1.b. The carbon and water cycles are systems with inputs, outputs and stores.

Question 1

What does the global water cycle consist of?

(The Global Water Cycle)

Answer 1

A number of reservoirs where water is stored for variable lengths of time, and the linkages or pathways between these reservoirs.

Question 2

How much of all global water is contained within the ocean?

(The Global Water Cycle)

Answer 2

The oceans contain 97% of all water on the planet and dominates the global water cycle.

Question 3

Fresh water comprises only a tiny proportion of water in the ocean store.

How much fresh water is frozen in the ice caps of Antarctica and Greenland.

(The Global Water Cycle)

Answer 3

3/4 of fresh water is frozen in the ice caps of Antarctica and Greenland.

Question 4

How much of all fresh water is stored below ground in permeable rocks?

(The Global Water Cycle)

Answer 4

1/5 of all fresh water.

Question 5

Is most of the water in the water cycle contained within the atmosphere?

(The Global Water Cycle)

Answer 5

Given its pivotal role in the water cycle, it may be surprising that only a fraction of the Earth’s water is found in the atmosphere.

Question 6

Why is there so little water in the Earth’s atmosphere?

(The Global Water Cycle)

Answer 6

There are rapid fluxes of water into and out of the atmosphere.

The average residence time of a water molecule in the atmosphere is just 9 days.

Question 7

According to US geological survey estimates, how much water does the global water cycle budget circulate each year as inputs and outputs between the principal water stores?

(Inputs and Outputs of Water)

Answer 7

Around 505,000km3 of water a year.

Question 8

Outline inputs of water to the atmosphere.

Answer 8

Water vapour evaporated from the oceans, soils, lakes, and rivers,

Water vapour transpired through the leaves of plants.

Together these processes are known as evapotranspiration.

Question 9

How does moisture leave the atmosphere?

Answer 9

As precipitation (e.g. rain, snow).

As condensation (e.g. fog).

Question 10

What 3 features release water through ablation?

Answer 10

Ice sheets, glaciers, and snowfields.

Question 11

What is ablation?

Answer 11

The removal of surface snow or ice by sublimation and melting.

Question 12

What is deflation?

Answer 12

The removal of surface snow or ice by aeolian processes.

Question 13

Ablation from ice sheets, glaciers, and snowfields may produce what? Where does this go?

Answer 13

Precipitation and meltwater.

This drains from the land surface as run-off into rivers.

Question 14

Most rivers flow to where? Where do rivers in continental drylands drain to?

Answer 14

Most rivers flow to the oceans.

In continental drylands like southwest USA, drain to inland basins.

Question 15

How does water falling as precipitation on land reach rivers?

Answer 15

Water falling as precipitation on lands reaches rivers only after inflitrating and flowing through soil.

Question 16

After water infiltrates soil, gravity allows it to do what?

Answer 16

Percolate into permeable rocks or aquifers.

Question 17

After water percolates into permeable rock, what may happen to it?

Answer 17

The groundwater may eventually reach the surface as springs or seepages.

Question 18

Outline the global carbon cycle.

(The Global Carbon Cycle)

Answer 18

Consists of a number of stores.

Stores are connected by flows.

The majority of carbon in circulation is within: the atmosphere, soil, and plants.

Question 19

What are ‘stores’ also referred to as?

(The Global Carbon Cycle)

Answer 19

Sinks.

Question 20

What are the key places where carbon can be stored?

(The Global Carbon Cycle)

Answer 20

Carbonate rocks (limestone and chalk). This happens in the slow carbon cycle.

Deep ocean sediments.

Dissolved CO2 in ocean water.

Question 21

What are ‘flows’ also referred to as?

(The Global Carbon Cycle)

Answer 21

Fluxes.

Question 22

How much carbon is stored in the atmosphere?

(The Global Carbon Cycle)

Answer 22

600 billion tonnes.

Question 23

How much carbon is stored in the oceans?

(The Global Carbon Cycle)

Answer 23

38,700 billion tonnes

Question 24

How much carbon is stored in sedimentary rocks?

(The Global Carbon Cycle)

Answer 24

60,000,000 - 100,000,000 billion tonnes.

Question 25

How much carbon is stored in sea floor sediment?

(The Global Carbon Cycle)

Answer 25

6000 billion tonnes.

Question 26

How much carbon is stored in fossil fuels?

(The Global Carbon Cycle)

Answer 26

4130 billion tonnes.

Question 27

How much carbon is stored in land plants?

(The Global Carbon Cycle)

Answer 27

560 billion tonnes.

Question 28

How much carbon is stored in soils and peat?

(The Global Carbon Cycle)

Answer 28

2300 billion tonnes.

Question 29

How long is carbon stored for within the slow carbon cycle?

(The Slow Carbon Cycle)

Answer 29

Millions of years.

Question 30

Flows of carbons within the slow carbon cycle varies between how many times each year?

(The Slow Carbon Cycle)

Answer 30

Between 10-100 million tonnes per year.

Question 31

What happens first in the formation of carbonate rocks?

(The Slow Carbon Cycle)
(Formation of carbonate rocks)

Answer 31

Dissolved CO2 is absorbed by marine organisms.

E.g. coral polyps - these take the dissolved carbon and calcium in ocean water to from calcium carbonate exoskeletons.

Question 32

What happens after marine organisms take dissolved carbon and calcium to form calcium carbonate exoskeletons?

(The Slow Carbon Cycle)
(Formation of carbonate rocks)

Answer 32

Their remains will sink to the ocean floor.

They then accumulate and through heat and pressure, they are converted into carbonate rocks.

This process takes millions of years.

Question 33

What is the final process during the formation of carbonate rocks?

(The Slow Carbon Cycle)
(Formation of carbonate rocks)

Answer 33

Carbonate rocks close to the surface may be influenced by weathering.

This would be chemical weathering, in the form of carbonation.

Question 33

Once exoskeletons are converted into carbonate rocks, what happens to them?

(The Slow Carbon Cycle)
(Formation of carbonate rocks)

Answer 33

Carbonate rocks are subducted at convergent plate boundaries.

So at some point they will be fed into composite volcanoes, which will then erupt - transferring them into the atmosphere.

Question 34

How much faster are flows of carbon in the fast carbon cycle, than compared to the slow carbon cycle?

(The Fast Carbon Cycle)

Answer 34

100 times faster.

Question 35

What are the two key components of the fast carbon cycle?

(The Fast Carbon Cycle)

Answer 35

Land plants and phytoplankton.

The atmosphere.

Question 36

Outline the atmosphere’s role within the fast carbon cycle.

(The Fast Carbon Cycle)

Answer 36

Flows of CO2 dissolve into the ocean.

The ocean ventilates carbon back into the atmosphere.

Average residence time of 350 years.

Question 37

How do land plants and phytoplankton influence the fast carbon cycle?

(The Fast Carbon Cycle)

Answer 37

When land plants and phytoplankton die, decomposition adds much of the carbon to the soil.

Some is released into the atmosphere.