Coastal Processes Flashcards
What is corrasion (abrasion) ?
Bits of rock and sediment transported by the waves smash and grind against rocks and cliffs, breaking bits off and smoothing surfaces.
What is hydraulic action?
Air in cracks in cliffs is compressed when waves crash in. The pressure exerted by the compressed air breaks off rock pieces.
What is cavitation?
As waves recede, the compressed air expands violently, exerting pressure on the rock and causing pieces to break off.
What is wave quarrying?
The energy of a wave as it breaks against a cliff is enough to detach bits of rock.
What is solution (corrosion) ?
Soluble rocks e.g. limestone get gradually dissolved by sea water.
What is attrition?
Bits of rock in the water smash against each other and break into smaller pieces.
What is solution?
Substances that can dissolve are carried along in the water.
What is saltation?
Larger particles e.g. gravel or pebbles are too heavy to be carried in suspension. Instead the force of the water causes them to bounce along the seabed.
What is suspension?
Very fine materials e.g. silt and clay particles, are whipped up by turbulence and carried along in the water. Most eroded material is transported this way.
What is traction?
Very large particles e.g. boulders are pushed along the seabed by the force of the water.
What is longshore drift?
When swash carries sediment up the beach, parallel to prevailing wind. Backwash carries sediment back down the beach, at right angles to the shoreline.
