glaciated landscapes 4

Question 1

glacio-fluvial environments

Answer 1

Glacio-fluvial is a term used to describe processes and landforms associated with the action of meltwater streams in post-glacial times.
- Streams are supraglacial (surface), subglacial (below glacier) or proglacial (in front of glacier).
- Meltwater streams are sorted, graded (largest to smallest), stratified, smooth and rounded.

Question 2

outwash plains

Answer 2

These are flat expanses of glacio-fluvial sediment at the glacial snout.
1 - temps rise, glacier melts, snout retreats, streams carry sediment.
2 - pro glacial streams transport and deposit a lot.
3 - Summer: streams have a high discharge and lots of sediment, winter: low discharge.
4 - when summer goes to winter, sediment gets deposited within channel as mid-channel bar, coarse particles deposited first.
5 - Added material to bar cause braided streams as channel subdivides around bar and re-joins.

Question 3

eskers & kames

Answer 3

Eskers: long winding ridges composed of stratified material deposited by streams. Formation: temps rise, glacier melts, river discharge increase so carry more sediment. Streams have lots of sediment as they are under hydrostatic pressure. Deposition occurs in streams when pressure is released as the meltwater emerges from snout. As snow retreats, point of deposition moves back to reveal esker.

Kames: hills of sediment laid down by meltwater found in the centre of the valley floor. Formed: As meltwater streams-marginal lakes, they lose energy as they enter a static body of water so deposit material.

Question 4

kettle holes

Answer 4

Produced by stagnant blocks of dead ice melting slowly. Dead ice is buried by the outwash material. Once dead ice has melted, this overlying sediment forms a depression in the outwash plain which is often filled with water.