1.1.1 Systems in physical geography

Question 1

What are systems?

Answer 1

A set of interrelated components working towards a process, which allows us to understand how certain processes work.

Question 2

What are the four components that systems have?

Answer 2

• Inputs
• Outputs
• Flows
• Stores

Question 3

Types of systems

Answer 3

• Isolated
• Closed
• Open

Question 4

Elements

Answer 4

Things that make up the system.

Question 5

Attributes

Answer 5

The perceived characteristics of the system.

Question 6

Relationships

Answer 6

How the various elements (and their attributes) work together to carry out a process.

Question 7

Inputs

Answer 7

When matter or energy enters the system.

Question 8

Outputs

Answer 8

When matter or energy leaves the system.

Question 9

Stores

Answer 9

Where matter or energy builds up.

Question 10

Flows (transfers)

Answer 10

When matter or energy moves from one store to another.

Question 11

Boundaries

Answer 11

The limits of the system.

Question 12

Give an example of a system (drainage basin)

Answer 12

Water enters as rain (input). The system’s watershed is the boundary. Some water is stored in the soil and vegetation. Water travels from the drainage basin to the river and then down the river (flows). It leaves the system where the river meets the sea (output).

Question 13

Open system

Answer 13

Where energy and matter can be transferred from the system and into/beyond the surrounding environment.

Question 14

Closed system

Answer 14

Where only energy transfers into and out of the system. They have no transfer of matter.

Question 15

Isolated system

Answer 15

No inputs or outputs and have no interaction with anything outside of the system boundary – Not found in nature.

Question 16

Give an example of a closed system

Answer 16

The carbon cycle is a closed system – energy is input (e.g. through photosynthesis) and output (e.g. respiration), but the amount of energy on Earth stays the same because there are no inputs or outputs of matter.

Question 17

Give an example of an open system

Answer 17

Drainage basins are open systems as energy from the Sun enters are leaves the system. Water is an input as precipitation and an output as river discharge into the sea.

Question 18

What is dynamic equilibrium?

Answer 18

Where 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 19

Positive feedback

Answer 19

Positive feedback mechanisms amplify the change in the inputs of outputs.

This means the system responds by increasing the effects of the change, moving the system even further from its previous state.

Question 20

Give an example of positive feedback

Answer 20

Question 21

Give an example of negative feedback

Answer 21

Question 22

Albedo effect

Answer 22

A positive feedback climate process where a change in the area of ice caps, glaciers and sea ice alters the albedo and surface temperature of a planet. Warming tends to decrease ice cover and hence decrease the albedo, increasing the amount of solar energy absorbed and leading to more warming.

Question 23

The Earth as a system

Answer 23

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 24

What are the subsystems which the earth is broken down into?

Answer 24

• Cryosphere
• Lithosphere
• Biosphere
• Hydrosphere
• Atmosphere

Question 25

Cryosphere

Answer 25

All the parts of the Earth’s system where it’s cold enough for water to freeze. For example, glacial landscapes.

Question 26

Lithosphere

Answer 26

The outermost part of the Earth. It includes the crust and upper parts of the mantle.

Question 27

Biosphere

Answer 27

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

Question 28

Hydrosphere

Answer 28

All the water on earth. It may be in liquid form (e.g. lakes or rivers), solid form (ice stored in cryosphere) or gas form (e.g. water vapour in the atmosphere). It can be saline (salty) or fresh.

Question 29

Atmosphere

Answer 29

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

Question 30

Relationship between the subsystems

Answer 30

• These subsystems are interlinked by key systems such as the water cycle and carbon cycle.
• Matter (e.g. water and carbon) and energy move between subsystems.
• Changes that occur in one subsystem can affect what happens in others.
• Earth is thought to be a “cascading system” as energy and matter move from one subsystem to the next.