Coastal Processes Flashcards
Hydraulic Action
Force of water crashing against coastline causing material to be dislodged and carried away - creates cracks
Air becomes trapped in cracks in rocks and causes them to break apart
Cavitation
Method of Erosion
Air bubbles compress into cracks in river banks, and eventually burst. This causes small shockwaves which weaken the rock
Wave Quarrying
Process of tall waves with intense force hitting cliff face - have power to destroy large chunks of rock
Abrasion
Method of Erosion
Pebbles grind along sea floor rock platform - smoothening its surface
Solution/Corrosion
Method of Erosion
Where sea salt dissolves certain types of rock (eg: limestone or chalk)
Attrition
Method of Erosion
Where rocks the sea is carrying knock against each other and break apart
Longshore Drift
Wave action occurring due to prevailing winds where sediment is carried along the coast
Swash
Layer of water that travels up shore after wave is broken
Backwash
Layer of water that moves back into sea after wave is broken
Offshore Currents
Continuous, predictable, directional movement of seawater driven by gravity, wind and water density
Traction
Large heavy rocks grinding along sea floor
Solution
Dissolving of rocks by acidic water
Saltation
Little pebbles bouncing along sea floor
Suspension
Light sediment floating through water
Mudflow
Occur on very steep slopes at coastline, with very limited vegetation mud can lose its structure and flow down cliffs
Rotational Slumping
Structurally compact material that makes up cliff becomes saturated by heavy precipitation - this causes cliff face to become heavier until it collapses and slips down - seperating from unsaturated material behind
Soil Creep
Slow downward progression of soil/rock along a slope - influenced by saturation of material or mostly gravity
Types of (Sub Aerial) Weathering
Physical, Eg: - Wetting+Drying, Crystallisation, Freeze Thaw
Chemical, Eg: - Oxidation, Hydrolysis, Carbonation
Biological, Eg: - Cliff Vegetation, Seaweed, Nesting Birds etc
Landslides
Masses of rock/debris moving down a slope, with 4 types:
Falling/Toppling - Rockfall
Rotational and Translational
Flows
Creeps (slow)
Sub-Aerial Runoff
Precipitation accumulation on cliffs - can cause erosion
Aeolian Processes
Onshore wind - blows sand landwards
Can create extensive sand dunes
Transport by saltation, suspension and creep (depends on size of material/strength of wind)
Optimum conditions = large beach
