Which geomorphological feature forms when sediment connects a coast to an island?

Which geomorphological feature forms when sediment connects a coast to an island?

• A. Storm surge
• B. Throughflow
• C. Surface stores
• D. Tombolo

Answer: (D)

Sediment deposition by coastal processes can build a land bridge between a coast and a nearby island. When longshore drift moves sand from the mainland toward the island, a spit grows outward. If it extends far enough to meet the island, the sediment connection forms a tombolo, linking the two landmasses. This happens because the island creates a wave shadow that reduces energy in the sheltered area behind it, encouraging sediment to accumulate and extend the spit toward the island. The resulting tombolo may be visible as a narrow strip of land connecting the coast to the island, sometimes at low tide. Other terms describe different ideas: a storm surge is a temporary rise in water level during storms, throughflow is groundwater movement, and surface stores are types of water stored in the landscape. None of these describe the connecting landform that a tombolo represents.

Sediment deposition by coastal processes can build a land bridge between a coast and a nearby island. When longshore drift moves sand from the mainland toward the island, a spit grows outward. If it extends far enough to meet the island, the sediment connection forms a tombolo, linking the two landmasses.

This happens because the island creates a wave shadow that reduces energy in the sheltered area behind it, encouraging sediment to accumulate and extend the spit toward the island. The resulting tombolo may be visible as a narrow strip of land connecting the coast to the island, sometimes at low tide.

Other terms describe different ideas: a storm surge is a temporary rise in water level during storms, throughflow is groundwater movement, and surface stores are types of water stored in the landscape. None of these describe the connecting landform that a tombolo represents.