4 - Coastal Change and Conflict Flashcards
What is hydraulic action?
The force of a wave or river against rock, gradually wearing it away.
What is abrasion?
Bits of rock and sand in waves grind down cliffsurfaces.
What is attrition?
Waves smash rocks and pebbles on the shore into each other, and they break and become smoother.
What is solution?
Acids contained in sea water will dissolve some types of rock such as chalk and limestone.
What are the 4 coastal management strategies?
Hold the line, Adavance the line, Retreat and do nothing.
What is a discordanant coastline?
The differing formation of headlands and bays due to erosion.
What is a concordant coastline?
A longtitudunal coastline running parallel to the coast.
What are the first three steps of formations of caves, arches, stacks and stumps?
- A large crack is opened by hydraulic action.
- The crack grows into a cave by HA and abrasion.
- The cave becomes larger.
What are the last three steps of a formation of caves, arches, stacks and stumps?
- The cave breaks through the headland forming an arch.
- The arch is eroded and collapses into a tall rock stack.
- The stack is then eroded forming a stump.
What is mechanical weathering?
The breakdown of rock without changing it’s chemical composition.
What is chemical weathering?
The breakdown of rock by changing it’s chemical composition.
What is biological weathering?
The breakdown of rock by living things, e.g. plant roots.
What are destructive waves?
The waves that carry out erosional processes, they are high, steep and have a high frequency.
Brief the process to form wave cut platforms.
Erosion at the foot of a cliff forms a wave cut notch. Unstable material above the notch becomes unstable and eventually collapses. This material is washed away and a new notch is formed. This repeated erosion and collapsing results in the cliff retreating. The wave cut-platform is the platform thats left behind as the cliff retreats.
Where do spits form and what are they made from?
Spits form at sharp bends of the coastline, LSD transports sand and shingle in the sea on the bend.
What is a bar?
A bar is when a spit joins two headlands together, and a lagoon can form behind the bar.
