Glaciers are large sheets of ice that form when snow accumulates over the course of multiple years without fully melting. Glaciers can be quite large. In fact, some glaciers span hundreds of miles in diameter. They also can be more than a mile thick. Glaciers aren’t stationary, but they move at an extremely slow pace. This is where the term “moving at a glacial pace” comes from.
Facts about Glaciers
- Glaciers form when snow and ice gather over long periods of time without melting.
- The snow at the bottom of glaciers is compacted into very dense ice called “blue ice”.
- Glaciers are found near the north and south polar regions, and at high altitudes in other regions.
- Glaciers can be found on other planets, like Mars.
- “Calving” occurs when giant chunks separate from the main glacier and fall into the ocean.
What are Glaciers?
Glaciers are large sheets of ice that form when snow accumulates over the course of multiple years without fully melting. They can be quite large. In fact, some glaciers span hundreds of miles in diameter. They can also be more than a mile thick. Glaciers aren’t stationary, but they move at an extremely slow pace. This is where the term “moving at a glacial pace” comes from.
Why are glaciers blue?
Older snow in glaciers remains buried beneath thick layers of new snow. The immense weight of the upper layers of snow compresses the lower layers of snow and ice. This turns the older snow into a unique type of ice, called “blue ice”. The ice is blue because air bubbles are squeezed out of the ice. As snow continues to pile on the glacier, the layer of blue ice becomes thicker and thicker over the course of many years.
The blue ice that glaciers are made of is exceptionally dense. This is one reason why glaciers cannot melt quickly even if temperatures temporarily rise well above freezing.
Effects on local climates
Once glaciers have formed, they influence the climate of the area. The area that is covered tends to be significantly colder than the surrounding area. This is because the ice reflects sunlight. In some areas covered by glaciers, the temperature never rises above freezing.
Where are Glaciers found?
The climate has to be incredibly cold for glaciers to form. This type of climate is common in the highest reaches of mountain ranges, particularly in mountainous areas near the poles. However, these conditions can also occur in relatively low lying areas that are close to the poles.
The two largest glaciers in the world are the Antarctic ice sheet and Greenland. Both of these glaciers are located near the poles. There also are extremely large ice sheets in the Himalayas, on mountain ranges in Alaska, and in the Alps.
Currently, they cover approximately 10% of the world. However, they used to cover a much larger portion of the Earth. In fact, glaciers covered around 30% of the Earth during the last ice age, which ended around 12,500 years ago. During that time, a massive ice sheet covered much of the northern part of North America, large tracts of Europe, and Asia. The world’s mountain ice sheets were also much larger than they are now, and there were large ice sheets on mountain ranges as far south as central Mexico and the northern portion of South America. The glaciers of the Himalayan Mountains were also far larger than they are today. The Antarctic ice sheet was also much larger than it is now. It extended as far north as the southern part of South America.
Are glaciers found on other planets?
Glaciers aren’t just found on Earth. There are other parts of the solar system that have glaciers. The polar ice sheets on Mars are some of the most notable examples of this. These ice sheets have some similarities to polar ice sheets on Earth.
Geological features formed by Glaciers
Glaciers erode the land underneath them due to their movement and immense weight. There are many features on Earth that have been carved out by glaciers, including lakes and moraines. Some valleys in mountain regions have been carved out by the movement of glaciers. In addition, large amounts of dirt and rock are piled up in front of the moving glacier. If or when they melt, these piles are left behind, and these deposits can be seen in various regions of the United States.
List of Famous Glaciers
- Furtwängler Glacier, Mount Kilimanjaro, Tanzania. Furtwängler is named after Walter Furtwängler, the younger brother of a famous conductor in Germany. He and Siegfried König were the fourth expedition to the top of Kilimanjaro, and the first to go down the glacier on skis.
- Exit Glacier, Kenai Fjords National Park, Alaska. Exit glacier is well known partly because of its accessibility. It is approximately 4 miles in area, and is currently receding.
- Vatnajökull Glacier, Vatnajökull Glacier Park, Iceland. Vatnajökull is the third largest glacier in Europe. The park contains an amazing array of features, including the glacier, small volanoes, wetlands and mountains. Visitors can hike the glacier and even venture into large ice caves.