Natural Systems

Question 1

What are inputs?

Answer 1

When matter or energy is added to the system.

Question 2

What are outputs?

Answer 2

When matter or energy leaves the system.

Question 3

What are stores?

Answer 3

Where matter or energy builds up.

Question 4

What are flows

Answer 4

When matter or energy moves from one store to another.

Question 5

What are boundaries?

Answer 5

The limits of the system.

Question 6

What is matter?

Answer 6

Matter is any physical substance involved in a system.

Question 7

What are the open systems?

Answer 7

Both energy and matter can enter and leave an open system - there are inputs and outputs of both.

Question 8

What is an example of an open system?

Answer 8

A drainage basin 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.

Question 9

What are closed systems?

Answer 9

Matter can’t enter or leave a closed system it can only cycle between stores.
Energy can enter and leave a closed system it can be input or output.

Question 10

What is a example of a closed system?

Answer 10

The carbon cycles is a closed system - energy is input (from the sun by photosynthesis) and output (respiration), but the amount of carbon on Earth stays the same because there are no inputs or outputs of matter.

Question 11

What does it mean if the system is in equilibrium?

Answer 11

It means the inputs and outputs of a system are balanced, flows and processes continue to happen, but in the same way at all times, so there are no overall changes to the system.

Question 12

What does it mean if the system is said to be in dynamic equilibrium?

Answer 12

There are lots of small variations in the inputs and outputs of a system. These variations are usually small, so the inputs and outputs remain about balanced on average but is said to be in dynamic equilibrium.

Question 13

How would a new dynamic equilibrium happen?

Answer 13

If large long term changes to the balance of inputs and outputs can cause a system to change and establish a new dynamic equilibrium.

Question 14

What is a positive feedback and what does it mean for the system?

Answer 14

A positive feedback mechanisms amplify the change in the inputs or outputs.
This means the system responds by increasing the effects of the change, moving the system even further from its previous state.

Question 15

What is a negative feedback and what does it mean for the system?

Answer 15

Negative feedback mechanisms counteract the change in the inputs or outputs.
This means that the system responds by decreasing the effects of the change, keeping the system closer to its previous state.

Question 16

Is the Earth an open or closed system?

Answer 16

The Earth can be seen as a closed system - energy is input from the Sun and output to space, but matter is not input or output to space.

Question 17

How many subsystems can the Earth be broken down into?

Answer 17

5

Question 18

What is the Cryosphere?

Answer 18

The cryosphere includes all the parts of the Earth system where its cold enough for water to freeze, e.g. glacial landscapes.

Question 19

What is the Lithosphere?

Answer 19

The lithosphere is the outermost past of the Earth. It includes the crust and the upper parts of the mantle.

Question 20

What is the Biosphere?

Answer 20

The biosphere is the part of the earth’s system where living things are found. It includes all the living parts of the Earth - plants, animals, birds, fungi, insects, bacteria.

Question 21

What is the Hydrosphere?

Answer 21

The hydrosphere includes all of the water on Earth. It may be in liquid form (e.g. in lakes and rives), solid form (ice stored in the cryosphere) or gas form (e.g. water vapour stored in the atmosphere). It can also be saline (salty or fresh).

Question 22

What is the Atmosphere?

Answer 22

The atmosphere is the layer of gas between the Earth’s surface and space, held in place by gravity.

Question 23

What does a cascading system mean?

Answer 23

Because of the way that matter and energy move from one subsystem to the next, the Earth system is said to be a cascading system.