Unit Five - Weathering and Erosion - Waves

Question 1

What are Waves?

Answer 1

Due to the causation of wind, the up and down motion of water in the ocean/ lake

Question 2

What is the process of waves?

Answer 2

1. As a wave moves towards the shore, ocean becomes shallow
2. Bottom of the wave drags along the ocean floor, causing it to slow.
3. The top continues at the same speed
4. The wave becomes unstable and “breaks”

Question 3

What is a Longshore Current?

Answer 3

1. Def - When the ocean current flows parallel and close to the shore.
2. Cause - Zigzag Wave Pattern

Think of a sediment resting at a beach. The prevailing wind causes a wave to approach the shore at an angle, but it retreats back to the ocean perpendicular to the shore. That sediment is carried along with it and overtime when that zigzag pattern continues, that sediment is deposited to the other side of the shore.

Question 5

What are Groins?

Answer 5

1. Designed to reduce coastal erosion
2. Traps the transported sediment from Long Shore Drift
3. Encourages a wide beach that absorbs wave energy
4. One side of the groin is filled with deposited sediment, creating a wide beach that protects the coastline from erosion

Question 6

How do you know in which direction a wave flows through groynes?

Answer 6

The wave moves towards the side of the groin where there is less buildup of sediments.

Question 7

What are Barrier Islands?

Answer 7

1. A long narrow island
2. Made of buildup of sediment
3. Parallel to the mainland
4. Caused by Longshore Current