1. How are Shorelines Changed by Beach Erosion?

2. Waves
As the waves hit the shore line they transfer their energy to the sand and make it move.
The waves pull the sand back out into the ocean and causes beach erosion.

3. What Causes Waves? Most waves are caused by wind.
Extremely high waves may be caused by earthquakes (tsunamis).

4. Ocean Currents
Ocean currents are the continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind.
Ocean current map will coincide with the wind belts.

5. Long Shore Current
is the movement of sediments, usually sand, along a coast parallel to the shoreline.
sandbars and long shore current

6. Beach Erosion a Costly Problem.

7. How Can We Prevent Beach Erosion?
1. Plant Dune Grass
The roots of the grass will hold onto the sand and help prevent erosion.

8. 2. Jetties
Walls built perpendicular to the shore line (808 & 124 links)
Stops the long shore current from dragging the sand down the shoreline.
But they cause other problems:
Beaches further down shore will erode and no new sand will be added.
Sand bars build up parallel to the shore line

10. 3. Breakwaters
Waves break further away from the shoreline and less sand is carried away.
Sand will build up btn beach and the submerged wall
A lagoon could form

11. 4. Add More Sand
$$$$$$
And where do we get it from? Whose beach should we take it from?
How would that alter the ecosystem in that location?