Coastal landscapes Flashcards
what 3 factors is the energy of a wave determined by
- strength of wind
- duration of wind
- distance / fetch
how does wave height increase
the wind pulls waves the surface through friction causing ripples to form
give me 3 features of constructive wave
- depositional
- strong swash weak backwash
- low frequency
- low wave height
- large wavelength
give me 3 features of a destructive wave
- strong backwash weak swash
- short wave length
- high wave height
- erosional
what are the 3 erosional process along a coastline and define them
abrasion - when sediment scrap and bang against coast wearing it away
attrition - rocks and pebbles hit each other wearing each other down and get smaller
hydraulic action - waves cause air to force through cracks the high pressure cause it to crack open and widen and air expands
give me a example of mechanical weathering and define it
freeze thaw - water enters cracks and freezes and expands to up to 10% causing more cracks to grow due to pressure and fragments to break away over a repeated cycle
give me a example of chemical weathering with an example
carbonation - this is when acid rain reacts with calcium carbonate to form soluble which is carried away by water
What are some common forms of mass movement
rockfall
landslides
mudflow
rotational slump
what is a rockfall
fragments and chunks of rock falling off a cliff face resulting in freeze thaw
what is landslide
sliding of chunks of rock due to lack of friction as water lubricates
what is mudflow
when saturated soil flows down hill /slumping causing bulge at bottom
what is rotational slump
when soil and rock fragments become saturated due to water and instead create a head at the bottom of cliff
tell me the 4 method of transportation in rivers
traction
saltation
suspension
solution
what is traction
the rolling of large boulders along seabed
what is saltation
the bouncing of pebbles too heavy