Which feature consists of sands deposited offshore and parallel to the coast, often forming a barrier to the mainland?

• A. Barrier Islands
• B. Jetties
• C. Breakwater
• D. Bulkheads

Answer: (A)

Barrier islands are sand deposits that lie offshore, running parallel to the coastline and often forming a protective barrier between the sea and the mainland. They come from sediment carried by waves and longshore currents, building into elongated ridges that create back-barrier lagoons or marshes behind them. Their offshore position and parallel orientation help soak up wave energy and storm surge, shielding beaches and inland areas from erosion. In contrast, jetties extend into the water to stabilize navigation channels, breakwaters are structures built to calm harbor waters, and bulkheads are vertical seawalls along the shore; none of these are natural offshore sands forming parallel barriers. This combination—offshore, parallel sands acting as a protective barrier to the coast—defines barrier islands.