Question

which is one way that waves erode coastlines?
○ back-and-forth movement loosens sediment and rock.
○ large rocks are picked up and deposited in new areas.
○ continuous impacts build up sediment and rock.
○ loose sediment is picked up and blown to other locations.

Explanation:

To determine how waves erode coastlines, we analyze each option:

• Option 1: Waves move back - and - forth (like in the swash and backwash of waves), which can loosen sediment and rock. This is a valid erosional process as the constant motion of water can dislodge materials from the coastline.
• Option 2: Picking up and depositing large rocks is more related to the transport and deposition of materials (sedimentation) rather than erosion. Erosion is about breaking down or removing materials from the original location, while deposition is placing them elsewhere.
• Option 3: Continuous impacts building up sediment and rock is a description of deposition or accumulation, not erosion. Erosion is the removal of materials, not the building up.
• Option 4: Loose sediment being picked up and blown by wind is a process of wind erosion, not wave erosion. Waves erode through water - related processes, not wind.

Answer:

A. Back - and - forth movement loosens sediment and rock.