Did you know ten percent of the land on Earth comprises glaciers? Well, first let us talk about our topic. Glaciers are massive glacier masses that grow on land when falling snow is compacted into ice over decades. Glaciers are large sheets of ice formed by the compression of snow. The majority of these glaciers were formed during the previous ice age. Glaciers are enormous icebergs that move slowly. On land, glaciers are formed by falling snow that is compacted into ice over many centuries. The influence of gravity causes them to gently descend.
What is a glacier?
Glaciers are formed by falling snow that accumulates over time to form enormous, thicker ice formations. When snow sits in one place long enough to turn to ice, glaciers form. The ability to flow is what distinguishes glaciers. Glaciers run like very slow rivers due to their tremendous mass. Some glaciers are the size of football fields, while others might stretch for hundreds of kilometers.
Today, glaciers take up 10% of land all over the world. The majority are found in polar regions such as Antarctica, Greenland, and Canada’s Arctic. Glaciers are glacier-covered relics from the previous Ice Age when ice covered about 32% of the land and 30% of the oceans.
Most glaciers are located within mountain ranges that exhibit evidence of a significantly larger extent over the last two million years of ice ages, as well as more recent signs of retreat in the last few centuries.
How are glaciers formed?
Have you ever thought of this as once every glacier was just snowflakes? That’s true. Glaciers are vast and strong, but they start as tiny snowflakes. Consider how many snowflakes it takes to form a glacier when the snow melts into ice. Glaciers form when snow remains in the same region year after year, accumulating enough snow to turn into ice. New layers of snow bury and compress the previous layers each year.
This compression causes the snow to re-crystallize, resulting in grains that resemble sugar grains in size and shape. Gradually, the grains get larger and the air gaps between them shrink, causing the snow to consolidate and become denser.
Snow re-crystallizes as a result of the compression, generating grains that resemble sugar grains in size and shape. The snow gradually compacts and densifies as the granules grow larger and the air pockets between them shrink.
After a year, the snow transforms into firn, a stage halfway between snow and glacier ice. It’s about two-thirds the density of water at this point. Larger ice crystals get so compacted over time that any air spaces between them become exceedingly small. Crystals in old glacier ice can grow to be several inches long. This procedure takes more than a hundred years for most glaciers.
Types of glaciers
1. Mountain glaciers
These glaciers form in high alpine areas, frequently flowing from ice fields spanning multiple peaks or mountain ranges. The world’s greatest mountain glaciers can be found in Arctic Canada, Alaska, South America’s Andes, and Asia’s Himalayas.
2. Valley glaciers
Valley glaciers usually originate from mountain glaciers or ice fields and pour down valleys like huge tongues. Valley glaciers can be very lengthy, flowing down past the snow line and reaching sea level in certain cases.
3. Tidewater glaciers
These glaciers flow far and fast enough to join the sea. In most locations, these types of glaciers act as a habitat and breeding ground for seals. This glacier carves many small icebergs. Even though these are not like the Antarctic iceberg; they are still dangerous for sea lanes.
4. Piedmont glaciers
Piedmont glaciers form when steep valley glaciers pour out over comparatively flat plains, forming bulb-like lobes. The Malaspina Glacier in Alaska is the world’s largest piedmont glacier and one of the most notable examples of this type of glacier. Malaspina Glacier spills out of the Seward Ice field and stretches across the coastal plain, covering roughly 3,900 square kilometers.
5. Hanging glaciers
When a major valley glacier system retreats and thins, branch glaciers are sometimes left high above the diminished central glacier surface in smaller valleys. These are referred to as “hanging glaciers.” The empty high valleys are known as hanging valleys when the entire system has melted and vanished.
6. Cirque glaciers
Cirque glaciers get their name from the bowl-like hollows in which they live. They are usually located high on mountain ridges and are wide rather than lengthy.
7. Ice aprons
Small, sharp glaciers cling to the sides of high mountains. They are generally wider than they are long, similar to cirque glaciers. Ice aprons are abundant in the Alps and New Zealand, where the steep inclines they occupy frequently create avalanches.
8. Rock glaciers
Ice and rock combine to form rock glaciers. Although these glaciers have similar shapes and movements to ordinary glaciers, their ice may be restricted to the center of the glacier or merely fill gaps between rocks. When frozen earth spreads downslope, rock glaciers can occur. Avalanches and landslides can also cause them to accumulate ice, snow, and rocks.
If a glacier is small in size, then that is called an ice cap. Miniature ice sheets covering fewer than 50,000 square kilometers are known as ice caps. They are smaller than continental-scale ice sheets and form mostly in polar and sub-polar locations.
10. Ice fields
Ice fields are similar to ice caps, but their flow is controlled by the underlying topography, therefore they are often smaller.
11. Ice streams
Ice streams are enormous ribbon-like glaciers within an ice sheet, surrounded by slower-flowing ice rather than rock outcroppings or mountain ranges. Changes in the volume of water flowing beneath these massive quantities of moving ice, such as the loss of ice shelves at their terminus, can be extremely sensitive. There are numerous ice streams on the Antarctic ice sheet.
12. Ice sheets
Ice sheets are massive continental masses of glacial ice and snow that cover 50,000 square kilometers and can only be found in Antarctica and Greenland (19,305 square miles). In certain regions of Antarctica, the ice sheet is over 4.7 kilometers (3 miles) thick, covering practically all land features save the Transantarctic Mountains, which protrude above the ice.
The Greenland Ice Sheet is another example. Huge ice sheets once covered much of Canada (the Laurentide Ice Sheet) and Scandinavia (the Scandinavian Ice Sheet), but these have since vanished, leaving just a few ice caps and mountain glaciers.
13. Ice shelves
These are formed as a result of ice sheets floating and extending over the sea. They can range from a hundred meters or one kilometer in thickness. You will find tons of these floating around in Antarctica.
When the weight of ice and snow gets too considerable, they start sloping. That is when you know a glacier has formed. A glacier has developed when evidence of flow appears in a perpetual snow area! It’s no longer just ice and snow; it’s a glacier!