Marine Processes

Question 1

Name and give a brief definition of 6 types of erosion

Answer 1

1) corrasion - rock sediment within waves hitting and wearing down rock
2) hydraulic action - cracks with air in are pressured when waves compress the air
3) cavitation - receding waves allowing air to expand
4) wave quarrying - energy of wave breaking the rocks
5) solution - soluable rocks being dissolved
6) attrition- rocks within water break ewch other up

Question 2

Give five factors effecting erosion rate

Answer 2

Waves - destructive or constructive?
Fetch - long or short?
Beach formation - beaches absorb wave energy 
Human activity - management strategies 
Geology - chemical make up of the rock
Lithology - physical structure

Question 3

What are the transport processes in the costal system?

Answer 3

Solution - soluble material carried
Saltation - heavy particles bounce along
Suspension - small particles carried within the water
Traction - large boulders

Question 4

Describe the process of long shore drift

Answer 4

Waves approach a beach at an angle due to the pervailing wind, but backwash occurs perpendicular to the coast. Hence there is a zigzagging pattern

Question 5

What are the two types of deposition?

When will depositional occur?

Answer 5

Marine - by the sea
Aeolian - by wind
Occurs where sediment load exceeds the ability of water to carry it

Question 6

With an example of each give the three types of weathering

Answer 6

Chemical - carbonic acid from CO2 will dissolve limstone (CaCO3)
Biological - nesting birds
Physical - freeze thaw, water expands by 10% when it freezes + wetting and drying ( clay gets cracks when it dries out)

Question 7

Give six types of mass movement

Answer 7

1) rockfall - arches + stacks collapse rapidly
2) landslides - softer material slumps triggered by torrential rain
3) mudflow- movement of fine soils, after heavy rain
4) slumping - large sections of unconsolidated ground situated over resistant rocks
5) soil creep - gradual movement of soil forming terracettes
6) run off, overland flow picking up fine sediment

Question 8

What factors increase the chance of mass movement?

Answer 8

Heavy rain - lubrication
Unconsolidated rock
Saturated ground - heavier
Increased weathering or marine erosion

Question 9

What two types of coastline cause the formation of headlands and bays describe how they are formed at each

Answer 9

Concordant = striations are parallel. Waves exploit a crack in more resistant rock which forms a channel into less resistant rock which is rapidly eroded.
Discordant = striations are perpendicular. Less resistant rock is eroded faster

Question 10

Explain the types of landforms associated with headlands and bays

Answer 10

Wave refraction going into a bay means that wave energy is focused on the headlands, so here more erosional features will form.
In the bay wave energy is much lower and so deposition occurs leading to beaches