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

Question 1

What type of system are the global water and carbon cycles and what are the major stores on a global scale?

Answer 1

At the global scale, water and carbon flow in closed systems between the atmosphere, oceans, land and biosphere.

Question 2

At the macro scale, what are the three main stores of the global water cycle and which is the biggest?

Answer 2

The oceans are by far the biggest (97% of global water) and the atmosphere is the smallest (0.001%)

Question 3

By what processes does water move between stores?

Answer 3

precipitation, evapotranspiration, run off and ground water flow

Question 4

In thousands of cubic kilometres, how much water does each of the 3 main stores contain?

Answer 4

ATMOSPHERE 13
LAND 39,000
OCEANS 1,370,000

Question 5

What are the main pathways taken by carbon between stores? (4/6)

Answer 5

photosynthesis, respiration, oxidation(combustion and decomposition) and weathering

Question 6

How do the carbon and water cycles characteristics change at smaller scales?

Answer 6

The global c/w cycles are closed systems because only energy (the suns energy) cross system boundaries, no matter. whereas on smaller scales, e.g. a drainage basin or a forest ecosystem, both cross system boundaries and these are therefore open systems.

Question 7

By what process does water get from the
a. atmospheric store to the land store
b. land to atmosphere
c. land to oceans
d. oceans to atmosphere

Answer 7

a. Precipitation
b. evapotranspiration
c. Run-off/ground water flow
d. evaporation

Question 8

What are the residence times for carbon in each main store?
1. Atmosphere
2. Oceans
3. sedimentary rocks
4. Terrestrial biomass

Answer 8

1. 6 years
2. (surface) 25 years, (deep) 1250 years
3. 150 million years
4. 18 years

Question 9

Of each global reservoir of water, give the %of global water contained within it.
- oceans,
- polar ice and glaciers,
- groundwater(aquifers),
- lakes,
- soils,
- atmosphere,
- rivers,
-biosphere

Answer 9

oceans 97
ice 2
groundwater 0.7
lakes 0.01
soils 0.005
atmosphere 0.001
rivers 0.0001
biosphere 0.00004

Question 10

considering its pivotal role in the global water cycle, explain briefly why the atmosphere store hold so little water

Answer 10

rapid flux of water between this store and others. Average residence time is just nine days.

Question 11

how much water does the US geographical society estimate is circulated per year?

Answer 11

505,000km3

Question 12

What are inputs into the atmosphere?(water cycle)

Answer 12

water vapour evaporated from oceans, soils, lakes and vapour transpired from leaves. (EVAPOTRANSPIRATION)

Question 13

What are outputs from the atmosphere (water cycle)

Answer 13

moisture leaves the atmosphere by precipitation and condensation. ice sheets, valley glaciers and snowfields release water by ablation (melting and sublimation) goes to land store

Question 14

outputs from land store (water cycle)

Answer 14

precipitation and meltwater drain from the land as run off into rivers most rivers drain into oceans, though some in content drylands like southwest USA, drain to inland basins. A large part of water that falls as precipitation percolates down into the ground and only reaches rivers as groundwater flow after infiltrating into the soil.

Question 15

what may water do after infiltrating into the soil?

Answer 15

percolate into permeable rocks or aquifers, eventually reaching the surface as springs or seepages and contributing to run off.

Question 16

In thousands of tonnes, how much carbon is in each principle carbon store?
Atmosphere
oceans
sedimentary rocks
sea floor sediments
fossil fuels
land plants
soils/peat

Answer 16

Atmosphere 600
oceans 38,700
sedimentary rocks 60,000-100,000,000
sea floor sediments 6,000
fossil fuels 4,130
land plants 560
soils/peat 2,300

Question 17

what is by far the biggest carbon store?

Answer 17

Carbonate(sedimentary) rocks.

Question 18

The slow carbon cycle pt. 1- creation of carbonaceous sea-floor sediments

Answer 18

Carbon stores in rocks, sea floor sediments and fossil fuels is trapped for millions of years. the total amount of carbon circulated by the slow carbon cycle is between 10 and 100,000,000 tonnes per year.
Co2 diffuses from the atmosphere into the oceans. Marine animals use the dissolved carbon to make their shells and skeletons by combining it with calcium to form calcium carbonate. on death, the animals sink to the ocean floor and over millions of years heat and pressure compress them into carbon rich sedimentary rocks.

Question 19

The slow carbon cycle part 2 - how carbon leaves carbonaceous rocks

Answer 19

the typical residence time for carbon In carbonate rocks is 150 million years. Some carbon rich sedimentary rocks are subjected into the upper mantle at plate boundaries and vented into the atmosphere in volcanic eruptions. Other, exposed at earth’s surface by erosion and are attacked by chemical weathering. carbonation causes co2 to be released into the atmosphere and dissolved into streams, rivers and oceans.

Question 20

Slow carbon cycle - fossil fuels (final part)

Answer 20

on land, partly decomposed organic material may be buried beneath younger sediments to form carbonaceous rocks such as coal, lignite, oil and natural gas. like sea floor sediments, fossil fuels act as carbon sink that can endure for millions of years

Question 21

The fast carbon cycle pt .1 - difference between fast and slow cycles

Answer 21

carbon circulates rapidly between the atmosphere, oceans, biosphere and soils. these transfers are between 10 and 1000 times faster than this ein the slow carbon cycle.

Question 22

The fast carbon cycle part 2 - photosynthesis, phytoplankton and land plants

Answer 22

Land plants and microscopic phytoplankton are key components in the fast carbon cycle. As they photosynthesis, they absorb carbon from the atmosphere and combine it with water to make carbohydrates. Photosynthesis is a fundamental process and foundation of the food chain.

Question 23

fast carbon cycle part 3- respiration and decomposition

Answer 23

respiration is the opposite if photosynthesis and returns carbon to the atmosphere. decomposition of dead organic material by microbial activity also returns co2 for the atmosphere.