Objectives

1
Objectives

• By the end of this lesson you should be able to
• explain the difference between swash, backwash
  and longshore drift
• list and explain the formation of landforms
  created by deposition

2
Coastal deposition

• How does the sea create depositional features?

3
Swash and backwash

• How does the sea create depositional features?
• The movement of waves up the beach is known as
  swash. The movement of water back into the sea is
  known as backwash.
• The swash is responsible for washing material up
  onto the shore and depositing it there.

4
What have waves got to do with deposition ?

• Waves usually approach the coastline at an angle.
  
• This causes the swash to run up the beach at an
  angle.
• The backwash will return at right angles to the
  swash, under the influence of gravity.

5
What is Longshore drift?

• Have you ever thrown a ball or stick into the
  sea, only for it to wash up a few metres further
  down the beach?
• This is because the swash and backwash are moving
  at different angles to each other.
• The swash moves material up the beach at a
  certain angle, and the backwash pulls it back
  into the sea at a different angle.
• material is moved along the coastline.
• This movement of material along the coastline is
  known as longshore drift.

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