Global Carbon Cycle

Question 0

Short time scale - The terrestrial cycle:

Plant biomass carbon amount:

Answer 0

560 x 10^12 kg C

Question 1

Short time scale - The terrestrial cycle:

Atmosphere carbon amount:

Answer 1

760 x 10^12 kg C

Question 2

Short time scale - The terrestrial cycle:

Dead organic matter carbon amount:

Answer 2

1500 x 10^12 kg C

Question 3

Short time scale - The terrestrial cycle:

Answer 3

Atmosphere ➡️ Plant biomass ➡️ Dead organic matter ➡️ Atmosphere.

Question 4

Short time scale - The terrestrial cycle:

Can be broken: DOM may not be fully decomposed into CO2.

Answer 4

May be highly resistant to decay and become preserved as fossil matter.

Preservation may be prompted by anoxic conditions, fossilised to form coal.

Question 5

Short time scale - The terrestrial cycle:

Can be broken: Carbon released from soil may be transported away by runoff:

Answer 5

High during rainfall and floods, otherwise low.

May be influenced by human activity, such as farming.

Question 6

Intermediate time scale - Marine carbon cycle:

Amount of carbon as seabed sediments:

Answer 6

3000 x 10^12 kg C

Question 7

Intermediate time scale - Marine carbon cycle:

Ocean circulation

Answer 7

Brings CO2 rich waters back from depth to the surface.

Question 8

Intermediate time scale - Marine carbon cycle:

Deep ocean: largest reservoir of carbon -

Answer 8

38’000 x 10^12 kg C

Question 9

Intermediate time scale - Marine carbon cycle:

Deep ocean: 1% of organic matter reaches seabed,

Answer 9

The majority decomposes whilst sinking.
Organisms reduce the 1% to 0.1%.

The 0.1% leaks into the long term geological cycle.

Question 10

Intermediate time scale - Marine carbon cycle:

Upper ocean: carbon reservoir -

Answer 10

1000 x 10^12 kg C

Question 11

Intermediate time scale - Marine carbon cycle:

Upper ocean: the top 100m is the

Answer 11

Photic zone.

Question 12

Intermediate time scale - Marine carbon cycle:

Upper ocean: phytoplankton -

Answer 12

Use CO2 to produce O2 through photosynthesis.

Question 13

Intermediate time scale - Marine carbon cycle:

Upper ocean: Zooplankton -

Answer 13

Organic matter produced is use in respiration.

Poop can sink to great depths, decomposing on the way and releasing CO2 into the water column.

Question 14

Long term time scale: Geological carbon cycle:

Calcareous sediment: Made by

Answer 14

Organisms using inorganic carbon.

Question 15

Long term time scale: Geological carbon cycle:

Calcareous sediment: Forms from

Answer 15

Marine deposits of CaCO3 shells and skeletons.

Question 16

Long term time scale: Geological carbon cycle:

Calcareous sediment: Chemical and

Answer 16

Structural changes lead to the formation of chalk and limestone.

Question 17

Long term time scale: Geological carbon cycle:

Calcareous sediment: reservoir -

Answer 17

40’000’000 x 10^12 kg C

Question 18

Long term time scale: Geological carbon cycle:

Calcareous sediment: accumulates at a rate of

Answer 18

0.2 x 10^12 kg C yr-1

Question 19

Long term time scale: Geological carbon cycle:

Carbonaceous sediment: accumulates at rate

Answer 19

0.05 x 10^12 kg C yr-1

Question 20

Long term time scale: Geological carbon cycle:

Carbonaceous sediment: Reservoir -

Answer 20

10’000’000 x 10^12 kg C

Question 21

Long term time scale: Geological carbon cycle:

Carbonaceous sediment: Carbon-rich, containing

Answer 21

Organic material.

Question 22

Long term time scale: Geological carbon cycle:

Carbonaceous sediment: Organic-rich material is continually covered with more

Answer 22

OM and sediments. The overlying weight leads to compaction, squeezing out water and air.

The sediments can be buried to depths of several km and become lithified under high pressures and temperatures.