Ice is a powerful force that shapes the landscape through weathering, erosion, transportation, and deposition of rock material. Freeze-thaw weathering causes cracks in bedrock to enlarge when water freezes and expands. Glacial erosion occurs primarily through plucking, where blocks of rock are torn away from fractures, and abrasion, where rock fragments scrape and gouge the landscape. Rock material is transported and later deposited as moraines when glaciers melt, forming lateral, medial, terminal, and recessional moraines along the sides and at the terminus of the glacier.

1. Key idea: ice is a powerful force in shaping the land as a result of weathering, erosion, transport and deposition

3. Freeze thaw weathering Freeze-thaw is when meltwater or rain gets into cracks in the bed rock, usually the backwall. At night the water freezes, expands and causes the crack to get larger. Eventually the rock will break away

4. Erosion – where rocks are broken down and moved away by ice eg. plucking + abrasion. Weathering - where rocks are broken down ‘in situ’ but are not moved away by ice, water or wind. eg. frost shattering. What is the difference between erosion and weathering ?

6. Abrasion is when rock fragments which have frozen to the base and the back of the glacier scrape the bed rock as the ice moves. Smaller rock particles have a sandpaper effect on the rocks over which the ice passes while the sharp edges of large rocks make deep grooves called striations

7. Direction of flow Crevasses