their formation. The two main types are the Alpine and the Continental glacier, but there are other types too.
Mountain glacier: Glaciers formed in the high mountainous regions, and flow out of the icefield. They are found in Alaska, Arctic, Canada, Andes, and Himalaya.
Valley glacier: These types of glaciers originate from mountains and then spill across the valleys like a giant tongue. They flow down and touch the sea level.
Tidewater glacier: These are valley glaciers that reach the sea, and they provide breeding habitat for seal. These glaciers are the ones that form small icebergs.
Piedmont glacier: When the steep valley glaciers spill into flat plains, then a piedmont glacier occurs.
Hanging glacier: When the major valley glacier thins out, that becomes hanging glacier.
Cirque glacier: Bowl like hollow structures are called cirque glaciers. They are formed inside the mountains and tend to move towards the valley.
Ice Aprons: Small steep glaciers clinging to the high mountains are called ice aprons. They are an accumulation of ice masses and snow that stick towards the topography of the glacierized basin. They are found above the line of equilibrium.
Rock Glaciers: They are a combination of ice and rocks, but their movements are like regular glaciers. They may extend from outward and then downslope in the tallus cones, or terminal moraines of glaciers.
Ice caps: Ice caps are the miniature version of ice sheets covering lesser than 50,000 square kilometers, generally found in the polar and sub-polar regions. They are smaller in dimension compared to the continental scale ice sheets.
Ice fields: Ice fields are almost similar to the ice caps. Their floe is influenced by the topography underneath, and is smaller than the ice caps. These are formed by the massive accumulation of snow through years of compression, freezing that gradually turns into ice.
Ice stream: They are the ribbon-like glacial set with ice stream. The ice streams are bordered by slow-flowing ice, more than the mountains outcropped. The ice stream in Antarctica is filled with ice sheets.
Ice sheet: Ice sheets are found in Antarctica and Greenland, and are enormous masses of snow that expand to 50,000 square kilometers. You will get ice sheets in Greenland, which also covers most of Canada. They are also known as continental or mass or glaciers.
Ice shelves: Ice shelves range from a few hundred meters to over a kilometer in thickness, which surrounds over Antarctica. The occurrence of ice shelves pauses when there are ice sheets on the sea and water. They are generally formed when the ice sheets flow towards the ocean surface or coastline. Ice shelves are usually found in Greenland, Antarctica, Canada, and Russia. They are essential in maintaining the ice sheet’s stability as they perform the role of a buttress.
Where are the Alpine Glaciers Located?
Alpine glaciers are found in the mountains of every continent, except Australia. Gorner glacier in Switzerland and Furtwangler glacier in Tanzania are good examples of Alpine glaciers. Some more examples of Alpine glaciers found across the globe are:
- 99% of land in Antarctica
- Eqi Glacier in Greenland
- Glacier national park in Montana, USA
- Qualccaya ice cap in Peru
- Fox and Franz Joseph, New Zealand
- Pasterze Austria
- Perito Moreno in Argentina and
- Hubbard, Alaska, in the USA
Alpine Glaciers Vs. Continental Glaciers
Alpine glaciers are found in the mountain tops, but continental glaciers are found in masses like Greenland. Alpine glaciers are smaller compared to the continental glaciers.
While alpines are found only in mountaintops, continental glaciers can be found in earth’s poles, regardless of its elevation. Both of the glaciers move and are responsible for erosion. They develop in cold temperatures and below freezing point.
Examples of landforms created by Continental glaciers are – outwash plain, terminal moraine, erratics, drumlins, and eskers. Alpine glaciers are slow-moving rivers of ice that flow from high mountains.
Like the continental ones, they create lands by weathering and deposition. Examples of landforms by Alpine glaciers are arête, cirque, lateral moraines, hanging valley, terminal moraine, and fjords.
Interesting Facts the About Alpine Glaciers
Fact 1: Glaciers cover almost 10 percent of the earth’s land. During the ice age, it covered nearly a third of the total area of the planet.
Fact 2: Part of the Eastern Arctic Circle housed one of the oldest and biggest glaciers in Canada. Still, you will get a remnant of the Laurentide ice sheet covering parts of Canada during the last ice age. One of the oldest glaciers in Canada is present in Barnes Ice Cap in Baffin Island. Some of them are more than 100,000 years old.
Fact 3: Penny Cap of the Auyuittuq National Park in Iqaluit, Canada, is considered the enormous ice mass of Southern Arctic Circle in Canada, covering approximately 6,400 square meters. Researchers study this ice cap continuously as it is critical to understanding the portion of the glacier that would melt due to climate change.
Fact 4: In Antarctica, Lambert Glacier is the world’s largest glacier; it is 270 miles long and 60 miles in breadth, at its most significant part.
Fact 5: If all the ice melted due to global warming, the sea level would have been 230 feet.
Fact 6: The two types of glaciers are the Alpine and Continental glaciers. Alpine glaciers flow from mountains and continue with the valleys. The Continental glaciers form horizontal sheets and are unaffected by any topography that comes on their way. But, they will tend to flatten anything that surfaces on their way.
Fact 7: Glaciers are present almost everywhere, excluding Australia. Maximum glaciers are found towards the Arctic and the Antarctic Circle, and of course, a few in Greenland. Very few could be found in the provinces of Mexico.
Fact 8: You can mold the glacial ice crystals to the size of a baseball.
Fact 9: The ice generally absorbs all other colors of the spectrum except blue. So, you will see that glaciers reflect mainly the blue color.