Natural Systems

Question 1

What are the Keywords for Systems?

Answer 1

Inputs 
Outputs 
Stores
Flows 
Boundaries 

E.g
In the water system water enters a drainage basin system as rain, the systems watershed is its boundary, an output is the channel flow, Some water is stored in vegetation and a flow could be evaporation.

Question 2

What is an open or closed system?

Answer 2

Open systems:
Both energy and matter can enter and leave an open system. E.g Drainage basins are open systems, energy from the sun enters and leaves the system, Water is input as precipitation and output as river discharge into the sea.

Closed systems: Matter can’t leave but energy can. E.g the Carbon cycle, energy is input from the sun but the amount of carbon on earth stays the same because there are no inputs or outputs of matter.

Isolated systems (neither matter or energy can enter or leave) can also be found but not in nature)

Question 3

What is Dynamic equilibrium?

Answer 3

Dynamic equilibrium is when lots of small variations in the short term can affect the balance but overall they average out to a long term average.

Question 4

What is a positive and negative feedback?

Answer 4

Positive feedback amplifies a change in inputs or outputs, the system therefore responds by increasing the effects of change moving the system even further from its previous state.

E.g; Temperatures rise ➡️ Ice coveting parts of earth melts due to higher temperatures ➡️ Less ice cover means less of the suns energy is reflected ➡️ Temperatures rise

Negative feedback counteract the change in the inputs or outputs, keeping the system closer to its previous state

E.g Large amounts of CO2 emitted ➡️ Extra CO2 causes increased plant growth ➡️ Increased Photosynthesis removes more C02 ⤵️ Amount of C02 decreases.

Question 5

What are the 5 subsystems of Earth?

Answer 5

CRYOSPHERE - Includes all of the frozen areas of Earth e.g Icecaps and glacial landscapes.

LITHOSPHERE - Outermost part of Earth including the crust and upper parts of the mantle.

BIOSPHERE - The part of the Earth where all of the living systems are including plants, animals and bacteria.

HYDROSPHERE - Includes all of the water on earth including the ocean, water vapour and Cryosphere.

ATMOSPHERE - Layer of gas coating the earths crust, held in place by gravity.