Block 1 (The Concepts Of System And Mass Balance)

Question 1

What type of system is the global hydrological cycle? What does this mean?

Answer 1

Closed system

- This means mass cannot be transported into or out of the system

Question 2

Where does mass move between in the water cycle?

Answer 2

Moves between stores (not out of the cycle/system)

Question 3

What are stores in the global hydrological cycle? E.g?

Answer 3

Reservoirs in which water is held (e.g. the oceans)

Question 4

What are flows in the global hydrological cycle? E.g?

Answer 4

Transfers of water between the stores (e.g. precipitation)

Question 5

What does mass balance mean in regards to the global hydrological cycle?

Answer 5

The total amount of water in the cycle/system does NOT CHANGE

Question 6

What is the amount of water in the global hydrological cycle?

Answer 6

1.38 million km3

Question 7

What are the two types of flows between stores?

Answer 7

Inputs (flow into a store)

Outputs (flow out of a store)

Question 8

Water can change state within the global hydrological cycle. What are the three states?

Answer 8

• Water vapour (gas)
• Liquid water
• Ice (solid)

Question 9

What are the Earth’s 4 ‘spheres’? What do they each mean?

Answer 9

• Lithosphere (solid Earth + its interior) (including soil sub-sphere: ‘pedosphere’)
• Hydrosphere (Earth’s water) (including frozen water sub-sphere: ‘cryosphere’)
• Biosphere (living parts of Earth)
• Atmosphere (gas surrounding Earth)

Question 10

Within each of Earth’s spheres are the water stores, which sphere contains the most water stores?

Answer 10

Hydrosphere

Question 11

What are the Earth’s major water stores? What percentage of total water is held in each?

Answer 11

• Oceans (97%)
• Cryosphere (1.9%)
• Groundwater soil + moisture (1.1%)
• Terrestrial surface water (0.01%)
• Atmosphere (<0.01%)
• Biosphere (<0.01%)

Question 12

What percentage of the Earth’s water is saltwater/freshwater?

Answer 12

Saltwater = 97% (ocean store) 
Freshwater = 3% (other stores)

Question 13

What percentage of the Earth is covered by oceans + Seas?

Answer 13

71%

Question 14

Where is the groundwater and soil moisture store located?

Answer 14

Below the surface of the ground

Question 15

What are two main factors that impact the change in the size of stores?

Answer 15

• Sea level rise

- Cryospheric processes (accumulation + ablation)

Question 16

How is sea level rise an example of change in water store size?

Answer 16

• Naturally the cryosphere shifts between glacial + interglacial periods
• Recent anthropogenic climate change is causing prolonged interglacial period of cryospheric shrinking
• Increased ablation causes sea levels to rise
• The cryospheric store therefore shrinks and the ocean store grows

Question 17

What is the current rate of sea level rise?

Answer 17

Approx 3mm per year

Question 18

What is the name of the most recent glacial period? When was it?

Answer 18

Quaternary period

1.5 mill - 15,000 yrs ago

Question 19

Define accumulation?

Answer 19

The build up of snow and ice in the cryosphere

Question 20

Define ablation?

Answer 20

The change from ice in the cryosphere to liquid water or water vapour, by the process of melting or sublimation

Question 21

Is sea level rise an example of a long term or short term change in water store size?

Answer 21

Long term

Question 22

Are cryospheric processes an example of long term or short term changes in water store size?

Answer 22

Short term (seasonal)

Question 23

How are cryospheric processes an example of change in water store size?

Answer 23

• Seasonal changes to temps in polar regions cause variations in levels of ice accumulation + ablation
• In Winter = temps lower + accumulation increases
• In Summer = temps rise + ablation increases

Question 24

Do seasonal changes in accumulation + ablation rates balance each other out?

Answer 24

Yes

- Artic sea pack ice reduces by approx 50% in Summer due to ablation, but reforms in Winter

Question 25

Sketch the hydrological cycle to show the main stores + transfers

Answer 25

SEE CAMERA ROLL FAVOURITES FOR DIAGRAM

Question 26

What is a process that changes transfer rate between stores in the short term? (Give 2)

Answer 26

Random/extreme weather events
- E.g. storm events increase transfers locally (more precipitation)

Seasonal variations in climate
- E.g. monsoons in E.Asia mean transfers are highest in 3 month period (2/3 annual precipitation during period)

Question 27

When is monsoon season in SE Asia?

Answer 27

June-September

Question 28

What is a process that changes transfer rate between stores in the medium term?

Answer 28

Longer lasting climate change events
- E.g. El Niño involves unusual winds causing warm surface water from Equator to move east towards S+C America, making conditions wetter here + drier elsewhere

Question 29

How often does El Niño occur?

Answer 29

Every 3-7yrs

Question 30

How long does El Niño last?

Answer 30

Approx 18 months

Question 31

Simply define El Niño?

Answer 31

A sea surface temperature anomaly

Question 32

What is a process that changes transfer rate between stores in the long term?

Answer 32

Climate change affects precipitation + evaporation transfers in different areas

• E.g. Naturally induced by Milankovitch cycles
• E.g. Anthropogenic by greenhouse gas emissions