Coastal Processes Flashcards
What is “Slumps” ?
Material rotates along a curved slip plane
What is “Slides” ?
Material slides in a straight line along the slip plane
What is “Rockfall”?
Material breaks up and falls down a slope
What is deposition?
When the wave looses energy and slows down, then dropping the heaviest material
What is a fetch ?
The distance of the wind blows over the sea
What’s a constructive wave, and its features?
Builds the beach by depositing material
•swash is stronger
•low frequency
•low & long
Whats a destructive wave, and its features?
Erode the beach
•high frequency
•stronger backwash
•high & steep
Long shore drift…
- Waves follow the direction of prevailing wind
- Waves hit the coast at an oblique angle
- Swash carries material up the beach
- Backwash brings it back at right angle
- Sediment moves in a zig-zag movement along the coast
What is traction?
Large material is dragged along the sea bed
What is slatation?
Smaller material is bounced along the sea bed
What is suspension?
Small particles are carried by the water
What is hydraulic action?
Water compresses air in the cracks causing them to expand and break off
Whats is abrasion?
Sediment in the water is rubbed and scraped against the rock
Whats is Attrition?
Rock collide with each other, becoming smaller and rounder, as bits of rock a broken off
Mechanical weathering: definition…
The breaking down of rock without changing its chemical composition
Process of Freeze-thaw?
1) Water gets into cracks in the rock
2) The temperature decreased below 0°, it freezes and expands the crack
3) Then it thaws and contracts
4) Then the process is repeated, causing rock to break off
Chemical weathering definition…
The breaking down of rock by changing its chemical composition
Process of chemical weathering?
1) Rain is a weak carbonic acid
2) When rain reacts with a rock that has carbonate in it
3) It causes the rock to be dissolved by the rain
