1. Waves and Tides

2. Waves are caused by wind dragging on the surface of the water

3. The length of water the wind blows over is called the fetch
The stronger the wind, the longer it blows for.
The longer the fetch, the larger the waves will be. A B

4. Waves break in shallow water
Waves break in shallow water. The water that rushes up the sand is the swash

5. Water that rolls back into the sea is the backwash

6. When the swash is stronger than the backwash, material is added to the beach.

7. If the backwash is stronger than the swash, then the beach is eroded.

8. The Tees – Exe Line River Tees Hard Rock Soft Rock River Exe Hard Rock

9. The rise and fall in water levels are called tides.
High tide
Low tide

10. The moon ( and to a lesser extent the sun) exert a gravitational pull on the sea; they pull the water nearest them upwards – so the water level falls elsewhere.

11. As the moon travels around the Earth, and the Earth around the sun, the combined pull of the moon and sun changes; so the heights of the tides change too.