Slow Carbon Cycle and The Fast Carbon Cycle

Question 1

How much carbon is circulated by the slow carbon cycle?

Answer 1

10-100 million tonnes per yr

Question 2

Slow carbon cycle: CO2 transfers

Answer 2

Diffuses from atmosphere to oceans where marine organisms like corals make skeletons by fixing dissolves carbon into CaCO3.

After the organisms die, the sink to the ocean floor, accumulate and over millions of years, heat and pressure turns them into sedimentary rocks

Question 3

Slow carbon cycle: residence time and plate boundaries

Answer 3

150 million years

Some sedimentary rock subducted into upper mantle at plate boundaries and vented into atmosphere during eruptions

Question 4

Slow carbon cycle: weathering

Answer 4

If they are near the surface due to erosion or tectonics, they are attacked by chemical weathering like carbonation via acid rain

Question 5

Slow carbon cycle: fossil fuels

Answer 5

On land, partially decomposed organic matter may be buried to form carbonaceous rock like coal or lignite which act as sinks for millions of years

Question 6

Fast carbon cycle: carbon transfers and residence time

Answer 6

Circulates rapidly between atmosphere, ocean, biosphere and soils

Transfers happen 10-1000 times faster than those in the carbon cycle

Question 7

Fast carbon cycle: plants and phytoplankton

Answer 7

Via photosynthesis, they absorb CO2 from the atmosphere and combine it with water to make carbohydrates.

Thier respiration and decomposition releases CO2 back into the atmsophere

Question 8

Fast carbon cycle: oceans and atmosphere

Answer 8

Atmospheric CO2 dissolves in ocean water while ocean water releases CO2 back into the atmosphere.

Through this exchange, carbon atoms are stored through natural sequestration in oceans for 350 years.