Coasts - Weathering and Mass Movement.

Question 1

Mass movement meaning

Answer 1

-the downhill movement of sediment that moves because of gravity.

Question 2

Rockfall

Answer 2

Bits of rock fall off the cliff face,

-usually due to freeze-thaw weathering.

Question 3

Mudflow

Answer 3

Saturated soil (soil filled with water) flows down a slope.

Question 4

Landslide

Answer 4

Large blocks of rock slide downhill.

Question 5

Rotational slip

Answer 5

Saturated soil slumps down a curved surface.

Question 6

Coastal slumping

Answer 6

• a cliff is made up of porous material
• cracks appear in the cliff if there has been a long period of dry weather
• Rainwater infiltrates the cliff
• turns the cliff into saturated soil - making it heavy
• puts pressure on the rocks beneath
• a curved slip pane develops
• cliff gives way and slumps (slides) along the slip pane

Question 7

slip pane

Answer 7

• Rainwater infiltrates the cliff
• due to the porous material
• This then creates a slip plane

Question 8

Freeze-thaw weathering

Answer 8

• water enters cracks in the rock
• temp decreases = water freezes
• cracks expand
• during the day, temp increases = ice melts
• water seeps deeper into teh cliff
• process repeats itself
• bigger/deeper cracks appear

Question 9

Biological weathering

Answer 9

• plants grow + roots grow in the cracks of the rock
• expanding cracks
• pieces of rock break off

Question 10

Chemical weathering

Answer 10

• rainwater/seawater are weak acids
• overtime, coastline becomes dissolved by the acid
• due to the cliff being made up of chalk/limestone

Question 11

chemical weathering refers to

Answer 11

disintegration of rocks through chemical reactions

Question 12

salt weathering

Answer 12

-weakens rock structure = cracks
- seawater evaporates and remaining salt crystallises
- salt spray from sea enters cracks
-causes a dramatic increase in volume

Question 13

mechanical weathering

Answer 13

rocks disintegrated into smaller and smaller pieces

Question 14

eg of mechanical weathering

Answer 14

freeze thaw weathering
salt weathering

Question 15

eg chemical weathering

Answer 15

carbonation
hydrolisis
oxidation

Question 16

carbonation

Answer 16

carbonic acid in rainwater
-reacts with calcium carbonate (limestone)
- soluble so dissolves and is washed away

Question 17

hydrolisis

Answer 17

acidic rainwater breaks down rock
cuases it to rot

Question 18

oxidation

Answer 18

rocks broken down by o2 and water