Carbon eq1.1 Flashcards
1
Q
A
2
Q
What is carbon
A
- a common element on earth
- it exists in gas, liquid & solid forms
- in both biotics & abiotic forms
3
Q
In the carbon cycle, the exchange of carbon is between _ main stores
A
4
4
Q
What are the 4 main stores in the carbon cycle
A
- biosphere - plants & animals
- lithosphere - rocks & sediments
- hydrosphere - oceans
- atmosphere - the air
5
Q
Like in the (1), there is (2) amount of carbon on earth
A
- hydrological cycle
- only a certain
6
Q
What are the 3 forms of carbon
A
- inorganic (found in rock)
- organic (found in plant material)
- gaseous (CO2, CH4)
7
Q
Carbon cycle - Fluxes
stores ____ in size
A
vary
8
Q
What is a carbon flux
A
- the process of transferring the carbon between these reservoirs
9
Q
What do fluxes usually involve
A
- a biogeochemical reaction (photosynthesis, respiration, decomposition & combustion)
10
Q
What can fluxes be measured in
A
Pg - Petagrams
GT - Gigatons
(both equal 1 billion tonnes)
11
Q
What are the different timescales of carbon fluxes
A
- seconds to minutes
- annual
- 10-500 years
- millions of years
12
Q
Give an example of a carbon flux on a time scale of seconds to minutes
A
- plants absorb carbon through photosynthesis then transpire this back into the atmosphere
13
Q
Give an example of a carbon flux on a time scale of annual
A
- seasonal variations in the biosphere (e.g autumn leaves)
14
Q
Give an example of a carbon flux on a time scale of 10-500 years
A
- carbon from dead plant material can be incorporated into soils,
- where it may stay for years, decades or centuries,
- before being broken down by soil microbes, & released back into the atmosphere
15
Q
Give an example of a carbon flux on a time scale of millions of years
A
- organic matter that becomes buried in deep sediments & protected from decay
- was slowly transformed into deposits of coal, oil & natural gas, the fossil fuels we use today
- when we burn these substances once again to the atmosphere in the form of CO2
16
Q
What is the scientific view of how old the earth is
A
4.6 billion years old
17
Q
When did dinosaurs exist
A
- The Mesozoic period,
- in the Triassic & Jurassic eras
18
Q
When did humans first evolve
A
- 300,000 to 400,000 years ago
19
Q
What are Cyanobacteria & Stromatolites
A
- Primitive bacteria, which started photosynthesising, adding oxygen to the atmosphere & absorbing CO2
- This happened un the Cambrian era & this evolutionary step enabled life as we know it to evolve
20
Q
Why is the carboniferous period so significant
A
- From 360 mya to about 300 mya, in the middle of this period, the carboniferous rainforest collapsed, resulting in the depostion of many coal beds
21
Q
Where does the word ‘Carboniferous’ come from
A
- The latin word, ‘carbo’, meaning coal
- Carboniferous means coal-bearing
22
Q
The global carbon cycle, one of the major…………. cycles, can be divided into….
A
- biogeochemical
- geological & biological compounds
23
Q
Describe the ‘Geological carbon cycle’
A
- Slowest reservoir turnover rate - at least 100,000 years
- The rate carbon enters & leaves is very slow
- Carbon is stored in rocks/sediment & only leaves through volcanic emissions or through chemical weathering of rocks
24
Q
Describe the ‘Biological carbon cycle’
A
- Faster reservoir turnover rate
- Carbon is not sequestered for long & flows between oceans, atmosphere & vegetation
25
Define sequestering
* the natural storage of carbon by physical or biological processes, such as photosynthesis
26
Explain the 'Geological Carbon Cycle'
1. Volcano
* Terrestrial carbon, held within the mantle, is released into the atmosphere as carbon dioxide when volcanoes erupt
* This is known as 'outgassing'
27
Explain the 'Geological Carbon Cycle'
2. rainfall
* CO2 within the atmosphere combines with rainfall
* to produce a weak acid (carbonic acid aka acid rain)
* that dissolves carbon-rich rocks, releasing bicarbonates
28
Explain the 'Geological Carbon Cycle'
3. Rivers
* Rivers transport weathered carbon & calcium sediments to the ocean, where they are deposited, aswell as subaerial porcesses at the coastline contributing carbonates to the ocean.
29
Explain the 'Geological Carbon Cycle'
4. organisms
* This carbon found in shells & skeletons from animals, and organic matter from plants
* then sinks to the seabed when animals and plants die.
* Calcium ions combine with bicarbonate ions to form calcium carbonate
* which precipiates and forms calcite sediment,
* overtime this lithifies is and converted to limestone through decomposition and cementation.
30
Explain the 'Geological Carbon Cycle'
5. tectonics
* Carbon-rich rocks are subducted along plate boundaries & eventually emerge again when volcanoes erupt
31
Explain the 'Geological Carbon Cycle'
6. metamorphism
* The presence of intense heating along subduction plate boundaries, metamorphose (or alters) sedimentary rocks by baking, creating metamorphic rocks
* CO2 is released by the metamorphism of rocks rich in carbonates during this process
32
In the carbo cycle there is a natural...
balance between carbon production & absorption within the cycle
33
In the carbo cycle there can be occassional ........... e.g...
* disruptions
* major volcanic eruptions emit large quantities of carbon into the atmosphere
34
What is the impact of volacnic eruptions in the atmosphere
* extra CO2 sent into the atmosphere
* which leads to rising temperatures, increased evaporation & higher levels of atmospheric moisture
* this increases aci rain & therefore chemical weathering which slowly rebalances the cycle
35
Most of the earth's carbon is .............
geological
36
Most of the earth's carbon is geological, & results from:
* the formation of sedimentary carbonate rocks in the ocean
* carbon derived from plants & animlas in shale, coal & other rocks
37
In the oceans today, ....% of carbon-containing rock is from....
* 80%
* shell-building (calcifying) organisims e.g corals & plankton
38
How does the fromation of sedimentary rock form th earth's carbon
-limestone
* After organisms die, they sink to the sea floor
* Overtime layers of shells sediment are cemented together & lithified (turned to rock), storing the carbon in stone - limestone & its derivatives
39
Define calcifying
* to make someting hard, especially by the addition of substances containing calcium
40
How is shale a geological store of carbon
* The remaining 20% of rocks contain organic carbon from organisms that have been embedded into layers of mud
* Over millenia, heat & pressure compresses the mud & carbon, forming sedimentary rock like shale
41
How is coal a geological store of carbon
* fossil fuels were made up to 300 million years ago from the remains of organic material
* organisms once dead, sank to the bottom of rivers & seas, & were covered in silt & sand & then started to decay anaerobically
42
How is coal a geological store of carbon
-Anaerobic decay operates over ........
* millenia
43
How is coal a geological store of carbon
-what are the products of anaerobic decay
methane and carbon dioxide
44
How is coal a geological store of carbon
-the deeper the deposit, the more...
heat & pressure is exterted on the deposits
45
Define soil respiration
* a measure of carbon dioxide (CO2) released from the soil from decomposition of soil organic matter (SOM) by soil microbes
46
Define respiration
* a process in living organisms involving the production of energy, typically with the intake of oxygen & release of CO2
47
Define photosynthesis
* the process by which green plants & some other organisms use sunlight to synthesize nutrients from carbon dioxide & water
48
Define diffusion
* the process by which CO2 interacts with the ocean, either being released or absorbed
49
Define sinking
* descend from a higher to a lower position; drop downwards
50
Define decomposition
* process by which dead organic susbtances are broken down into simpler organic or inorganic matter such as carbon dioxide
51
Define rock cycle
* the basic concept in geology that describes transitions through geological time among the three main rock type: sedimentary, igneous & metamorphic
