Weathering

Question 1

Freeze thaw action - process

Answer 1

As water it expands, it puts pressure on the rock. As the ice melts it flows deeper into the widened joints + process repeats to enlarge the cracks + joints unil it breaks + scree falls

Question 2

How much does water expand by at night

Answer 2

9%

Question 3

Force produced per cm² as ice expands

Answer 3

100kg/cm²

Question 4

Freeze thaw action example

Answer 4

Croagh Patrick, Co Mayo

Question 5

Exfoliation - how high can dessert temperatures get

Answer 5

40+°C. This causes uneven heating, hotter on the outside

Question 6

Exfoliation

Answer 6

Dessert temps > 40°C, at night inner rock contracts from cold. This repeats + outside layer loosens, cracks + pulls away.

Question 7

When of exfoliation most effective

Answer 7

When rocks have strata/joints

Question 8

Diurnal range

Answer 8

Daily highest + lowest temp

Question 9

Physical weathering

Answer 9

Doesn’t change appearance or chemical comp

Question 10

Chemical weathering

Answer 10

Breaks down rock through decomposition. Physical appearance + chemical comp altered

Question 11

Carbonation

Answer 11

Rainwater falls though the atmosphere, mixes with CO2 => weak carbonic acid reacts with calcium carbonate by breaking it down into the calcium bicarbonate

Question 12

Which calcium combo is soluble

Answer 12

Calcium bicarbonate

Question 13

Hydration

Answer 13

Soil forming minerals absorb water + expand, trees the rock + cause it to shatter. Followed by mechanical weathering. Some rocks become soft when wet