coasts-coastal erosion and weathering

Question	Answer
hydraulic action	Destructive waves compress air into small cracks at the base of the cliff and when the backwash retreats there is a small explosion of released air pressure that weakens the rock.
abrasion	Small pieces of rock are picked up by a wave and hurled against the cliff wearing it away.
attrition	Pieces of rock are bumped together within the water and small chunks break off eventually creating small smooth pebbles.
freeze-thaw	Mechanical weathering- Water seeps into cracks in the rock during the day and at night the water freezes, expands and puts pressure on the crack widening it. Next day more water seeps in and the process repeats until a bit of the cliff breaks off.
salt-weathering	Mechanical weathering- (this can only happen in places where there is salty water). Salty water seeps into a crack in a rock. The water will then evaporate leaving behind the crystallised salt that begins to put pressure on the crack as more and more salt crystallises. Eventually a bit of rock will be detached
weathering	The breaking down of rock without moving it.
carbonation	Carbolic acid in rainwater reacts with limestone and dissolves it over time.
hydrolisis	Acidic rainwater causes the rocks to rot - producing clay and soluble salts.
erosion	The breaking down of rocks and moving them from their starting position.
oxidisation	Water reacts with oxygen to rust rocks rich in iron weakening them and giving them a reddish colour.

Resource summary

	Created by Gabriel Keen over 7 years ago