Coasts Flashcards
What is a coast?
Definition: A coast is a narrow strip of land where the sea meets the land. Coasts are divided into zones depending on what the conditions are like on different section of a coast.
The size and energy of the wave depends on which factors? (5 factors)
The fetch – the length of water over which a given wind has blown
The strength of the wind
How long the wind has been blowing for
Water depth
Width of the water area
What is prevailing wind? In the UK it is from which direction?
The prevailing wind is the most common wind direction. In the UK it is from the southwest.
What are the two types of waves?
Constructive and destructive.
When a wave reaches the shore, the water that rushes up the beach is known as?
The swash.
The water that flows back towards the sea is known as?
The backwash.
The energy of the swash and backwash determine what?
The type of wave.
What are some facts about a Destructive wave?
Created in storm conditions
Wave energy is high, and waves close together
Wave has travelled over a long fetch
Have a strong backwash which erodes the coast
Frequency 11-15/min
What are some facts about a Constructive wave?
Waves that build up the beach and deposit
They have a large swash meaning they carry material far up the beach
Lower and have a longer wavelength
Frequency of 6-9/min
What are the types of erosion?
Abrasion – sand and pebbles are thrown against the cliff by the sea which wears away the cliff
Attrition – boulders and rocks at the base of the cliff are rolled around by the sea until they wear away and eventually become sand
Solution – salt in the sea water reacts with certain rock types e.g., limestone.
Hydraulic action – as water hits the cliff, air is trapped in any cracks in the cliff. When the wave goes back this air is release with pressure that wears away the cliff.
All these types of erosion happen at the cliff foot – base of the cliff.
What is mass movement? And what are their types?
Mass movement is the large scale, downward movement of material due to gravity. There are 4 types:
Rockfall
Mudflow
Landslide
Rotational slip
