1.1 - Natural Systems Flashcards
What does a system consist of?
Stores Flows Boundaries Input Outputs
Definition Input
When matter of energy is added to a system
Definition Output
When matter or energy leaves the system
Definition Stores
When matter or energy builds up
Definition Flows
When matter or energy moves from one store to another
Definition Boundaries
The limits of the system
Example of a system
In a drainage basin system.. input- rain boundary - watershed stores - in vegetation flows- down the river output - river meets the sea
What is an open system?
both energy and matter can enter and leave an open system- inputs and outputs
drainage basins are open systems
What is a closed system?
matter can’t enter or leave a closed system- only cycle between stores
energy can enter and leave - input or output
carbon cycle is a closed system
what has to be balanced to make the system in equilibrium
inputs and outputs
what is it when a system is in dynamic equilibrium
when there is a little variation in the inputs and outputs within a system, they remain balanced on average
Explain positive feedback
mechanisms amplify the change in the inputs and outputs
system responds by increasing the effects of the change moving it further from its previous state
Example of positive feedback
temperature rises
ice melts due to the higher temperatures
less ice, less reflection
less reflected, more absorbed by the earth
Explain negative feedback
mechanisms counteract the change in the inputs and outputs
system responds by decreasing the effects of the change, keeping the system closer to its previous state
Example of negative feedback
large amounts of co2 emitted co2 in the atmosphere co2 causes plants to increase growth plants remove and store more co2 amount if co2 in the atmosphere decreases
