upper course

Question 1

what are v shaped valleys?

Answer 1

deep narrow valleys with steep sides that resemble the letter “V”

found in the early stages of a river journey where vertical erosion is dominant

Question 2

how are v shaped valleys formed?

Answer 2

the river erodes the bed(bottom) mire than the sides cutting deep into land vertical erosion

over time weathering weaken the valleys sides causing them to collapse and form the characteristic v shaped valley

Question 3

what are waterfalls?

Answer 3

a vertical drop in the rivers course where water flows over a ledge

common in areas with resistant (hard) rock layers over softer rock.

Question 4

how are waterfalls formed?

Answer 4

1. the river flows over a layer of hard rock sitting above softer rock .
2. the softer rock erodes faster, creating a step
3. as erosion continues the step becomes steeper forming a waterfall
4. the force of the falling water erodes a plunge pool at the base
5. overtime the waterfall retreats upstream leaving a gorge behind

Question 5

what are gorges?

Answer 5

deep narrow valleys with steep sides often formed as waterfalls retreat

Question 6

how are gorges formed?

Answer 6

when a waterfall erodes backward (upstream retreats) it craves out a deep valley

the process continues over thousands of years deepening and extending the gorge

Question 7

what are potholes?

Answer 7

circular holes in the riverbed ranging from small to large

Question 8

how are potholes formed?

Answer 8

fast moving water carries small rocks and pebbles

these get trapped in hollows and swirl around grinding down the through abrasion

over time the hole deepens and widens forming a pothole