EQ1.1

Question 1

Explain how geological processes release carbon into the atmosphere (6/8marks)

Answer 1

-Carbonic acid is produced as CO₂ within the atmosphere combines with rainfall, dissolving carbonate rocks through chemical weathering. Rivers transport carbon and calcium sediment to oceans to be deposited. -Carbon in shells and skeletons from animals, and organic matter from plants sink to seabed when animals and plants die, building up a strata of limestone, chalk and coal. Calcium ions combine within bicarbonate ions to calcium carbonate and precipitate, calcite sediment is converted to limestone through deposition. The presence of intense heating along subduction zones metamorphoses sedimentary rocks, creating metamorphic rocks that releases CO₂. -Terrestrial carbon within the lithosphere is released into the atmosphere through volcanic out-gassing, with carbonate rocks being dragged into the mantle by rising magma at subduction zones. Volcanic out-gassing at constructive plate boundaries and at mid-ocean ridges tend to be less explosive with less carbon emitted.

Question 2

Explain the importance of fluxes in the carbon cycle (6/8marks)

Answer 2

• Terrestrial sequestration involves CO₂ being taken in by plants through photosynthesis is important to maintain terrestrial life as carbon is passed along the food chain for growth in the form of fats and proteins in consumer animals.
  -Oceanic sequestration and terrestrial sequestration involve CO₂ being taken into the oceans or plants respectively through photosynthesis, acting as a ‘carbon sink’ that reduces the greenhouse effect to maintain global temperatures necessary for life, preventing excessive increases that would contribute to climate change - especially as more CO₂ is released into the atmosphere through the burning of fossil fuels.
  -Fluxes, oceanic and terrestrial sequestration, maintain the dynamic equilibrium of gases within the atmosphere.

Question 3

Explain how geological processes store carbon for a long period of time (8 marks)

Answer 3

• Limestone rocks contain a high concentration of calcium carbonate which is formed by shell building organisms that extract the mineral from seawater as well marine phytoplankton that absorb carbon through photosynthesis
  -The remains of these animals go through sedimentation
  -Carbon in mountain ranges is eroded by acid rain, is washed into the sea and cemented and lithified with other carbon matter
  -Carbon in shale is formed by the aerobic compression, with heat and pressure, of mud containing dead organisms
  When dead organisms decay in silt and mud anaerobically over millennia, the become fossil fuels which store masses or carbon