Glaciers: Fluvioglacial Landforms Flashcards
What are the fluvioglacial landforms?
- meltwater channels
- Kames
- eskers
- outwash plains
- kettle holes
What are meltwater channels?
melting glaciers create powerful meltwater streams formed by higher temperatures. Channels can flow within, in front of and around the glacier. Due to the pressure of the glacier, they are highly erosive. Some followed rivers - that now have misfit streams and some redirected to new channels because of ice - now dry channels. If they lose energy, they deposit sorted material in small islands, creating braided channels. These last a short amount of time, as only during periods of higher temperature, yet eroded landscapes last a long time
What’s an example of a meltwater channel?
One example is Newtondale and Lake Pickering (Yorkshire)
What are kames?
meltwater transports and deposits eroded material on a retreating glacier. Material collects within a depression on top of the glacier. When the glacier melts completely, the material is left on the valley floor. This leaves a mould of (usually fine) material. Kames are sorted, meaning the heaviest load will be deposited first and finer sediment will be on top.
what’s an example of a Kame?
What’s an Eskers?
a long winding ridge of glacial deposition (sand and gravel). An esker is a mould of glacial meltwater channels. Material is deposited when the sub-glacial meltwater channel loses energy. Due to the high hydrostatic pressure, a large load of mound builds up and retains its shape. Deposition occurs during low discharge (winter). They last a medium-long amount of time, due to their size.
What’s an example of an Esker?
One example is Munro Esker, Canada.
What are outwash plains?
when a glacier recedes, a large amount of meltwater is released due to the higher temps melting the ice. The meltwater loses energy as it is under less pressure, so it deposits material in front of the glacier, material is deposited in sorted layers - gravel and rocks first, finer sediment on top. The deposits can create alluvial fan, which is where the meltwater channels separate into smaller, fanned out sections in order to take the quickest route through the deposited material. These don’t last a long time, as it is only sediment and have seasonal variations in discharge.
What’s an example of an outwash plain?
An example of this is Rendu Glacier, Alaska.
What are kettle holes?
as the glacier retreats it may leave large blocks of buried ice. This ice slowly thaws over time and the covering gravel collapses leaving a depression. These depressions are called kettle holes. If the depressions are deep enough to tap the water table, a kettle hole lake forms.
What’s an example of kettle holes?
