Wave refraction alters the distribution of wave energy along the coastline, leading to varying levels of erosion and deposition.
Here's a breakdown of how it works:
-
Concentration and Dispersion of Wave Energy: Refraction causes waves to bend as they approach the shore due to changes in water depth. This bending either concentrates wave energy on headlands or disperses it in bays.
-
Headland Erosion: Headlands, which are points of land extending into the sea, experience intensified wave action. Due to refraction, waves converge on headlands, leading to higher wave energy and increased erosion. This concentrated erosion can create dramatic coastal features like cliffs, arches, and stacks.
-
Bay Deposition: In contrast, bays receive less wave energy because refraction causes waves to diverge as they enter. The reduced wave energy leads to deposition of sediment, often resulting in the formation of beaches.
-
Longshore Transport Influence: Refraction also influences longshore transport, the movement of sediment along the coastline. The angle at which waves approach the shore, affected by refraction, determines the direction and rate of longshore transport. This can lead to the formation of spits and bars.
In summary:
- Headlands: Wave refraction concentrates wave energy, leading to increased erosion.
- Bays: Wave refraction disperses wave energy, leading to increased deposition.
Consequences:
The effects of wave refraction on the coastline are significant:
- Differential Erosion: The coastline experiences varying rates of erosion, with headlands eroding faster than bays.
- Coastal Landform Development: The distribution of erosion and deposition shapes coastal landforms, creating features like cliffs, beaches, spits, and bars.
- Sediment Distribution: Refraction plays a role in the transport and distribution of sediment along the coast.
