Cold environments - fluvioglacial processes and landforms


Meltwater streams erode the landscappe...

1) when glacial ice melts, water runs out and forms steams of meltwater. warm-based glaciers and retreaing glaciers produce lots of meltwater.

2) surface meltwater filters throgh the glacier (e.g. through crevasses) and flows through tunnels underneath the glacier, beffore running out of the snout of the glacier

3) Meltwater streams cause erosion in the same way as normal rivers - but they can cause more eriosion than riverss of the same size. this is because the pressure of the ice means that meltwater streams flow very quickly - so they can carry lots of material that erodes the landscape.

4) meltwater streams form deep troughs in the landscape called meltwater channels. Because meltwater streams have a lot of erosive power, the meltwater channls they produce are wie and deep. after the glacier has retreated, the deep meltwater channels are left with very shallow streams running through them.

fluvioglacial deposits come from glacial meltwater...

1) glacial meltwater carries a large load of sediment of various sizes (from inside, on top of and underneath the glacier)

2) meltwater streams deposit their load on the valley floor as they flow way from the glacier

3) meltwater streams are often braided - they split into lots of mini streams that cross over each othe. This is because when the meltwater is flowing more slowly (e.g. in winter when the amount of meltwater is lower) it can't carry its load - so it deposits the sediment on the ground, and splits into two streams to get round it



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