Deck 30- Water- Hydrological cycle Flashcards
What is the hydrological system and what scale does it operate over?
It is a closed system where water is transferred between stores on a global scale.
What is the atmosphere?
The whole mass of air surrounding the Earth
What is the cryosphere?
The cryosphere refers to areas of land where water is stored in a solid state i.e. frozen as ice or snow.
What is the hydropshere?
The hydrosphere refers to all the stores of water where it is stored in a liquid state e.g. lakes and seas.
What percentage of Earth’s water is stored in oceans?
96.9%
What percentage of Earth’s water is easily accessible as it is stored in rivers and lakes?
0.01%
What is residence time of water?
The average amount of time that water spends in a particular store.
What is the residence time for water stored as atmospheric moisture?
10 days
What is the residence time for water stored in groundwater stores? What problems does this cause?
Up to 10,000 years for deep groundwater. 100-200 years for shallow groundwater. Deep groundwater is hard to access as a drinking source. It is also hard to replenish once it has been depleted.
Why does the residence time vary between stores?
Readily accessible stores such as rivers and lakes tend to have a shorter residence time as water is easily lost to other stores through processes such as evaporation, transpiration and groundwater flow. Stores that are harder to access such as deep groundwater stores have less outputs and water tends to flow more slowly in these areas.
How were global stores of water different during the Last Glacial Maximum compared to today?
Lower amount of water stored in the hydrosphere as sea level was ~125 metres lower than today. Larger amount of water stored in the cryosphere as ice caps extended over larger portions of the northern and southern hemispheres e.g. the majority of the UK was under ice.
How does climate change impact on global stores of water and how does this impact on eustatic sea level?
Colder global climate = more water stored as ice in the cryosphere. This leads to a fall in eustatic sea level.
Warmer global climate = more water stores as liquid in the hydrosphere. This leads to a rise in eustatic sea level.
Why does the global hydrological cycle have no inputs or outputs?
It is a closed system as water cannot be added or removed from Earth/Earth’s atmosphere. This means that the total volume of water is constant and finite.
