Geomorphological Processes

Question 1

What are the 4 processes?

Answer 1

Coastal weathering
Mass movement
Transportation
Erosion and deposition

Question 2

Which are the marine processes?

Answer 2

Transportation
Erosion and deposition

Question 3

What are the sub aerial processes (on land)?

Answer 3

Weathering
Mass movement

Question 4

What are the 3 types of coastal weathering?

Answer 4

Biological
Chemical
Mechanical (physical)

Question 5

What is biological weathering?

Answer 5

-the breakdown of rocks by organic activity

Question 6

What are some examples of biological weathering?

Answer 6

• thin plants roots grow into small cracks in a cliff face, these cracks widen as the roots grow, breaks up the rock
• water running through decaying vegetation becomes acidic, which leads to increased chemical weathering
• birds e.g. puffins, and animals e.g. rabbits dig burrows into cliffs

Question 7

What is chemical weathering?

Answer 7

A chemical reaction where salts may be dissolved or clay like deposit may result which is then easily eroded

Question 8

What are some examples of chemical weathering?

Answer 8

Carbonation = rainwater or sorbs c02 from a weak carbonic acid. This reacts with calcium carbonate in rocks e.g. chalk, to form calcium carbonate, which is easily dissolved
Oxidation = the reaction of rock minerals with oxygen e.g. iron, to form a red rusty powder
Solution = the dissolving of rock minerals e.g. halite

Question 9

What is mechanical weathering?

Answer 9

Involves the breakup of rocks without any chemical change taking place

Question 10

What are some examples of mechanical weathering?

Answer 10

Frost shattering (freeze thaw) -occurs when water enters a crack when it rains and then freezes making it expand and crack
Salt crystallisation - when slat water evaporates it leaves salt crystals behind , grows overtime and exerts stresses in the rock causing it to break up
Wetting/drying - rocks rich in clay expand when they get wet and contract when dry, causing them to crack and break up

Question 11

How does geological climate affect rate of biological weathering?

Answer 11

Need plants and animals living there
A climate that is good for plant growth

Question 12

How does geological climate affect rate of chemical weathering?

Answer 12

Dependant on human activity (pollution and factories releasing acid/chemicals)
Rock type is important e.g. ones that go through oxidation

Question 13

How does geological climate affect rate of physical weathering?

Answer 13

Climate/temperature changes - temperature fluctuations e.g. uk, freezing over night then melting during day

Question 14

What is positive feedback?

Answer 14

If the rate of debris removal exceeds the rate of weathering and mass movement then a positive feedback can operate, as the rate of weathering and mass movement could increase

Question 15

What is negative feedback?

Answer 15

If debris removal is slow and ineffective, this will lead to a build up of an apron debris that reduced the exposure of the cliff face. Weathering and mass movement rates will decrease

Question 16

What is mass movement?

Answer 16

The downhill movement of weathering material under the force of gravity

Question 17

What are some types of mass movement?

Answer 17

Soil creep/solifluction
Mudflows
Run off
Landslide/slip
Rock fall

Question 18

What are the 5 processes of erosion?

Answer 18

Hydraulic action
Wave quarrying
Abrasion
Attrition
Solution

Question 19

What are some factors effecting a rate of erosion?

Answer 19

• rock type/structure
• coastal defences
• wave type
• wind speed
• weather conditions
• beach size
• cliff profile
• air pressure
• acidity of water
• fetch lenght

Question 20

What are the 4 processes of transportation?

Answer 20

• traction
• saltation
• solution
• suspension

Question 21

What 2 factors will be key in determining how an individual particle is moved at a coastline?

Answer 21

• size of sediment
• energy of the waves

Question 22

What process moves material along a beach?

Answer 22

Long shore drift

Question 23

How do grones (coastal management) create a positive feedback leading to higher rates of erosion?

Answer 23

As they prevent sediment from moving along, so an area will have little beach to absorb wave energy, therefore its easier to erode as nothing will be in the way

Question 24

How do sea walls affect erosion rates?

Answer 24

Received sea walls will push waves back out to sea, meaning that all the energy will be focused along the front sides of walls

Question 25

How does coastal deposition work at high energy coasts?

Answer 25

Small particles (clay/sand) easily transported whilst larger and heavier material is deposited, forming shingle beaches

Question 26

How does deposition work at low energy coast lines?

Answer 26

Even the smallest material is deposited forming mudflats and salt marches