3.1.3.2 Systems and processes Flashcards
(31 cards)
Outline the sources of sediment
- rivers (90%)
- cliff erosion (5%)
- offshore bars (5%)
Define tides
The periodic rise and fall of the ocean surface
Define currents
Permanent or seasonal movement of surface water
What are the 3 types of currents?
- longshore drift
- rip currents
- upwelling
Define a spring tide
When the earth, sun and moon align and the highest tidal ranges are produced
Define a neap tide
When the earth, sun and moon are at right angles and the lowest tidal ranges are produced
Wave height of a constructive wave
Less than 1m
Wavelength of a constructive wave
Up to 100m
Wave period of a constructive wave
8-10 seconds
Define wave period
Time taken for a wave to travel one wavelength
Wave frequency of a constructive wave
6-9 per minute
Define wave frequency
Amount of waves passing a single point per minute
What is the wave movement of a constructive wave
Elliptical
What is the swash and backwash of a constructive wave
- strong swash
- weak backwash
What is the impact of constructive waves on the beach profile
Gentle slopes
What is the wave frequency of destructive waves
11-15 per minute
What is the wave movement of a destructive wave
Circular
What is the swash and backwash of a destructive wave
- weak swash
- strong backwash
What is the wavelength of a destructive wave
20m
What is the height of a destructive wave
Over 1m
What is the wave period of a destructive wave
5-6 seconds
How many sediment cells are in UK and Wales
11
Define a sediment cell
Closed system, defined stretches of coastline which maintain the majority of sediment, defined by prominent physical features.
What are the 5 main ways to erode a coastline
- abrasion
- hydraulic action
- quarrying
- solution
- attrition
