Coasts Flashcards
What are the causes of the Cliff Collapse in Holderness(Yorkshire)?
- Powerful destructive waves cause by long winds and long fetch
- Cliffs made of soft bolder clay
- Eroded material is transported out to sea meaning the beaches are small
- Sea defences along the coast have made the problem worse in some areas
What are the effects of the Cliff Collapse in Holderness(Yorkshire)?
- Loss of diversity in wildlife due to the lack of sediment
- Businesses at risk would lose money
- Buildings close to the cliff edge are at risk of falling into the sea and will not be compensated for this
- The value of people’s homes decreases as nobody wants to live there
How and why do Caves, Arches, Stacks and Stumps happen?
- A large crack opened up by hydraulic action
- The crack grows into a cave by hydraulic action and abrasion
- The cave becomes larger
- The caves breaks through the headland, forming a natural arch
- The arch is eroded and collapses
- This leaves a tall rock stack
- The stack is eroded, forming a stump
What is Longshore drift?
Longshore drift transports sediments along the beach in a zig-zag route
How does Longshore drift happen?
- The wind blows towards the land at an angle(this is called the prevailing wind direction)
- It cause the waves to approach the beach at a slight angle. As they break, the awash carries material up the beach at an angle. Gravity causes the material to be carried straight back down the beach
What are the characteristics of Destructive Waves?
- Weak smash and strong backwash - pulls sand and pebbles of the beach (erosion)
- Steep, high waves that are close together
- Come into the coast quickly
- Creates a steep beach
- Created in storm conditions
- Have a short wave length and are high and steep
What are the characteristics of Constructive Waves?
- Strong slash and weak backwash - build up he beach (deposition)
- Low waves, more gently sloping with a longer gap between them
- Creates a gentle beach
- Created in calm weather and are less powerful
What is Hydraulic Action(erosion)?
Water is forced into cracks in the rock, is compressed(squashed) and forces the rock apart
What is Suspension(transportation)?
Fine sediment is carried along in suspension in the water
What is Abrasion(erosion)?
Loose rocks are thrown against the cliff wearing away at the rock like sandpaper
What is Solution(transportation)?
Dissolved materials are carried along in Solution - you can’t see it
What is Attrition(erosion)?
Loose rocks are swirled around and are worn into smaller, rounder pieces
What is Traction(transportation)?
Large pebbles and cobbles are rolled along the seabed
What is Solution(erosion)?
Seawater dissolves material from the rock
What is Saltation(transportation)?
Small pebbles are moved when a pebble hits another, causing it to bounce
