What does backwash do?

Backwash is the term used to describe the water that flows back toward the ocean after a wave has broken on the shore. This process is essential in shaping coastal landscapes. When waves crash onto the beach, they carry water and sand onto the shore, moving in a landward direction. Following this, backwash occurs as gravity pulls the water back down the slope of the beachface, returning it toward the ocean.

This action is crucial for various coastal processes, including the distribution of sediment along the shore and the overall morphology of the beach. The backwash can transport sediments back into the ocean where they can be re-suspended into the water column or deposited again at a different location. This helps to maintain the dynamic nature of coastal environments, allowing for continuous shaping and reshaping of the beach.

Other choices might involve different coastal processes, but they do not accurately describe the role of backwash. For instance, moving sand landward involves the action of swash, which is the movement of water inland. While wave height can change during specific conditions, backwash primarily pertains to the return flow of water down the beach. The formation of deltas is related to river sediment deposition rather than the action of backwash.