Natural Systems Flashcards
Define inputs.
When matter/energy is added into the system.
Define output.
Where matter/energy leaves the system.
Define store.
Where matter/ energy is builds up and is held.
Define flow.
When matter/energy transfers from one store to another.
Define a systems boundary?
The limits of a system.
Give an example of a system and name the inputs, outputs, flows, stores and boundaries.
The drainage basin system:
Input- precipitation (rainfall)
Boundary: watershed
Store: soil through infiltration
Flow: water travelling down the river
Output: when the river meets the sea
Define open system.
When both energy/matter can leave and enter the system. Eg: drainage basin.
Define closed system.
What matter/energy cannot enter or leave the system (cycle)
Eg: carbon cycle.
Define a system equilibrium.
When a systems inputs and outputs are equal so there are no changes to the system overall.
Define a system in dynamic equilibrium.
When the systems inputs and outputs vary slightly.
Bigger changes can lead to positive or negative feedback.
Define positive feedback.
When changes in the system amplify the result of the inputs and outputs.
E.g: Global warming.
How is global warming an example of positive feedback?
Temperature rises
Glaciers melt due to high temp
Less ice means less sun energy reflection
More sun energy absorbed by earth.
(Back to the start)
Define negative feedback.
When changes in the system counteract the change in inputs or outputs.
Eg: increased CO2 means more plant growth.
Why would CO2 being released into the atmosphere be negative feedback?
More CO2 emission
= more in atmosphere
Extra CO2 causes more plant growth
Plants remove CO2 from atmosphere
= less CO2 in atmosphere
What is the cryosphere?
The parts of Earth where water freezes
Eg: glacial landscapes.
