Weathering processes - Sub-aerial

Question 1

Name the 5 sub-aerial weathering processes.

Answer 1

Frost shattering.
Salt crystallisation.
Wetting and drying.
Solution.
Biological action.

Question 2

What is frost shattering?

Answer 2

Its promoted by the presence of large amounts of water and the tendency for coastal rocks to be severely cracked by the process of erosion.
Coastal locations tend to be warmer than inland localities, reducing likelihood of frosts.

Question 3

What is salt crystallisation?

Answer 3

Its active at the coast due to presence of saltwater.
In the tidal/splash zone, saltwater is readily available and evaporation leads to the formation of salt crystals.
As the grow, they expert pressure or rocks, gradually breaking apart.

Question 4

What is wetting and drying?

Answer 4

Its active in the tidal/splash zone.
Where clays and shales expand and contract associated with wetting and drying.
Cracks from which further weakens the rock and encourages erosion.

Question 5

What is solution?

Answer 5

Involving the dissolving of soluble minerals.
Affects limestone and chalk.
Solution/carbonation is to enlarge joints in the rocks, creating pitted and jagged rock surfaces.

Question 6

What is biological action?

Answer 6

It involves marine organisms.

Piddocks can drill into solid rock

Seaweed

Algae secrete chemicals capable of promoting solution.

Birds nesting.

Question 7

Define sub aerial weathering

Answer 7

Slow breakdown of the coastline, which weakens underlying rocks and allows sudden movement to occur makes erosion and mass movement occur more easily.

Broken down in situ

Question 8

What is sub aerial weathering categorised into ?

Answer 8

Physical

Biological

Chemical

Question 9

What does physical weathering depend on ?

Answer 9

Nature of the climate.

Eg freeze thaw weathering.

Question 10

When does chemical weathering occur ?

Answer 10

Where rocks exposed to air and moisture.

Solution 
Oxidation 
Hydration 
Hydrolysis 
Carbonation