How are jetties and groins similar in how they manage beach erosion?

Question

1. Both are soft alternative strategies that use barriers to keep sand on the beach.
2. Both are hard structures that keep sand on the beach.
3. Both use beach nourishment to replenish sand on the beach.
4. Both use vegetation to keep sand on the beach.

Answer 1

The correct answer is:

2. Both are hard structures that keep sand on the beach.

Jetties and groins are both built perpendicular to the shoreline in order to trap sand that is transported by waves along the coast. They both function as hard structures that are designed to protect the beach from erosion by stabilizing the shoreline, trapping sand, and preventing it from being carried away by wave action. However, jetties are typically longer than groins and are built to protect harbors or inlets, while groins are built to slow the longshore drift of sand and create more beach space.