Coastal Processes Flashcards
(20 cards)
Define abrasion
Rocks thrown up by waves
Hydraulic action
Pressure from air being compressed in rocks
Cavitation
Waves recede causing air to expand in cracks
Wave quarrying
Wave hitting cliff face
Solution
Rocks dissolved by sea water
Attrition
Bits of rock smash together in the water
Solution (transportation)
Dissolved substances carried along in the water
Suspension
Fine material whipped up by turbulence and carried along
Saltation
Force of water causes them to bounce along the sea bed
Traction
Boulders pushed along by water
Longshore drift
Smash carries sediment up the beach, parallel to the prevailing wind. Backwash carries sediment back down the beach at 90 degree angle to the shore
Two ways in which material is deposited
Marine and aeolian
Describe salt weathering
- caused by saline water
- saline water enters pores or cracks in rocks at high tide
- as tide goes out the rocks dry and the water evaporates forming salt crystals
- as salt crystals form they expand, exerting pressure on the rock
What is biological weathering?
Roots grow into the ground forcing them into cracks causing them to break off
What is a slide?
Material shifting in a straight line
What is slumping
Material shifts with a rotation
What is rockfall
Material breaks up and falls
What is mudflow
Material flows down a slope
What is chemical weathering?
Breakdown of rock by changing chemical composition. Eg. CO2 in rainwater creates acid rain which reacts with calcium carbonate to dissolve the rock
What is mechanical weathering?
Freeze thaw weathering. Water enters cracks in rocks and expands when it freezes. It then melts and freezes again causing the crack to expand and the rock to weaken
