A glacier is a large and slow-moving river of ice that forms where the accumulation of snow exceeds its melting rate. Glaciers are not necessarily at high altitudes – intense summertime melting can result in fluctuating rates of growth, even at altitudes as low as 2000 meters.
Approximately 10 percent of the Earth is covered by glaciers. In comparison, arctic regions hold about 80 percent of the Earth’s freshwater (and just about all of it is locked up in ice and snow), while oceans have just 1 percent.
We hope this helps you with your schoolwork or even just to become a glacier king of knowledge.
- Types of Glaciers
- Frequently Asked Questions
- Interesting facts about glaciers
Types of Glaciers
This type of surface ice formation is found in mountain ranges. Moving in and down toward valleys, Alpine ice formations initially form on top of the sides of mountains. These types of ice formations are found worldwide, from North and South America to Africa, Europe, Antarctica, and Asia.
In fact, Alpine ice formations are only absent from the continent of Australia. Some examples of these formations include the Grand Aletsch, Rhone, and Kander Neve (Kanderfirn) glaciers in the Swiss Alps.
Other examples of these formations include those on Washington state’s Mount Rainier (United States). This mountain is 14,410 feet, or 4,393 meters, and is home to some 26 different glaciers. Nearby Mount Baker is 10,778 feet tall (3,285 meters) and is home to 10 such formations.
In mountain formations, descending surface ice can cause deep, cauldron-like depressions, or valleys, to form. These valleys are called cirques (French for “circuses”) and have steep concave sides with sharp-dropping upper cliffs.
The solid land ice accumulations in these formations are known as cirque glaciers. These types of land ice formations carve bowl-shaped depressions in the surrounding rock and eventually move further down the mountain or melt, sublimate, or otherwise disappear.
An example of this formation is the Styggebrean (Styggebreen), located in Norway’s Jotunheimen National Park. Over time, a cirque geological formation may fill with snow or water and freeze into ice or become a liquid-water lake. In the case of the latter, it is called a tarn.
Certain land ice formations have shapes that depend on the underlying geological formations and topography found underneath them. These types of land ice formations are called constrained glaciers. These types of formations can take on field, valley, cirque, niche, and other forms.
These types of ice formations also have a flow pattern that is strongly influenced by the surrounding geological conditions. In this way, the formations can have the appearance of river-like, draining, stationary, spilling, and contained regions of ice.
These types of ice formations are often contrasted with what is referred to as unconstrained glaciers — those formations that do not depend as much on the geological structures and topography underneath them to take various forms.
Other examples of this form are piedmont and transection glaciers.
These types of land ice formations are also known as continental ice sheets. This type of ice formation is extremely large in size and, as its name suggests, is large enough to cover an entire continent.
In practice, however, continental ice sheets are masses of land-based ice that are at least 19,000 square miles in area — or 50,000 square kilometers. Once common during the latest Ice Age some 115,000 to c. 12,000 years ago, they only exist now on Antarctica and Greenland.
The Antarctic Ice Sheet is one of the largest glaciers around — it is 18.6 million cubic miles (30 million cubic kilometers) in volume and covers almost 5.4 million square miles (14 million square kilometers). Melting of this much ice would cause a worldwide sea-level rise of over 150 feet.
Not all ice formations have features that are congruous to horizontally-oriented formations that resemble sheets, lakes, or streams. Some of these formations are located on the steeper sides of mountain ranges and originate from a single peak or peaks.
These types of formations are known as hanging ice formations — land-based ice formations that have only partially descended down mountains — and have not yet joined the lower types of ice formations below.
Resting on the side of a mountain, the hanging ice formation can move down by way of an avalanche. Such ice slides can be dangerous and even deadly; an example of this is an avalanche that occurred on Russia’s Kolka Glacier in 2002, an incident that killed over 120 people.
Mountain ice formations develop when ice and snow accumulate at the top of mountain ranges. They can be of various sizes. These formations are another way of referring to alpine glaciers and can be in the form of valley-covering freshwater sheets or spots of ice on mountainsides.
The Storglaciaren (“Grand Glacier”) in northern Sweden is one of the longest-studied mountain glaciers in history, with surveys occurring at least since 1946. These surveys are taken annually and continue to this day.
With a mass-balance research program — one that studies the accumulation and depletion of an ice formation — scientists have found that the Storglaciaren has had a negative accumulation total for 17 years out of the total years to date. Still, the formation is considered to be retreating.
There are types of ice formations that are adjacent to other, larger ice formations. One example is an ice formation that brings ice away from ice caps (themselves ice formations smaller than 31 million square miles, [50 million square kilometers]) and ice sheets that are located inland.
These types of ice formations are called outlet ice formations. These formations begin essentially where ice caps and large sheets of land-based ice end. They are typically found in valleys and draw ice away from the larger formations.
The Helheim Glacier is located in southeastern Greenland and is one of the largest of the country’s outlet ice formations. It has been recorded as moving at about 6.8 miles (11 kilometers) a year; it drains water into nearby fjords to feed the Sermilik fjord area.
Certain ice formations manage to escape some topographical features and form new shapes once they are on the other side. An example of this is the piedmont ice formation, where large ice formations escape a valley (or mountain range) and spills out into a field or basin.
When the ice “spillover” occurs, it forms ripple and bubble-like patterns on the field below. The resulting ice formation can be dozens of miles in length across and can form shapes that intertwine with the soil, rocks, and other geological materials already present.
Alaska’s Malaspina Glacier is an example of such an ice formation. This formation has its origins in the nearby Seward Glacier and is 40 miles (65 kilometers) wide.
Rock ice formations are masses of mountainside-oriented rock, ice, mud, snow, and water that slowly flow downward into valleys and basins at lower altitudes.
There are at least two types of rock ice formations. These include periglacial and glacial rock ice formations.
Periglacial rock ice formations have ice and water that seep into a rock pile (also known as a talus) and freeze over once inside, making a formation that is mixed.
Glacial rock ice formations are the result of rocks sliding onto an already-present ice formation. These types of formations have solid ice cores. Because of evaporation, larger rocks and boulders tend to be left on the surface, with finer materials at lower levels.
Land-bound ice formations are freshwater in composition. They differ from sea ice in that they usually form from rain or ice and remain on the land. Some of these ice formations, however, do not flow into rock. Rather, they flow into the water.
These types of ice formations are called tidewater ice formations. Tidewater ice formations are usually valley ice formations that break away and fall into the ocean.
These formations make icebergs, themselves large aggregations of freshwater ice.
It is common for tidewater ice formations to form in cycles — these cycles, however, can take hundreds of years. In these cycles, there is continuous advancement to the sea for several years and occasional long pauses in advancement and withdrawal periods.
When ice formations are not reliant on topography in their formation or are independent of surrounding underlying geological features, they are considered unconstrained ice formations. These formations include large ice sheets, smaller ice caps, and ice streams.
As mentioned before, Greenland and Antarctica are home to the largest ice sheets in the world. Smaller ice caps are found in Russia, Iceland, Greenland, and Canada. An example of an ice cap is Hofsjokull in Iceland, the third-largest in the country.
Ice streams are unconstrained ice formations that move at relatively high speeds, a little over 3,000 feet (914 meters) a year. They can be as much as 31 miles wide — and are found flowing directly inside much larger ice sheets.
Ice formations that originate on mountains and form into large river-like ice masses are called valley ice formations. Alaska’s Glacier Bay Park has Fraser Glacier, one of the most prominent valley ice formations, located in Alaska’s Saint Elias Mountains.
Valley ice formations are the main drainage outlets for ice caps and other large ice formations.
They tend to form large, deep valleys in themselves, and like other types of ice formations, tend to move and deposit large amounts of rock.
The valleys that are created from these ice formations are “U”-shaped, as faster-moving liquid waters form “V” shaped valleys. At times, more rock can accumulate at the sides of these valley ice formations, chiefly from rockslides.
Frequently Asked Questions
What are glaciers?
They are huge masses of ice and they ‘flow’ just like rivers, but a LOT slower. They certainly don’t form overnight, it takes hundreds of years, where snow has fallen to compress the snow and turn it into ice.
Glaciers are like one big reservoir of freshwater on the planet. In fact, it’s the biggest in the world. Unbelievably they store about 75% of the freshwater in the world. Wow, that’s certainly quite something. We definitely need these glaciers around.
A névé is the name of an area where a glacier has formed. This is normally in bowl-shaped areas between mountains. Snow collects here easily and compresses and compacts due to the weight of more snow falling on top of it.
Glacial ice keeps on filling the névé until eventually a weakening or a gap between the mountains means the ice mass starts to move down a sloped surface.
How Are Glaciers Formed?
Glaciers begin forming in places where snow piles up over a long time. The snow gets so deep that the top layer of snow freezes and turns into ice.
The snow starts to compress under the weight of all the snow above it. As it condenses, it turns into ice and gets harder.
The ice deepens and gets more compact. After a few years, what started out as a fluffy pile of snow is now hard, and thick ice called a glacier.
What is the biggest glacier?
Lambert Glacier is the largest glacier in Antarctica, with an area of around 50 miles (40 km) wide, over 250 miles (400 km) long. It is one of the two largest valley glaciers on the continent.
Its average rate of movement is about 400-800 meters per year which makes it one of the faster-moving glaciers on Earth.
Do glaciers affect people?
They provide drinking water for people living near them. They fertilize land for agriculture in some of the world’s least densely populated areas and sources of water to generate electricity.
Glaciers affect the economy of many towns and villages by providing jobs in agriculture and tourism. They can affect people by providing them with these necessities to sustain life.
Interesting facts about glaciers
Guess how much of the Earth’s total land area glaciers cover? Any guesses? Well, it’s around 10%. Wow. In the last Ice Age, however, they covered 32%. Can you imagine how cold we’d be!
You get Alpine glaciers, which you’ll find on the side of mountains and they move downwards through valleys.
You also get Continental ice sheets that spread themselves out and cover far larger areas.
The world’s largest glacier is Lambert Glacier. It’s in Antarctica, it is 100km wide, 400km long, and 2.5km deep. Whoa, that is absolutely massive.
Sometimes you’ll see that glaciers actually look like they’re blue. Looks pretty awesome. This is because glacial ice is very dense and compact.
The Kutiah Glacier in Pakistan should be in the Guinness World Book of Records for being the glacier with the fastest gush. It moved more than 12km over three months in 1953. It seems like it might have been in a rush to get somewhere.
The Earth’s two ice sheets cover most of Greenland and Antarctica. They make up more than 99% of the world’s glacial ice. Wow!
Imagine this. If the Antarctic ice sheet had to completely melt, people believe that sea levels would rise by 65m. No way! That would mean that London would be lost underwater. What a crazy fact!
This is amazing. Glacial ice can be hundreds and thousands of years old. What this means is that scientists can use them to check out how climate change is doing. By taking out the ice and studying it, they can also find out what the climate was like on Earth thousands of years ago.
Glaciers can be found in 47 countries. Wow, who would have thought that?
The word ‘glacier’ comes from the French language which was derived from the Latin word ‘glacies’ meaning ‘ice.’
A glacier can be the size of a football field to more than 160km!
This is cool. The Antarctic ice sheet is a glacier that’s been around for at least 40 million years! That’s a seriously long time.
How weird is this? Mount Kilimanjaro sits on the equator. But even so, it is still glaciated.
One single glacier ice crystal can grow to be as large as a baseball! No way, one crystal!
It is thought that Alaska has more than 100,000 glaciers, but most of them don’t have a name.
Are you all glacier smart now? Do you have any glacier facts to share with us?