Erosional Landforms Flashcards
Wave refraction
When waves approach an irregularly shaped coastline, it is slowed by the friction in the shallower water off the headland.
At the same time, the part of the wave approaching the bay is not slowed because the water is deeper.
This makes the wave refract around the headland and ORTHOGONALS converge. Wave energy and erosion is focused on headlands. On the bay, ORTHOGONALS diverge and energy dissapates causing deposition.
LSD movement from eroded material to bays also contributes to build up of beach sediment.
Geos formation
They are narrow steep sided inlets. Even in concordant coastlines there may be joints of faults
They are eroded more quickly by wave action.e.g hydraulic action may be important at forcing air and water into joints weakening the strata.
They initially form as tunnel- like caves at right angles to the cliff line which are enlarged by continued erosion which causes the roof to collapse, creating a geo.
Example: huntsmans leap, pembrokeshire
Blowhole formation
Even in concordant coastlines there may be joints of faults
They are eroded more quickly by wave action.e.g hydraulic action may be important at forcing air and water into joints weakening the strata.
They initially form as tunnel- like caves at right angles to the cliff line which are enlarged by continued erosion which causes part of the roof to collapse along the verticle master joint, creating a blowhole.
Example: trevone, cornwall
What influences shore platforms?
Mainly formed by erosion but weathering processes are also important.
Solution, freeze thaw and salt crystallisation may occur depending on rock type and climate
At night, algae release CO2 which mixes with sea water making it more acidic and resulting in higher rates of chemical weathering
