6.1/6.2 geological and biological processes of the carbon cycle

Question 1

carbon cycle

Answer 1

The biogeochemical process which cycles/moves carbon from one sphere to another. It is a closed system involving inputs, outputs, throughputs (transfers) and stores (acting as a source and a sink of carbon).

Question 2

carbon store

Answer 2

A stage of the carbon cycle which sees carbon being stored for a given period of time. They can act as sinks and sources of carbon.

Question 3

mechanical weathering

Answer 3

The physical breakdown of rock material by environmental factors (such as changes in temperature).

Question 4

chemical weathering

Answer 4

The change in chemical composition as a result of chemical reactions with elements in rock material (such as oxidation or hydrolysis).

Question 5

biological weathering

Answer 5

The breakdown of rock by plants, animals or bacteria (e.g. tree roots, rabbits burrowing).

Question 6

terrestrial carbon stores

Answer 6

Examples of these stores include sedimentary rocks and soil.

Question 7

ocean carbon stores

Answer 7

Examples of these include CO2 dissolving in to oceans, biological processes (e.g. respiration) of organisms and deeper ocean dissolved inorganic carbon.

Question 8

atmospheric carbon stores

Answer 8

Examples of these include carbon dioxide (CO2) and methane (CH4) (GHG).

Question 9

transportation

Answer 9

Where rivers/oceans transport rock particles (ions) or sediment before they are deposited.

Question 10

sedimentation

Answer 10

The process whereby sediment (dead organisms, river sediment) is buried by subsequent layers of sediment. The accumulation and compaction of these sediments create sedimentary rocks.

Question 11

carbonate rocks

Answer 11

Sedimentary rocks composed primarily of carbonate minerals (CO3). The two major types are limestone, which is composed of calcite (CaCO3) and dolostone, which is composed of the mineral dolomite (CaMg(CO3)2).

Question 12

metamorphosis

Answer 12

The layering/burial of sediments, and associated pressure, leads to sedimentary rocks being transformed in to metamorphic rocks (e.g. shale to slate, and chalk to marble).

Question 13

coal

Answer 13

Formed from the remains of trees, ferns and other plants. Examples of types of coal include anthracite and bituminous coals (highest energy density), lignite and brown coal (lower in carbon, more polluting) and peat.

Question 14

outgassing

Answer 14

Release of pockets of CO2 at active/passive volcanic zones (subduction at convergent margins and divergent margins/mid-ocean ridges, hot springs/geysers and from fractures in the Earth’s crust.

Question 15

permafrost

Answer 15

Soil, rock or sediment that is frozen for more than two consecutive years. In areas not overlain by ice, it exists beneath a layer of soil, rock or sediment, which freezes and thaws annually and is called the “active layer”.

Question 16

marine biota

Answer 16

Organisms, such as plankton, that live in marine ecosystems.

Question 17

lithosphere

Answer 17

The rigid outer part of the earth, consisting of the crust and upper mantle.

Question 18

phytoplankton

Answer 18

Autotrophic (self-feeding) marine algae (microscopic plants).

Question 19

zooplankton

Answer 19

Heterotrophic microscopic animals.

Question 20

sequestering

Answer 20

The natural storage of carbon by physical or biological processes (e.g. photosynthesis).

Question 21

photosynthesis

Answer 21

Process used by plants and some bacteria to convert light energy into chemical energy. This can later be released to fuel the organism.

Question 22

thermohaline circulation

Answer 22

The global system of ocean currents driven by differences in temperature (thermo) and salinity (saline).

Question 23

oceanic carbon pump

Answer 23

Processes to circulate and store carbon in oceans.

Question 24

biological pump

Answer 24

Sequestration of CO2 to oceans by phytoplankton.

Question 25

carbonate pump

Answer 25

Involves inorganic carbon sedimentation. Where shells/skeletons of dead marine organisms, such as lobsters, sink and dissolve and add to the ocean sediments.

Question 26

physical pump

Answer 26

Concerning the (thermohaline) oceanic circulation, upwelling and downwelling of water. The colder the water, the more potential for CO2 to be absorbed. CO2 concentration is 10% higher in deep ocean areas compared to surface waters.

Question 27

primary producers

Answer 27

Autotrophs that generate their own food using light energy from the sun or inorganic compounds. They are the first stage of any food chain/web.

Question 28

respiration

Answer 28

The process whereby living organisms produce energy, typically with the intake of oxygen and the release of carbon dioxide.

Question 29

consumer organisms

Answer 29

Organisms of an ecological food chain that receive energy by consuming other organisms. Primary consumers tend to be herbivores, secondary and tertiary consumers tend to be carnivores or omnivores.

Question 30

dead organic matter

Answer 30

Anything that contains carbon compounds that were formed by living organisms. It covers a wide range of things like leaves, branches, moss, algae, any parts of animals, manure, droppings, sewage, insects and microbes.

Question 31

decomposition

Answer 31

The breakdown of organic matter by bacteria and fungi.

Question 32

system feedback

Answer 32

Occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. Feedback can be positive (results in an increase of the process/event) or negative (results in a reduction of the process/event).

Question 33

carbon balance

Answer 33

The balance of transferred and stored carbon in the atmosphere, ecosystems and soils/rocks.

Question 34

anthropogenic influences

Answer 34

The impacts of human activity on the carbon cycle.

Question 35

fluxes

Answer 35

The flow, or movement of organic compounds (i.e. carbon) through an ecosystem.