spits and bars

Question 1

what is longshore drift?

Answer 1

the zigzag movement of sediment along the coastline.

Question 2

what is a spit?

Answer 2

a long, narrow finger of sand or shingle jutting out into the sea from the land.

Question 3

how are spits formed?

Answer 3

1. the prevaling wind blow at an angle to the coastline, waves move up the beach as swash and down the beach as backwash. this transports material along the coast as longshore drift.
2. when the coastline changes direction, longshore drift continues. overtime deposition occurs creating a spit.
3. these spits will continue to grow.
4. a cross wind creates a recurved end.
5. it grows further.
6. the area behind the spit is sheltered and so deposition occurs, a salt marsh may form.

Question 4

what is a bar?

Answer 4

when a spit has grown across a bay trapping a lagoon behind it.

Question 5

how are bars formed?

Answer 5

1. a spit grows across a bay.
2. when it joins two headlands it becomes a bar.
3. a river with a strong current will prevent a bar from forming.

Question 6

how are depositional landforms created along the coast?

Answer 6

1. depositional landforms such as spits and bars form along our coast.
2. spits form when the prevailing wind blows at an angle to our coastline. swash and backwash transport sediment along the coast in a zigzagged movement called longshore drift.
3. at a change in the direction of the coastline, this continues and overtime deposition occurs creating a spit.
4. eventually if this spit grows and joins two headlands, it will become a bar.