Longshore Drift and Coastal Erosion

The video explains how Longshore drift affects beaches, causing sand and pebbles to move along the coast. Waves hitting the beach at an angle, driven by prevailing winds, move particles up and down the beach. This process can change the shape of beaches over time, sometimes leading to their disappearance. To combat this, groins are built to trap material and prevent it from being carried away, although they do not completely stop the movement of sand and pebbles.

What is the length of the beach just north of Abist?

• 3 km

• 2 km

• 1 km

• 4 km

What natural process is responsible for moving sand and pebbles along the coast?

• Sedimentation

• Tidal waves

• Longshore drift

• Erosion

How do waves contribute to Longshore drift?

• By causing erosion

• By hitting the beach directly

• By hitting the beach at an angle

• By creating tides

What role does gravity play in Longshore drift?

• It stops the movement of particles

• It pushes particles up the beach

• It has no effect

• It pulls particles back into the sea

What can be observed in small waves that indicates Longshore drift?

• Pebbles floating

• Sand particles in the water

• Tides rising

• Waves crashing

Why are groins built along the beach?

• To create a barrier for swimmers

• To increase sand deposition

• To enhance wave action

• To trap material and prevent erosion

How many groins have been built to protect the beach?

• 60

• 50

• 40

• 30

What is a limitation of groins in preventing beach erosion?

• They stop all material movement

• They are too expensive

• They don't stop material from moving completely

• They cause more erosion