Coasts Flashcards
Abrasion
Rock and sand in waves grinds down the cliff
Attrition
Waves knock pebbles together and break them up and smoothen them
Solution
Acid in sea water dissolves rock
LSD
The movement of beach material along the coast by waves which approach at an angle but recede in a straight line
Natural features that shape the coast
- destructive waves
- constructive waves
- discordant coastline
- concordat coastline
- wind
- water depth
Destructive waves
Created in storm conditions
High in energy
Strong backwash and weak awash
Erode coast causing steep beach
Constructive waves
Created in calm weather
Low energy
Strong awash and weak backwash
Build up of coast which deposits material and causes wide flat beach
Discordant coastline
Rock type alternates
Forms headlands as hard rock is eroded less
Forms bays and soft rock erodes more
Concordant coastline
Same type of rock along coastline
When waves attack weak points the outer rock is punctured
Beach material
Shingle- steeper
Sand- gentle profile
Wind
Strong wind moves sand inland and creates sand dunes
Weak wind creates gently sloping beaches e.g. In Brighton
Water depth
Affects speed and strength of waves as they approach shore
Contributes to coast natural environment e.g. Coral reefs will not grow at depths over 50-70n because they need sunlight to photosynthesise
Physical factors affecting coastlines
1) land and location - shape of coastline, relief, rock resistance, beach or no beach
2) weather and climate - rainfall, temp, wind strength, storms
3) sea - wave depth, water level, wave energy, LSD
4) human activity - intervention on natural ecosystems, use of land for development, resource exploitation
Retirement coast
Eastbourne
Resource rich coast
South East Asia