Waterfall

Question 1

Where do waterfalls form

Answer 1

Upper course

Question 2

What are waterfalls

Answer 2

A steep or vertical section of the river where water flows over the edge of a steep high cliff in the hills and mountains, and falls into a plunge pool below, formed in the upper course

Question 3

1 two layers

Answer 3

A layer of hard resilient rock (basalt) lies on top of soft less resilient rock (chalk)

Question 4

2 what happens when river flows from rocks (erosion and what is formed)

Answer 4

As the river flows from the hard to the soft rock, the softer rock is eroded mores easily and a STEP is formed where the two rocks meet

Question 5

3 what happens the water flow after a step is formed

Answer 5

This causes the water to flow vertically losing its contact with the bed, increasing the speed which increases the erosion of the soft rock

Question 6

4 over time what processes lead to what erosion lead to what being formed

Answer 6

Overtime the processes of HYDRAULIC ACTION and ABRASION lead to vertical erosion which deepens and widens the base of the waterfall creating a PLUNGE POOL

Question 7

5 what happens to the softer rock

Answer 7

This cause the softer rock to be eroded more quickly undercutting the hard rock laterally which creates a NOTCH that grows in size. The OVERHANG of hard rock eventually becomes unstable and collapses into the plunge pool

Question 8

6 what does the excess material provide and where does the waterfall move

Answer 8

This collapse of hard rock provides more material for the process of abrasion. The position if the waterfall migrates upstream (retreats) leaving behind a steep sided GORGE