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Flashcards in Water and Carbon Cycles Deck (83)
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compare and contrast open, closed and isolated systems. use examples for each

open systems allow both matter and energy to pass through the system boundaries, such as the atmospheric cycle. Closed systems only allow energy to pass the system boundaries, such as the energy balance of the earth in the atmosphere, which interacts with radiation from the sun but no matter. Isolated systems do not allow either matter or energy to pass through the system boundaries, and are much rarer to find. On a local scale, an isolated system could warm soup in a flask, as the vacuum flask means there is no interaction with energy or matter.


define closed systems

a system in which only energy, not matter, can pass through the system boundaries


define an open system

a system where both energy and matter can interact past the system boundaries


define isolated systems

a system where neither matter nor energy can pass through the system boundaries


what is positive feedback

where an event's consequences are amplified by subsequent events triggered by the initial event


give an example of positive feedback on a local, regional and global scale

local: soil degradation as a result of overgrazing will lead to further degradation as rainfall will sweep away nutrients, meaning less vegetation will grow there, so more soil will be washed away by heavy rainfall
regional: evapotranspiration reduced by reduced rainfall will mean less rainfall, so less evapotranspiration
global: climate change resulting in ice sheets containing trapped GHG means climate change will be further enhanced, melting more ice sheets


what is negative feedback?

when an event's consequences are reduced by subsequent events triggered by the initial event


give examples of negative feedback locally, regionally and globally

local: volcanic eruption releases carbon into surroundings, however this fertilises soils and leads to more plant growth, so less CO2 is present.
regional: increase in CO2 levels means more vegetation in an area, so less CO2 as it becomes locked in the biosphere
global: increase in temperatures world wide increase transpiration, so more sunlight is reflected, meaning a decrease in global temperatures


give the definition of an output

things which are removed from the system


give examples of outputs for the water and carbon cycles

evaporation removes water from the cycle back to the atmosphere while in the carbon cycle combustion releases carbon to the atmosphere


give the definition of an input

things which are added to a system


give examples of inputs in the water and carbon cycles

water: precipitation
carbon: photosynthesis


define flux

measurement of the rate of flow of material between the stores over time


define store/component

stationary things within the system


define dynamic equilibrium

when inputs and outputs are balanced


define flow/transfer/throughput

the movement of something within a system, often between stores


give the throughputs of the water cycle (7 items)

throughflow, stemflow, infiltration, percolation, groundwater flow, overland flow, channel flow,


define heterotroph

absorbs food, animals


define anthropogenic

humn activity and pollution causes


define anthropogenic

human activity and pollution causes


give the major stores of the water cycle (water basin not global)

atmosphere, water table, aquifers, lakes, oceans


give the major stores of water on earth

hydrosphere, cryosphere, biosphere, lithosphere, atmosphere


give the major flows in the carbon cycle (9 items)

photosynthesis, respiration, consumption, excretion and death, sequestration, formation of sedimentary rocks, combustion, weathering, volcanic eruption


give the major stores of the carbon cycle in order of size

marine and sedimentary rocks ( 100,000 billion metric tonnes), oceans ( 38 000 bmt), fossil fuels (4000 bmt), soil (1 500 bmt), atmosphere (750 bmt), plants (560 bmt)


what is evaporation?

the process in which water in a liquid form becomes a gas by gaining energy. this energy often comes from the sun in the form of radiation, and the water vapour rises into the atmosphere. it then cools and condenses to form clouds.


define precipitation

when water vapour which has condensed to form clouds form droplets around duct particles, or simply become too heavy to remain in the atmosphere, so fall as rain, snow or hail.


what is evapotranspiration?

when water absorbed by plants evaporates in the exposed leaves and stems, when the plant respires (exchange of gases). water is lost more easily, in high temperatures or fast winds.


what is the role of interception in the water cycle?

interception is the process in which precipitation is delayed in reaching the surface due to vegetation blocking its path. interception affects hydrographs, reducing the peak flow as the rainfall takes longer to reach the river channel, so the lag time is greater and so the river has more time to discharge the excess rainwater, meaning the river level rises less.


what is sublimation?

this is when solid water (ice) becomes water vapour without going through the liquid state


what is infiltration?

when precipitation which reaches the surface enters the soil, draining downwards.


what is percolation?

when water moves vertically downwards from above to below the water table


what is groundwater flow?

the movement of water 4 km below the surface to another store


what is overland flow, or surface runoff?

when saturated soil cannot absorb any more water, so additional precipitation or meltwater flows on the surface towards a store


what percentage of the earth's water is saline?



what percentage of the planet's water is freshwater?



what percentage of the earth's freshwater is in the cryosphere and groundwater

68.7% cryosphere, 30.1 groundwater


what percentage of the earth's freshwater is stored on the surface?



what is the dew point?

the temperature at which water condenses


what are the two ways in which clouds can form?

condense on a condensation nuclei (dust)
cools down to sublimate into hoar frost


what is the evaporation rule regarding how much radiation is needed to evaporate water?

the more water is available, the harder it is to evaporate


how much of the world's land was covered in ice 18000 years ago?



when were sea levels 50m higher than today?

3 million years ago


what is ablation?

when glacial ice or snow melts or evaporates


what is calving?

the breaking off of chunks of glacial ice


what is fog?

fog is a cloud which touches the ground


ho do we define ice caps?

masses of ice on land which are smaller than 50,000 km sq.


how do alpine glaciers form?

snow or ice flows from ice caps become compact


why does permafrost, as well as glaciers, play such an important role in climate regulation?

permafrost contains bubbles of trapped GHG, such as methane (CH4) and carbon dioxide (CO2)


what is cryoconite and how does it pose a problem regarding the cryosphere?

cryoconite is a mixture of soot and algae, filling up small holes in the ice, and as it is black in colour, the ice absorbs more light, so heats up and melts, releasing trapped bubbles of GHG. this reduces the albedo potential of the ice, as less light is reflected, so the surface temperature increases.


who is James Balog?

a photographer, who's work in recording ice sheet retreat in Greenland, Alaska and the Arctic, shows that human activity has led to the huge melting of ice there.


how many people would be affected by a sea level rise of 3 feet?

150 million


what are moulins?

steep- sided canyons where meltwater has eroded the ice.


by how much did the Columbia Glacier in Alaska retreat by in 3 years?

2.5 miles


how many out of the 1400 glaciers in the Yukong Territory have disappeared?

300 in 60 years


by what height are some glaciers shrinking by?

Empire State Building


define aquifer.

water stored below the water table in saturated soil rock


define water table

the level below which the ground is saturated with water


what is soil moisture?

water stored in the oil above the water table


how does soil type affect how much water is stored there?

different soils have different pores which hold different amounts of water, such as clay which holds 40-60% of the soil volume as water, while sand only holds 20-45%


what percentage of the soil volume in clay can hold water?



what percentage of the soil volume in sand can hold water?



what percentage of water is stored by interception in needle-leaf forests



define soil moisture budget

the soil moisture budget shows the level of water in the soil, which is affected by precipitation and evapotranspiration.


what is soil moisture recharge?

when precipitation exceeds evapotranspiration, adding to soil moisture


define soil moisture utlisation

when evapotranspiration exceeds precipitation


what is soil moisture deficit?

when evapotranspiration is greater than precipitation


what is soil moisture surplus?

when precipitation exceeds evapotranspiration


what is the equation to calculating soil moisture budget?

P= SF + E +/- change in S
Precipitation = streamflow + evapotranspiration +/- change in storage


rearrange the equation for soil budget for change in storage

P - SF - E = change in S


what are tributaries

rivers or streams which join the main channel


define confluence

the point at which two rivers join to become one channel


what are physical reasons for a flashy hydrograph? 6 items

drainage basins round in shape will cause flashy hydrographs as each point on the basin is equidistant to the river.
steep-sided drainage basin edges will funnel water quickly to the channel
saturated land will increase surface runoff
high precipitation intensity
low vegetation density
impermeable rock type


what are physical reasons for subdued hydrographs?
6 items

long and thin river basins will mean the water will take more time to reach on point on the river
a low relief drainage basin will mean the water is not funnelled to the channel
unsaturated land
low precipitation intensity
high vegetation density
permeable rock


what are human reasons for flashy hydrographs?

deforestation reduces interception and decreases bankfull capacity
furrows in fields drain water to the channel
ploughing wet soil damages subsoil, creating an impermeable layer so increasing overland flow
overgrazing can damage the soil
urban surfaces are largely impermeable


what are human factors for subdued hydrographs?

afforestation increases interception so increase lag time
terracing on hills stops water flows
ploughing loosens the soil so increases infiltration
lakes and reservoirs capture water and stop it from entering the channel directly


why is deforestation a cause of flashy hydrographs?
2 reasons

deforestation not only reduces interception in an area, but soil becomes exposed, so is easily drained to the river channel by heavy precipitation, and the sediment is deposited on the river bed, reducing the bankfull capacity as the channel becomes shallower


define base flow

normal day-to-day discharge of the river ans is the consequence of slow moving soil throughflow and groundwater seeping into the channel


what is lag time?

the time between peak rainfall and peak discharge


define a river's discharge

the amount of water in a river flowing past a certain, measured in cubic metres per second, cumecs


what is bankfull?

bankfull is the maximum discharge that a river channel is capable of carrying out


what is peak discharge?

the point on a flood hydrograph when river discharge is at its greatest


define storm hydrograph

a graph of discharge of a river over the time period when the normal flow of the river is affected by a storm event


what is storm flow?

the discharge resulting from storm precipitation involving both overland flow, throughflow and groundwater flow