1. Glaciation CGC1P

2. What is a Glacier? Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses Glacier don’t just sit there – they move, very slowly Some are small, like the size of a football field Some can be over 100 kilometres long

4. Glaciers and Ice Ages Presently, glaciers occupy about 10% of the world's total land area Mostly in polar regions like Antarctica and Greenland In the last Ice Age, ice covered about 32% of the earth’s land, and about 30% of the oceans –Most of Canada was covered in ice Glaciers are basically left over from the last Ice Age

6. Ice Ages There have been 8 Ice Ages over the last 750,000 years The warmer period in between are called Interglacial periods The earth has been in an interglacial period for a long time, so we should be due for another ice age in a few thousand years –Human factors like greenhouse gas emissions may delay the onset of another glacial era –Glaciers may provide important global climate change signals

10. How are they formed? Glaciers begin to form when snow remains in the same area year-round, where enough snow accumulates to transform into ice Each year, new layers of snow bury and compress the previous layers Most glaciers take over 100 years to form