OCR A Level ELSS - Entire Course 4 Flashcards
biological weathering
the breakdown of rocks through the chemical and physical action of living organisms, e.g. burrowing, tree roots
chelation
a type of chemical weathering by acids derived from rainwater and dead organic matter
canopy
the uppermost layer of treetops and branches in a forest or woodland ecosystem
biodiversity
the number of different plant, animal, fungi etc species in a given area
downwelling
the sinking of dense, salty (or cold) water in the oceans
upwelling
The movement of deep, cold, and nutrient-rich water to the surface
food chain
a series of organism through which food energy moves before it is completely expended
lithification
the transformation of sediments into rock (usually by compression and/or heating)
orographic effect
changes to air flow due to the topography of the land e.g. mountains forcing air to rise
absolute humidity
the mass of water vapour in a given volume of air
relative humidity
the mass of water vapour in a given volume of air as a ratio of the mass needed to saturate it
biomass
A measure of the total dry mass of organisms in a given area
porous rock
rocks which contain pores or air spaces between mineral particles, where water can be stored
nutrient cycle
the continuous movement of nutrients between stores (soil, biomass and litter)
shifting cultivation
A form of subsistence agriculture in which people shift activity from one field to another
commercial farming
agriculture on an industrial scale operated by large companies using heavy machinery
commercial logging
forestry on an industrial scale operated by large companies using heavy machinery
commercial mining
Mining on an industrial scale operated by large companies using heavy machinery
monoculture
the cultivation of a single crop in a given area.
small scale agroforestry
use of small areas of forest to grow crops, raise animals and harvest raw materials, considered to be sustainable
tree line
the latitudinal and altitudinal limit of tree growth.
heat balance
the difference between solar inputs of energy to the Earth-atmosphere system and energy outputs from terrestrial radiation and gases in the atmosphere. Currently inputs exceed outputs and the global climate responds by warming
active layer
the upper layer of permanently frozen soil that thaws briefly during the summer
dynamic equilibrium
a system displaying unrepeated average states through time
negative feedback
an automatic response to change in an ecosystem which restores equilibrium
water table
the upper surface of the zone of saturation in permeable rocks and soil
water abstraction
removing water from a store e.g. aquifer
syncline
a downfolded, basin-like geological structure
artesian pressure
the pressure in an aquifer that, when tapped, pushes the water above the level of the aquifer, sometimes to the surface.
artesian aquifer
Confined aquifer containing groundwater that will flow upward through a well w/o a pump due to pressure
potentiometric surface
an imaginary surface that defines the theoretical level to which water would rise in a confined aquifer
carbon capture and storage
CCS - The process of trapping carbon dioxide produced by burning fossil fuels or any other chemical and storing it
positive feedback
an automatic response to change in a system which generates further change
greenhouse gas
gases in the atmosphere such as carbon dioxide, methane, nitrous oxide, water vapor, and ozone which are involved in the greenhouse effect.
carbon fertilisation
rising CO₂ levels in the atmosphere which increase photosynthesis and stimulate plant growth
diurnal change
daily cycle of change
seasonal change
annual cycle of change related to the seasons
net primary productivity
the rate at which plants accumulate energy in the form of organic matter taking into account the energy used in respiration (kg/m²/year)
photoperiod
length of day, i.e. from sunrise to sunset
glacial
a prolonged cold climatic phase lasting for tens of thousands of years and causing continental glaciation in middle and high latitudes
inter-glacial
a period of climatic warming (lasting c. 10,000 years) between glacials
cryosphere
referring to all water that is temporarily frozen in polar ice caps, snow, permafrost, and glaciers
wetland
an area of land that is covered with a shallow layer of water during some or all of the year
afforestation
Planting seeds or trees to make a forest on land that has not been a forest recently, or which has never been a forest.
reforestation
the replanting of previously degraded forest land
desertification
the reduction in agricultural capacity due to overexploitation or resources and natural processes such as drought. Only in extreme cases does this result in desert-like conditions
land degredation
the deterioration of land suitability for agriculture by soil erosion, desertification and salinisation
overcultivation
cultivation which, given environmental resources, is not sustainable in the long term and is evidenced by declining yields, soil exhustion and soil erosion
overgrazing
excessive grazing of land by livestock which destroys or degrades pasture and is not sustainable
cap and trade
Market-based system of emissions control whereby individual businesses can buy and sell emission credits even while the total level of industry emission is capped at some level
carbon credit
a permit that allows an organisation to emit a specified amount of greenhouse gases, also called an emission permit
carbon offset
A voluntary payment made to compensate for greenhouse gas emissions
What is a System?
-A model (A simplification of reality)
Where are Systems most commonly used?
-In Physical Geography
What does a system involve?
-a set of things related to each other- connected together to form a working unit
What is an Input?
-Addition of matter and/or energy
What is an example of an input?
-Energy from the sun in hydrological cycle
What is an output?
-Loss of matter and/org energy
What is an example of an output?
-Loss of water through evaporation from rivers in hydrological cycle
What is a flow?
-Movement of matter and/or energy from one store/component to another
What is an example of a flow?
-Water moved from the surface (store) to groundwater store, through infiltration in hydrological cycle
What do all systems have?
-series of stores/components that have flows (connections) between them which transfer energy and/or matter
-lies between a boundary
What is an Isolated System?
-Very rare in nature
-No interactions with anything outside the system boundary
What is an example of an Isolated System?
-Laboratory Experiments- enclosed and artificially controlled environment
What is a Closed System?
-Transfers energy but not matter across boundary to the surrounding environment
What is an example of a Closed System?
-The Earth
What is an Open System?
-Transfers both energy and matter across its boundary to the surrounding environment
What is an example of an Open System?
-Drainage Basin
What do Open Systems do?
-Adjust themselves to flows of energy and/or matter by modifying the interrelationships between different elements of the system so inputs and outputs are in balance
What is a Dynamic Equilibrium?
-Adjusting to balance inputs and outputs
What does Feedback mean?
-occurs when one element of a system changes due to outside influences
What is Positive Feedback?
-Change causes a snowball effect within the system
What is an example of Positive Feedback?
-Water cycle- sea levels rising- ice sheets melt more- further increase sea levels
What is Negative Feedback?
-Change reverses the effect of it
What is an example of Negative Feedback?
-Water cycle- increased sea surface temp- more evaporation- more cloud cover- reduce sunlight- reduces surface temps
What is water on Earth stored in?
-A cascading physical system
What is Hydrosphere?
-All the water on or close to the Earth’s surface
What is an example of Hydrosphere?
- Oceans, Seas, Rivers, Lakes, Aquifers, Soil, Clouds, Ice
What is Hydrosphere made up of?
-Atmosphere
-Cryosphere
-Lithosphere
What state is Atmosphere?
-Gaseous