Coastal Systems and Landscapes 2

There are six main ways waves erode the coastline:

1. Abrasion - rock and sediment smash and grind against rocks and cliffs, breaking bits off and smoothing surfaces.

2. Hydraulic action - air in cracks in cliffs is compressed when waves crash in. The pressure exerted by the compressed air break off pieces of rock.

3. Cavitation - as waves recede, the compressed air expands violently, again exerting pressure on the rock, causing pieces to break off.

4. Wave quarrying - energy of a wave as it break against a cliff is enough to detach bits of rock.

5. Solution - soluble rocks get gradually dissolved by the seawater.

6.  Attrition - bits of rock smash against each other and break into smaller bits.

Transportation is the process of eroded material being moved:

The energy provided by waves, tides and currents transports eroded material. There are 4 transportational processes:

1. Traction - very big rocks/boulders are rolled along the sea bed by the force of the water.

2. Saltation - pebbles and gravel are bounced along the sea bed by the force of the water.

3. Suspension - very fine material like silt and clay, is whipped up by turbulence and carried along in the water.

4. Solution - substances that can dissolve, such as limestone, are carried along in the water.

Longshore drift - transportation of sediment along the coastline:

• Swash carries sediment up the beach, parallel to the prevailing wind.
• Backwash carries sediment back down the…