Coastal Systems and Landscapes Flashcards
How are waves formed?
1) Friction between wind and surface of sea gives water circular motion
2) Wave height affected by wind speed and fetch
3) Waves break at shore, friction with sea bed slows base of wave and makes motion elliptical
What is suspension?
Fine material whipped up by turbulence and carried along in water.
What is saltation?
Larger particles, force of water bounces them along sea bed
What is traction?
Very large particle pushed along sea bed by force of water
What are landslides?
Material shifting in a straight line
What is slumping?
Material shifting with a rotation
What happens to material in rockfalls?
Material breaks up and falls
What happens during mudflows?
Material flows downslope
What are berms?
Ridges of sand and pebbles found at high tide marks
What are runnels?
Grooves in sand running parallel to shore, formed by backwash
What are cusps?
Crescent - shaped indentations that form on beaches of mixed sand and shingle
How do estuarine mudflats and saltmarshes form?
Form in sheltered low - energy environments
Silt and mud deposited, mudflats develop
Mudflats are colonised by vegetation that is salt-tolerant and survives submergence
Plants trap more mud and silt, gradually build upwards to create exposed saltmarsh areas
Erosion by currents forms channels
How does sea level fall result in coastlines of emergence?
Raised beaches, fall in sea level leaves beaches above high tide mark. Beach sediment becomes vegetated and develops into soil. Can also expose wave-cut platforms and cliffs covered in vegetation are known as relict cliffs.
What are rias?
River valleys partially submerged due to rise in sea level. They have a gentle profile, wide and deep at mouth and narrow and shallow inland.
What are fjords?
Drowned glacial valleys due to rise in sea level, that are straight and narrow. Shallow mouth cause by raised ground due to deposition by glacier, very deep inland.
