OCR A Level ELSS - 5. OCR A Level ELSS 4.1b Systems and Global Water & Carbon Cycles

Question 1

What is an isolated system?

Answer 1

a system that has no interactions with its surroundings

Question 2

What is a closed system?

Answer 2

Linked processes where there are no inputs or outputs of matter. Energy still moves into and out of the network.

Question 3

What is an input?

Answer 3

the addition of energy or matter into a system

Question 4

What is a store or sink in a system?

Answer 4

The part of a system where water or carbon is retained for a period of time.

Question 5

What is a flow/process/pathway in a system?

Answer 5

The mechanism by which water or carbon moves from one store to another.

Question 6

What is an open system?

Answer 6

A cycle or process where inputs and outputs can add or remove material or energy

Question 7

What is dynamic equilibrium?

Answer 7

a state of balance between continuing processes in a system

Question 8

What is the cryosphere?

Answer 8

All frozen water on earth

Question 9

What is the lithosphere?

Answer 9

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

Question 10

What is the atmosphere?

Answer 10

the layer of gases that surrounds Earth

Question 11

What is the biosphere?

Answer 11

all life on earth

Question 12

What is the hydrosphere?

Answer 12

All the water on earth

Question 13

What is the Natural World?

Answer 13

Biomes and ecosystems, for example, not the human or built environment.

Question 14

What does the term Flora mean?

Answer 14

The plants living in a defined are at a defined time

Question 15

What does the term Fauna mean?

Answer 15

The animals living in a defined area at a defined time.

Question 16

What is Carbon?

Answer 16

A black (when solid), non-metallic element with the atomic number 6, the basis of life on Earth, many rocks and fossil fuels.

Question 17

What is the global carbon cycle?

Answer 17

A representation of the movement of carbon between different stores including: Soil (pedosphere), Terrestrial biomass (biosphere), Atmosphere Oceans Sea floor sediments and Sedimentary rocks (lithosphere). Through a series of flows including: Photosynthesis Respiration Decomposition Combustion Oxidation Weathering and Volcanic Activity

Question 18

What is the global water cycle?

Answer 18

A representation of the global movement of water between: 3 major stores (oceans, land and atmosphere) and Through a series of flows (precipitation, evaporation, evapotranspiration and run-off/groundwater flow)

Question 19

How much water is there on earth?

Answer 19

1.4 billion km3

Question 20

How much water is stored in the oceans?

Answer 20

1.3 billion km3 (~ 97%)

Question 21

How much water is stored in the atmosphere?

Answer 21

13,000 km3 (~ 0.001%)

Question 22

How much water is stored on land?

Answer 22

39 million km3 (~ 2.8%)

Question 23

How much water and carbon and for how long does water and carbon stay in the Ocean?

Answer 23

a very large expanse of sea It stores 1.3 billion km3 of WATER (about 97% of global water) Residence time of ~3600 years It stores 38 billion tonnes of CARBON (around 0.038% or global carbon),

Question 24

How much water and carbon and for how long does water and carbon stay in the Atmosphere?

Answer 24

A thin layer of gases surrounding Earth. It stores 13,000 km3 (about 0.001% of Global Water) Residence time of 10 days for water (FAST) It stores 600 billion tonnes of CARBON FAST Carbon Cycle

Question 25

How much water and carbon and for how long does water and carbon stay in the Pedosphere?

Answer 25

the soil layers of Earth. Stores 65 km3 of WATER (about 0.005% of Global Water) Residence time of 2-50 Weeks (FAST) It stores 2,300 billion tonnes of CARBON. FAST Carbon Cycle

Question 26

How much water and carbon and for how long does water and carbon stay in the Biosphere?

Answer 26

Consists of all life on Earth. Any organic material. Stores 0.6km3 of WATER (around 0.00004% of global water) Residence time of 2-50weeks. It stores 560 billion tonnes of CARBON. FAST Carbon Cycle.

Question 27

How much water and carbon and for how long does water and carbon stay in the Cryosphere?

Answer 27

The component of the hydrological cycle where water is locked up as ice and snow. Stores 29,000km3 of Water (around 2% of global water. Residence time of 15,000years Snow and Glacial Ice store insignificant quantities of CARBON. However the trapped CO2 can be used to help understand past climates.

Question 28

How much water and carbon and for how long does water and carbon stay in the Lithosphere?

Answer 28

The rigid outer part of the earth, consisting of the crust and upper mantle (Rock). Stores 9,500km3 of WATER (around 0.7% of global water) in aquifers. Residence time up to 10,000 years. Stores 60,000 - 100 million billion tonnes of CARBON. SLOW Carbon Cycle (~150 million years)

Question 29

What is the slow carbon cycle?

Answer 29

The parts of the carbon cycle that take between 100-200million years to complete. It starts in the Atmosphere - where CO2 + Water vapour combine to form carbonic acid making rainfall slightly acidic. This means that chemical weathering (carbonation) takes place on carbonate rocks (like limestone and chalk) which releases some CO2 back to the atmosphere, but the rest is dissolved in water and enters the Hydrosphere, flowing from rivers into the oceans. Oceans are also able to absorb CO2 directly from the atmosphere through direct ocean uptake (diffusion). Marine organisms fix this ocean carbon with calcium to form calcium carbonate as part of their shells and skeletons. When these organisms die they sink to the ocean floor (sedimentation). Over millions of years, heat and pressure convert these shells and skeletons back into carbon-rich sedimentary rocks (Lithosphere). Again, over 100s of millions of years, tectonic plate movement takes these ocean sediments to destructive plate boundaries where, through subduction, the carbon is then released back into the atmosphere in volcanic eruptions. The SLOW CARBON CYCLE moves between 10 and 100 million metric tons of carbon each year.

Question 30

What is the fast carbon cycle?

Answer 30

The parts of the carbon cycle that are between 10 and 1,000 times faster than the slow carbon cycle. It is unique to Earth as it moves carbon through the biosphere. Atmosphere to Biosphere - Land plants (primary producer organisms) and phytoplankton in the oceans absorb CO2 from the atmosphere through photosynthesis and combine it with water to form carbohydrates (sugar/glucose). Biosphere to Atmosphere - Respiration converts sugar and glucose back into CO2. Decomposition and waste gases also releases CO2 and CH4 (methane) back into the atmosphere. Combustion (burning) also releases carbon back to the atmosphere. Biosphere to Pedosphere - Decomposition can release organic carbon into the soils in the form of humus Atmosphere to Oceans through the Biological (organic) pump and Oceans to Atmosphere through diffusion. The FAST CARBON CYCLE moves between 1 billion and 100 billion metric tons of carbon each year.

Question 31

What are phytoplankton?

Answer 31

these are similar to terrestrial plants in that they contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean, where sunlight penetrates the water.

Question 32

How much carbon is added to the atmosphere, oceans and biosphere each year through the combustion of fossil fuels?

Answer 32

10 Gigatons per year