Tessa has a strong interest in geology, geography, and global warming.
What is a Glacier? Why Glaciers Form.
Some quick pointers about glaciers.
- Glaciers form in very cold climates where new snow falling on top of old snow eventually makes the snow underneath compress into ice.
- Glaciers form over a period of a few hundred years, but some glaciers are many thousands of years old.
- Glaciers form on land and are not stagnant – they move.
- Glaiers are twenty five acres or larger. Ten percent of earth is comprised of glaciers.
- Glaciers are found in 47 countries.
Where are Glaciers Found?
While there are glaciers in forty seven countries, 99% of them are located in the Antarctica and the Arctic. Greenland, Iceland, Canada, Russia, and Alaska have part of their land in the Artic.
That said, with the exception of Australia, every continent contains glaciers. For example, Mt Kilimanjaro in Africa is the second highest peak in the world after Mt Everest, and it has glaciers.
About 80% of Greenland is covered by an ice sheet – 660 square miles
Chile in South America has 31,000 glaciers.
Alaska has about a 100,000 glaciers.
There are 24 glaciers in Mexico – on their highest mountain peaks.
The Swiss Alps has more than 1200 glaciers.
Types of Glaciers
Alpine glaciers are formed on mountains and slide downwards. They normally end in a valley or the ocean and are usually found in the Alps in Switzerland.
Continental ice sheets are found on flat ground and spread outwards. Antarctica has the largest ice sheets in the world and comprises 90% of all ice. In size, they are larger than 19,000 square miles. These glaciers are more than 2.5 miles thick and there are mountains underneath them. If they melted, because they contain 90% of the world’s fresh water, the seas would rise by between 230 and 260 feet. This would bury many of the world’s coastal cities.
Piedmont glaciers spread out at the bottom of a steep mountain.
Ice caps are found are bodies of ice that sit on top of a mountain or volcano. They are also known as ice fields.
Cirque glaciers form on the slopes and crests of mountains.
Tidewater glaciers end at sea level.
What a Blue Glacier Looks Like
Why are Some Glaciers Blue?
The more dense a glacier is, the more blue it appears. This is the same reason that large bodies of water appear to be blue. Water cannot absorb the blue from the light spectrum, and so both the ocean and glaciers appear to be blue.
How do Glaciers Move?
There are two ways in which glaciers move. The first is they move from the top of a mountain to the bottom as a result of gravity.
They also move if there is warm water underneath. This process is called basal sliding.
Generally a glacier will move about a yard (one meter) per day. However, there is quite a variation and some can slide over 50 feet per day. The Jakobshaven Glacier in Greenland moves between 70 and 100 feet per day. In 2012, it moved 150 feet per day causing great concern.
Earthquakes measuring up to 6.1 on the Richter scale happen when a glacier moves faster than half a mile a year.
Can We Get Fresh Water From Glaciers?
Increasing droughts together with industrial poisoning of our water by numerous manufacturers and commercial interests, there is less and less potable water available to drink.
As these glaciers contain more water (69%) than all the earth’s rivers and lakes together (.3%) it is a tempting thought that we might be able to ferry water from icebergs to different countries.
As the situation worsens due to global warming, this might be a consideration, and scientists, inventors, and technologists might begin to find ways of doing that.
The elephant in the room is that if the glaciers melt, then all that fresh water will go into the sea.
When Glaciers Calve i.e. When Pieces of Ice Fall Off Into the Sea
Melting Glaciers and Global Warming
Recent research has indicated that warmer water underneath Antarctica is responsible for the ice melting at a rapid rate. As a result certain glaciers have split into two.
In Greenland, the rapid movement of glaciers is evidence of warmer water underneath, and this has resulted in an increasing number of earthquakes. There are also an increasing number of earthquakes in Alaska.
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Scientists believe that 90% of glaciers are currently melting, and that water goes into the sea. This has disastrous effects on two fronts. The first is that it is a source of fresh drinking water that is no longer available to mankind and other species. The second is that it will make the sea less saline, and this will kill off many fish in the sea, plus change the currents.
The U.S. Geological Service has stated that the Antarctic ice sheet is more than 40 million years old, and if it melted, it would raise the sea level by 210 feet internationally.
Alpine glaciers are melting even more rapidly (the Alps and Rocky Mountains), and this means that lakes which are fed by them in spring will eventually dry up. This is not a good thing for humans and animals that depend on these water sources for drinking water
Certain rivers obtain ‘meltwater’ from glaciers when they thaw in spring, and this is particularly so in the Himalayas mountain in India.
If the temperature of the earth keeps increasing, then the glaciers will melt, and this water will go into the sea. The lakes and river will then be dependent on rain water, and if the drought areas increase as weather scientists indicate, then life on earth will eventually die and many species will become extinct including mankind.
The Lambert Glacier in Antarctica measures 62 miles wide, 270 miles long, and is a mile and a half thick. It is the largest glacier in the world.
The Bering Glacier, as a result of its immense weight, is responsible for the stabilization of the Pacific plate which lies underneath the North American plate.
The Malaspina Glacier in Alaska is the largest piedmont glacier in the world.
The Kutiah Glacier in Pakistan set the record for moving the fastest. In 1953, it moved seven and half miles in three months.
The Grasshopper Glacier in Montana has millions of extinct grasshoppers buried inside its ice.
The Taylor Glacier in Alaska is also known as the Blood Falls glacier because it spews out a red liquid in spring.
So What Are Ice Worms?
Ice worms live in glaciers. They look very much like a small earthworm and are about half an inch long. They eat algae and pollen during the summer months and bury themselves deep in the ice during the winter. They then eat the algae and pollen that is frozen in the ice. They move at about ten feet per hour.
Some Glacier Terms
Ice shelves are part of an ice sheet that extend into the water.
Ice streams are part of an ice sheet that are narrow and move faster than the ice sheet.
An Ice Tongue is a long narrow sheet of ice that protrudes into the ocean.
Icebergs are pieces of ice that break of glaciers and float in the sea.
An ice cap is a small glacier that form in the valley of a mountain range.
Surging happens when meltwater underneath the glacier makes the glacier move faster than usual.
Why Glaciers Matter
Glaciers hold most of the world’s fresh water. In the spring and summer, many glaciers partially melt and the melt water flows into rivers and lakes. These rivers and lakes are the source of drinking water for many people and animals. In the winter, as more snow is deposited on the glaciers, more ice is formed.
In 2015, a part of the Larson C ice shelf in Antarctica calved. It measured a hundred miles wide. In 2017, yet another part calved, this time measuring a two and a half thousand square miles. Each time a glacier calves, the water goes into the sea, contributing to rising sea levels.
Should even a partial amount of these glaciers melt, much of the current world will be under water. It is estimated that the meltwater will heighten the sea by 260 feet. Until 2017, scientists believed that while the glaciers would melt due to climate change, they thought it was a slow process. Recent evidence has indicated that a melt can take place very rapidly as this is now happening in Anarctica.
In addition to rising seas, the ocean will become less saline. As all of life in the sea can only exist in a saline environment, fish seaweed, mammals, etc. will all die. This will kill off a substantial food source for humans.
As fresh water is lighter than salt water, the fresh water will sit on top of the sea water This may affect various currents like the Benguela Current and the Gulf Stream, but it is currently not known how.
Glaciers are a vital part of our world. They cannot be replaced once they are gone.
© 2017 Tessa Schlesinger
Tessa Schlesinger (author) on November 10, 2017:
Thank you, Kari. I think the key to changing our perspective about many things is understanding how our world around us works! :)
Kari Poulsen from Ohio on November 10, 2017:
This article really makes me think. Glaciers are much more common than I knew. I do know that they are melting more rapidly in recent years. Thanks for the information. :)