Carbon Cycle - Booklet 1

Question 1

Name the 4 different carbon stores

Answer 1

• Atmosphere: contains carbon compounds such as methane
• Hydrosphere: holds dissolved Co2
• Lithosphere: carbonate in limestones, fossil fuels and pure carbon in graphite and diamond
• biosphere: as carbon is in the living and dead

Question 2

What is the largest carbon store?

Answer 2

The lithosphere (over 100 million Pg)

Question 3

Describe the properties of lime stone in terms of carbon

Answer 3

• Composed of calcium carbonate, is 40% carbon by weight
• 80% of lithospheric carbon is found in limestone
• Limestone is formed when calcium carbonate is deposited on the ocean floor

Question 4

Explain how the Himalayas has become a major carbon store

Answer 4

The mountain started as ocean sediment that is rich in calcium carbonate that is derived from plankton and corals; since these sediments have been buckled and uplifted the carbon they contain had been weathered, eroded and transported back to the oceans.

Question 5

Explain how chemical weathering causes carbon to released to the atmosphere (geological process of carbon release)

Answer 5

Co2 in the atmosphere reacts with moisture to form weak carbonic acid, thus resulting in the phenomenon aka acid rain; when acid reaches the earth it reacts with some of the surface minerals and slowly dissolves them (chemical weathering)

Question 6

Explain how volcanic outgassing is a source of carbon release (geological process of carbon release)

Answer 6

Pockets of Co2 exist within the earth’s crust, volcanic eruptions and earthquakes can release these gas pockets, this mainly occurs along mid ocean ridges, subduction zones and magma hotspots.

Question 7

What are the 3 forms of carbon

Answer 7

• Inorganic: found in rocks as carbonates
• Organic: found in plant material and living organisms
• Gaseous: found as Co2 and CH4

Question 8

Define what is meant by “carbon sequestration”

Answer 8

Is the transfer of carbon from the atmosphere to other stores, and can be both natural and artificial

Question 9

Explain the formation of fossil fuel deposits

Answer 9

Sedimentation, this process can happen on sea or land. For example when shelled marine organisms die, their shell fragments fall to the ocean floor and become compacted overtime to form limestone.

Question 10

What is the biological water pump

Answer 10

Phytoplankton photosynthesise and produce organic matter with the carbon they absorb, despite accounting for only 1% of the worlds photosynthetic biomass it contributes nearly half of the primary production; as they are the base of the marine food web, carbon is released back into the water due to respiration.

Question 11

What is meant by the physical pump

Answer 11

There would come a point whereby the surface layer of the ocean would become so saturated with carbon such that this process slows down or completely stops; however, oceanic circulation enables the ocean to store even more carbon by providing a constant source of new water (the previously saturated surface watered is transferred into the deep)

Question 12

What is meant by thermohaline circulation

Answer 12

Is an ocean current that produces both vertical and horizontal circulation of cold and warm water around the world’s oceans.