The Coastal Zone Flashcards
What is the main cause of erosion in a coastal zone?
Destructive waves
Describe a destructive wave?
In a destructive wave the swash is weak and the backwash is strong which means material from the Beach is taken away into the sea
Describe a constructive wave?
A wave with a weak backwash but a strong swash meaning it takes material from the sea and helps build up the beach
Name the four processes of coastal erosion and what they do?
Hydraulic power the sheer weight of the water against the coastline erodes away
The coast. Also waves compress air in the cracks of rocks forcing the apart weakening the rock
Abrasion- the throwing of sand pebbles against the coast
Attrition the rocks and pebbles carried by the waves rub up against the coast (sandpaper effect)
Solution the chemical action on rocks by seawater dissolve some rocks such as limestone and chalk
Name the 3 types of weathering?
Chemical
Mechanical
Biological
What is mass movement?
The downhill movement of material under the influence of gravity
Give me an example of mechanical weathering and how it works?
Freeze thaw
Waiter within the cracks of rock are frozen by the harsh climate and therefore expand over time it expands to the point we’re the rock starts to fall of.
When does chemical weathering occur and give me an example?
When the rocks mineral composition is changed
Limestone is dissolved by carbonation co2 in the atmosphere combines with rainwater to form carbonic acid which changes calcium carbonate to calcium bicarbonate this is carried away by water in solution!
What is causes biological weathering?
Caused by plants and animals and its action speeds up the other forms of weathering for example tree roots widen gaps in rocks
Different types of mass movement depend on what?
The material involved
The amount of water in the material
The nature of the falls
