coastal management Flashcards
what is erosion
removal of rock and sand particles as a result of wind and wave action
issues in coastal environments
- development
- rivers/lagoons
- erosion
- pollution
- population growth
- introduced plants
- tourism
what are the four types of coastal erosion
hydraulic action
corrosion abrasion
corrosion solution
attrition
what is hydraulic action
when a wave hits a headland, the trapped air is compressed which weaken the cliff
what is corrosion- abrasion
bits if rock and sand in waves grind down cliff surfaces
what is corrosion (solution)
acids contained in sea water dissolve some rock types
what is attrition
waves smash rocks into smaller particles to use in abrasion
how are sea cliffs formed
large waves break and cut the foot of the cliff causing wave cut notches
these notches enlarge until the cliff collapses
how are headlands and bays formed?
the sea erodes a section of the coast
the soft rock erodes quicker causing bays to form and the hard rock is left forming headlands
how do caves, arches, stacks and blowholes form?
caves occur when waves force their way into cracks in a cliff
arches occur when the cave breaks through to the other side
stacks are formed when the arch becomes bigger and breaks at the top leaving a column
blowholes form when cracks in the rock create a gap right through to the top
what is a crest?
peak of the wave
what is a trough?
bottom of the wave
what is the fetch
distance wind travels over the ocean to form waves
what is the size of a wave influenced by:
wind strength
wind duration
wind speed
what is swash
when the water is washed up the beach