Flashcards in Section 1 - Rivers (Erosional And Depositional River Landforms) Deck (15):
What is a meander?
When a river is eroding and depositing material at the same time forming large bends in the river
Explain the process for forming meanders
1. The current is faster on the outside of the bend because the river is deeper so there is less friction to slow the water down, so it has more energy. So more erosion happens on the outside of the bend, forming river cliffs.
2. The current is slower on the inside of the bend because the river is shallower so there is more friction to slow the water down, so it has less energy. So eroded material is deposited on the inside of the bend, forming slip off slopes
What does erosion on the outside bend of a meander cause?
What does deposition on the inside of a meander cause?
Slip off slopes
Where in a meander is there more energy?
The outside of the bend
Why is there more energy on the outside of the bend in a meander?
Because there is less friction because the river channel is deeper
Where is there less energy in a meander?
The inside of the bend
Why is there less energy in the inside of the bend in the meander?
Because there's more friction because the river channel is shallower
Where is the direction of the fastest current?
Hitting the outside of each bend, therefore causing diagonal routes between bends
What happens on the outside of the bend in a meander?
What happens in the inside of a bend in a meander?
What is an ox bow lake?
Where meanders grow over time and get cut off
Explain the process of forming an ox bow lake?
1. Erosion caused the outside bends to get closer...
2. Until there is only a small bit of land between the bends (called the neck)
3. The river breaks through this land, usually during a flood...
4. And the river flows along the shortest course
5. Deposition eventually cuts off the meander, forming an ox bow lake
When does the river usually break through the land in the process of forming an ox bow lake?
During a flood