Wave action causes erosion primarily by the movement of water which dislodges rocks and suspends sediment. Breaking waves are the key force behind this process.
The Mechanics of Wave Erosion
Here's a breakdown of how waves erode coastlines:
- Suspension of Sediments: When waves break, they churn the water, lifting and carrying away sand, silt, and other loose particles. This suspension of sediment means that the particles are no longer part of the landmass, resulting in erosion.
- Dislodging of Rocks: The immense power of breaking waves can directly impact and dislodge rocks along the coastline. This is particularly effective on cliffs, where the force of the water can weaken the rock structure, leading to collapse.
- Combined Action: According to the reference, these processes may be assisted by ice, chemical weathering, and mechanical abrasion, which may weaken the rocks prior to wave action.
Factors Influencing Wave Erosion
Several factors can amplify the power of wave action and increase the rate of erosion:
- Wave Height and Strength: Larger and stronger waves have a greater capacity to erode the coast because they carry more energy.
- Wave Frequency: A high frequency of waves means more frequent impacts against the coastline, accelerating the erosion process.
- Shoreline Shape: The shape of the coastline can concentrate wave energy at certain points, leading to intensified erosion.
Examples of Wave Erosion
Wave erosion is responsible for many of the unique coastal features that we see:
- Sea Cliffs: The continuous action of waves undercuts the bases of cliffs causing them to collapse over time.
- Arches and Stacks: As waves erode rocks in sea caves, they can carve out arches, and when these arches collapse, sea stacks remain as isolated pillars.
- Beaches: The movement of sediment caused by waves creates and reshapes beaches.
| Wave Action Effect | Description |
|---|---|
| Sediment Suspension | Waves lift and move sand and silt. |
| Rock Dislodgement | Powerful waves break off pieces of rocks. |
| Combined Action | Ice, chemical and mechanical actions may assist. |
In essence, wave erosion is a continuous process powered by the relentless movement of water which can have dramatic effects on our coastlines.
