Coasts Flashcards
What are the two types of waves?
Constructive and destructive.
What are three features of a constructive wave?
- strong swash and weak backwash
- transports and deposits material
- does not take material away
What are three features of a destructive wave?
- weak swash
- strong backwash
- erodes and destroys coast by taking material away
What is hydraulic action?
It is a type of coastal erosion characterised by the force of waves hitting against rock, trapping air inside faults and cracks of the rock and eroding the rock
What is abrasion?
Abrasion is the sand-paper-like grinding of rocks together, making them become smooth
What is attrition?
Attrition is the process of rocks clashing into one another, and breaking apart, becoming smaller and more rounded each time
What is solution?
Solution is a process in which sea water dissolves rocks.
What is longshore drift?
How does it work?
How do people try to avoid its effects?
Longshore drift is a process in which material is transported on coasts.
It works in a zig zag pattern, moving material along beach, as waves hit on the coast at an angle and then move material along beach.
Its effects can be somewhat avoided through the use of groynes.
How are spits formed?
Material is carried along a shore via longshore drift, until eventually the mainland ends, but the longshore drift continues. This constant deposition of materials creates a spit. A change in wind direction means a hooked end of the spit.
How are bars formed?
Bars are formed when spits go across a bay, forming a lagoon.
What is hard engineering?
Hard engineering is a traditional method of attempting to decrease effects of coastal erosion, usually ugly, expensive and not eco-friendly.
What is soft engineering?
Soft engineering is a non-traditional method of attempting to decrease effects of coastal erosion, usually prettier, cheaper and eco-friendly.
What are four examples of hard engineering?
Sea wall, rip rap, gabion, groynes…
What are two examples of soft engineering?
Beach replenishment, replanting vegetation, fencing…
What are the cons of a sea wall?
Cons: it removes material from beach, it must be placed correctly, it is very local and it is very expensive.
