weathering and erosion

Question 1

what is erosion?

Answer 1

wearing away and removal of material by a moving force (e.g. a wave).

Question 2

what are the three main types of erosion?

Answer 2

•hydraulic action
•abrasion
•attrition

Question 3

what is hydraulic action?

Answer 3

breaking waves compress pockets of air in cracks in a cliff. the pressure may eventually cause the crack to widen, breaking off the rock.

Question 4

what is abrasion?

Answer 4

the wearing away of cliffs by sediment flung by breaking waves.

Question 5

what is attrition?

Answer 5

when rocks transported by waves bump into eachother and break up into smaller pieces, attrition is also how pebbles are formed.

Question 6

what is weathering?

Answer 6

wearing away of rocks in situ(where it is).

Question 7

what are the two types of weathering?

Answer 7

•chemical weathering.
•mechanical weathering.
-freeze thaw weathering

Question 8

what is chemical weathering?

Answer 8

the breaking down of rock caused by a chemical change within that rock.
-salt water can weather cliffs through the process of carbonation.
-common on limestone and chalk cliffs.

Question 9

what is mechanical weathering?

Answer 9

the breaking up of rock without changing its chemical composition.

Question 10

an example of mechanical weathering is freeze thaw composition, what is it?

Answer 10

1. when it rains and then water enters a crack in a rock.
2. the water freezes and expands, widening this crack.
3. the ice melts and then the water goes deeper into the crack.
4. process is repeated until the rock splits.