coastal erosion + waves Flashcards
(18 cards)
What is the difference between the coast and the ocean?
Coast: The land area where the land meets the sea or ocean.
Ocean: The large body of saltwater that covers most of the Earth’s surface.
Why are the coast and ocean important?
Coast: Important for human activities like tourism, fishing, and shipping. It also provides habitats for many species.
Ocean: Regulates climate, provides food, supports biodiversity, and is vital for trade and transportation.
What and where are the 5 main oceans of the world?
Atlantic Ocean.
Pacific Ocean.
Indian Ocean
Arctic Ocean
What human activities take place at the coast?
Human Activities: Fishing, tourism, shipping, coastal settlements (towns/cities), oil drilling, and recreation (beach activities, surfing).
What causes waves?
Waves are caused by the wind blowing across the surface of the water. The strength and direction of the wind affect the size and speed of the waves.
What are destructive and constructive waves and how do they differ?
Destructive Waves: Strong waves that erode the coastline. They have a steep front and are caused by strong winds.
Constructive Waves: Gentle waves that build up the beach by depositing sand. They have a long, low front.
What causes tides?
Tides are caused by the gravitational pull of the moon and the sun on the Earth’s oceans, which causes the water level to rise and fall.
Can you name and describe the 4 types of erosion?
Hydraulic Action: Waves hit the rocks, causing air to be trapped in cracks, which eventually weakens the rock.
Abrasion (Corrasion): The rubbing of rocks and pebbles against the shore, wearing down the
coastline.
Attrition: Rocks and pebbles smashing together, breaking into smaller pieces.
Solution: The dissolving of rocks by sea water, especially limestone or chalk.
How does erosion create an arch, stack, and stump?
Arch: Formed when waves erode a cave in a headland, eventually breaking through to form a tunnel.
Stack: A tall, isolated column of rock left behind when an arch collapses.
Stump: The remnants of a stack after it has been eroded further, leaving a small, flat-topped rock.
How does erosion create an arch, stack, and stump?
Crack Formation – Waves erode a weakness in a headland.
2. Cave Formation – The crack widens into a cave.
3. Arch Formation – The cave erodes through the headland.
4. Stack Formation – The arch collapses, leaving a stack.
5. Stump Formation – The stack erodes and collapses into a stump.
How and why does a cliff retreat? (Wave-cut platform)
- Erosion at the Base – Hydraulic action and abrasion create a wave-cut notch.
- Undercutting – The notch deepens, making the cliff unstable.
- Collapse – The cliff collapses due to gravity.
- Retreat – The process repeats, causing the cliff to move inland.
- Wave-cut Platform – A flat rocky surface is left behind.
What are the 3 types of weathering?
Mechanical (Physical) Weathering – Rocks break down without chemical change (e.g., freeze-thaw).
2. Chemical Weathering – Rocks break down due to chemical reactions (e.g., acid rain dissolving limestone).
3. Biological Weathering – Living things break down rocks (e.g., plant roots growing into cracks).
What is Longshore Drift?
It is the process that moves sediment along the coastline in a zig-zag motion due to the angle of the waves.
How does LSD work?
Waves approach at an angle due to the wind.
Swash carries sediment up the beach at an angle.
Backwash pulls sediment straight back due to gravity.
This zig-zag motion moves sediment along the coast.
How does LSD create beaches and spits?
LSD transports sediment along the coast.
When the coastline changes shape, deposition occurs.
Beaches form when sand is deposited.
Spits form when deposition extends past a headland.
A hooked end forms if the wind direction changes.
What are the causes of rapid coastal erosion on the Holderness Coast?
Soft Boulder Clay – Easily eroded by waves.
2. Powerful Waves – Driven by strong North Sea winds.
3. Narrow Beaches – Less protection from wave energy.
4. LSD Moves Sediment Away – Prevents beaches from building up.
5. Human Interference – Groynes stop sediment movement, increasing erosion in other areas.
What are the impacts of rapid coastal erosion on the Holderness Coast?
- Loss of Homes and Land – Villages like Mappleton are at risk.
- Business and Infrastructure Damage – Roads and farmland lost.
- Ecosystem Disruption – Habitats destroyed.
- Economic Cost – Expensive to manage.
- Tourism Decline – Beaches and attractions eroded.
