Coasts Flashcards
What causes waves?
The wind dragging over the surface of the water.
Define fetch.
The distance the wind travels over the water.
Define swash.
The water breaking on the sand.
Define uprush.
The water rushing up the sand.
Define backwash.
When the wave retreats back into the ocean
If the backwash has more energy than the uprush, ____
The waves eat at the land.
If the uprush has more energy than the backwash, ____
The material builds up to make a beach.
Define tides.
The rise and fall in sea level, due mainly to the moon.
Define tidal range.
The fall in sea level from high to low tide.
What do waves do?
They wear away or erode the coast, then carry away the eroded material. And finally deposit it in sheltered areas where the waves lose energy.
Define erosion.
The wearing away of rock, stones, and soil by rivers, waves, wind, or glaciers.
What processes happen during erosion?
Hydraulic action - Forcing water into cracks.
Solution - Dissolving soluble material.
Abrasion - The flinging of rocks and sand against the rock, wearing it out.
Attrition - Rocks that knock against each other.
Define longshore drift.
How sand and other material is carried parallel to the shore, by the waves.
Diagram:
↓→↓→↓
lol thats the best i can do :P.
Define headland.
Land that juts out into the sea.
Define wave-cut platform.
The flat rocky area left behind when waves erode a cliff away.
Define bay.
A smooth curve of coast between two headlands.
How does a wave-cut platform form?
1) The waves carve wave-cut notches into cliffs at a headland.
2) They get deeper until the rock above them collapses. The sea carries the debris away.
3) The process continues non stop, leaving a wave-cut platform behind.
Define stack.
A pillar of rock left standing in the sea when the top of an arch collapses.
How do caves, arches, and stacks form?
(simplified)
cliff /~~~| → cave /o\ → arch /~\→ stack []
→ stump <>.
Define stump.
The remains of an eroded stack.
Define spit.
A strip of sand or shingle in the sea.
Define salt marsh.
A low-lying marshy area by the sea, with salty water from the tides.
What do we use the coast for?
- To have fun
- Fishing
- Shipping and ports
- Views
- Transport
What do coastal defences do?
Protect the coast from erosion.
Define sea walls.
Curved defences that reflect the waves.
Define rock armour.
Big rocks that soak up the wave’s energy.
Define revetments.
Fence-like structures that make waves batter against them instead of the cliffs.
Define groynes.
Barriers of wood or stone down a beach, to stop sand being washed away.
Define beach nourishment.
Adding sand to a beach to replace the sand the waves carried away.
