1.1.3: coastal processes and landforms Flashcards
High energy coastlines
Those exposed to the most energy from strong winds and short term change can be quite dynamic
Mass movements
Rock falls or landslides are common because of prevailing, steep slopes
Processes involved with coastal energy
3
mass movements
rock breakdown
rock removal
Low energy coasts
Tend to be depositional and sandy environments which have a shallow gradient
Waves in low energy coastlines
constructive waves that push sediment up the beach
Low energy coastlines tides
micro or macro-tidal
affected by storms
Wave type depends on
4
wind velocity
length of time wind has blown across water
fetch
shape and orientation of coastline
Wave refraction
Waves break onto an irregularly shaped coastline which distorts the spread of wave energy.
Wave refraction at headlands and bays
wave energy:
concentrated at headlands
dissipated in bays
Wave reflection
A wave hitting a vertical surface bounces back without breaking or losing its energy which creates standing waves
Standing wave
undergo the clapotis effect, waves which are reflected off the cliff before they break
Clapotis effect
creates standing waves
Lithological factors
3
hardness
composition
structure
Hardness
effect on processes and landforms
- harder more resistant rock erodes slowly and often produces high cliffs
- rock with less structural strength erodes more quickly with slumping often as a dominant feature
Composition
mineral composition affects the rate of weathering
