1.1.2 The water cycle

Question 1

How much water does the hydrosphere contain?

Answer 1

1.4 sextillion litres of water

Question 2

Most of water in the hydrosphere is ………… .

Answer 2

saline

Question 3

How much of the water in the hydrosphere is freshwater?

Answer 3

Less than 3%

Question 4

How much of the Earth’s freshwater is frozen in the cryosphere?

Answer 4

69%

Question 5

How much of the Earth’s freshwater is stored underground in the lithosphere?

Answer 5

30%

Question 6

How much of the Earth’s freshwater is stored as liquid freshwater?

Answer 6

0.3%

Question 7

How much of the Earth’s freshwater is stored as water vapour in the atmosphere?

Answer 7

0.04%

Question 8

What must water be in order for humans to be able to use it? What is a consequence of this?

Answer 8

• Must be physically and economically accessible
• Only a small amount of water on the planet can be used by humans

Question 9

For water to boil or melt, it has to ………… energy (e.g. from the Sun).

Answer 9

gain

Question 10

For water to condense or freeze, it has to ………… energy.

Answer 10

lose

Question 11

The global hydrological cycle is a ………… system.

Answer 11

closed

Question 12

Why is the global hydrological cycle a closed system?

Answer 12

There are no inputs or outputs of water.

Question 13

The amount of water present in each store varies over a range of scales from ………… to ………… .

Answer 13

local, global

Question 14

What does the magnitude of each store depend on?

Answer 14

The amount of water flowing between them

Question 15

Different flows occur at a range of …………. and ………… scales.

Answer 15

spatial, temporal