As stated in the previous post I know nothing about glaciers so am starting from the absolute beginning. This will help me discover a little about them before discussing them in greater depth and considering how the information could be used in a classroom.
What are glaciers?
- ‘These slow-moving rivers of ice and snow are found in the coldest parts of the world. As glaciers move, they carve through stone and cut valleys into mountains. Glaciers are one of the most powerful erosive forces on Earth.’
- ‘A large body of ice that forms through the tight packing and freezing of snow and then advances and recedes slowly due to its enormous weight and the pull of gravity, changing the shape of the land as it moves.’
- ‘A multi-year surplus accumulation of snowfall in excess of snowmelt on land and resulting in a mass of ice at least 0.1 km2 in area that shows some evidence of movement in response to gravity. A glacier may terminate on land or in water.’
A few facts
- The last Ice Age ended 10,000 years ago.
- In the last ice age, 33% of the earth’s surface was covered by glaciers. This has since reduced to just 10% today (slightly less than the total area of South America).
- A glacier is like a very slow moving river of ice – global glaciers store 75% of the world’s freshwater supply.
- They are found in 47 countries - in polar and high alpine regions.
- They are formed in areas of high snowfall in winter and cool temperatures in summer.
- Glaciers can grow to over 100 miles long.
Where are glaciers located?
Obviously the majority of the world’s glacial ice is found in cold areas such as Antarctica and Greenland. However, they are also found in the majority of continents including Africa, with Mount Kilimanjaro being glaciated. Glaciers require more snow to fall in the winter than can be melted in the summer and as such this is why they are predominantly found above the snow line in mountainous areas (such as Mount Kilimanjaro) and polar regions (Antarctica) (with the snow line varying in different regions of the world). However, due to periods such as the last ice age, evidence of them can also be found in unexpected areas (such as the Yorkshire Dales). Nevertheless, not all cold regions of the world contain vast areas of glaciers, with Siberia experiencing very little glaciation due to not receiving heavy enough snowfall.
| Approximate Worldwide Area Covered by Glaciers (square kilometres) | |||
| Antarctica | | 11,965,000 (without ice shelves and ice rises) | |
| Greenland | | 1,784,000 | |
| Canada | | 200,000 | |
| Central Asia | | 109,000 | |
| Russia | | 82,000 | |
| United States | | 75,000 (including Alaska) | |
| China and Tibet | | 33,000 | |
| South America | | 25,000 | |
| Iceland | | 11,260 | |
| Scandinavia | | 2,909 | |
| Alps | | 2,900 | |
| New Zealand | | 1,159 | |
| Mexico | | 11 | |
| Indonesia | | 7.5 | |
| Africa | | 10 | |
(Not including smaller glaciated polar islands. Table found at http://nsidc.org/glaciers/questions/located.html)
Map showing current world glaciers (shown in white)
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