6.1

Question 1

how geological process store carbon for a long time

Answer 1

• Shell building organisms make shells from calcium carbonate, phytoplankton also sequesters carbon
• Remains of these organisms accumulate on sea floor and are layered by sediment which makes them into limestone
• -Fold mountains can carry limestone to the surface where chemical weathering dissolves the rock into calcium carbonate ions which are then carried by rivers back to the ocean
• Over many years the heat and pressure compresses the mud and carbon forming shale
• anaerobic decay takes place , this process takes place over millennia, when organic matter builds up faster than it can decay, layers of organic carbon become fossil fuels instead of shale
• carbon used today was formed up to 300 million years ago

Question 2

Explain how geological processes release carbon into the atmosphere

Answer 2

Chemical weathering:
-Carbon rich rocks are weathered, combination of rainwater and carbon makes carbonic acid
-calcium ions are transported by rivers into oceans, they are then deposited and buried, turning into limestone
-They are then sub ducted by sea floor under plate boundaries where they rise to the surface within magma and is degassed as CO2
Volcanic outgassing:
-Pockets of CO2 in the Earths crust , disturbance of which may allow fluxes to the atmosphere
-outgassing occurs at subduction zones through volcanoes, geysers, hot springs or are emitted directly through fractures in the Earths crust

Question 3

How does outgassing cause a negative feedback loop ?

Answer 3

-Increase in volcanic activity
-Rise in carbon emissions, loss of carbon from rocks
-increase in global temperature
-Increased uplift and mix of CO2 with vapour
-Acid rain dissolves rocks, the calcium ions are transported to the ocean by rivers
-Greater stores of carbon in rocks, e.g. more limestone is formed
Cycle continues

Question 4

Name terrestrial stores of carbon

Answer 4

Sedimentary rock: 8.3x10^7 Pgc
Organic Fossil Fuels: 1,471 PgC
Permafrost: 1,700 PgC
Soil store: 1,950

Question 5

Name Ocean stores of carbon

Answer 5

Intermediate and deep ocean store: 37,100 PgC

Ocean floor calcareous ooze store: 1,750 PgC

Question 6

How much carbon is stored in the atmosphere

Answer 6

589Pgc

Question 7

Name the bio-geo-chemical fluxes

Answer 7

Photosynthesis: 120 PgC/yr
Atmosphere to Ocean: 80 PgC/yr
Respiration and fire: 120 PgC/yr

Question 8

What system is the carbon cycle

Answer 8

Closed system:
-All carbon remains within the system
Made up of:
-Stores, resevoir/pods/stocks where carbon is held
-Fluxes, the physical mechanisms where carbon travels between stores
-Processes: the physical mechanisms which drive fluxes between their stores

Question 9

What are the 4 carbon stores

Answer 9

• Atmosphere
• Hydrosphere
• Lithosphere
• Biosphere

Question 10

despite the fact human emissions are low compared to natural ones, why are they significant

Answer 10

The problem with extra combustion is the balance in the carbon cycle. Before the industrial revolution the cycle was more or less in balance, however since the revolution, the carbon ppm has increase by 100 in 120 years

Question 11

Explain the process of chemical weathering

Answer 11

Chemical weathering of carbon rich rocks:

• acidic rain weathers carbon rich rocks which dissolve into carbonic acid
• its calcium ions are transported into oceans via rivers
• through geological process the ions are turned to limeston
• The limestone is subducted under and finds itself in magma
• it then becomes degassed as CO2

Question 12

What is volcanic out gassing

Answer 12

pockets of CO2 exist within the Earths crust:

• these pockets can be out-gassed at disturbance zones such as subduction zones, hot springs and geysers
• most of these occur at hotsprings