The Hydrosphere

•Liquid

• Surface water

• Underground water

•Ice

• Poles

• Icebergs

• Permafrost

•Vapour

• Atmosphere

TB pg. 227

• Living organisms depend on it.

• Bodily structure of living organisms (cells, transport, dissolve)

• Drinking purposes

• Habitat for plants and animals

• Photosynthesis

• Cleaning

• Cooking

• Transport etc.

TB pg. 228

• Also known as the hydrological cycle.

• This is the continuous movement of water on, above and under the ground.

• Water is recycled.

• Water is purified

• Provides fresh water.

What is it?

Why is it necessary?

TB pg. 228-229

Clouds droplets combine –become heavier and bigger

Precipitates: dew, hail, rain, snow

Forms water droplets –condenses by cooler temperatures

1.

2. 3.

4.

5.

TB pg. 228-229

evaporation

transpiration

condensationprecipitation

run-off

percolation

TB pg. 230

•Of the earths’ water: * 97% is salt water found in oceans

* 3% is fresh water

TB pg. 231

•Of the fresh water: * 68.7% is found in the ice caps at the poles and glaciers

* 11% is ground water

* 0.9% is other forms

TB pg. 231

•Of surface water: *87% from lakes

* 11% from marshes

* 2% from rivers

TB pg. 231

•A place where water is stored on earth

TB pg. 231

Let’s see what you know….

What is the hydrological cycle?

TB pg. 228

Let’s see what you know….

What is precipitation?

TB pg. 230

Let’s see what you know….

Give 4 examples of precipitation

TB pg. 230

Let’s see what you know….

What is evaporation?

TB pg. 230

Let’s see what you know….

What is transpiration?

TB pg. 230

Let’s see what you know….

Why is water important?

TB pg. 228

Let’s see what you know….

1.

2.

3.

4.

5.

6.

TB pg. 228

HomeworkExercise 26 pg. 232 - 234

1. Lithosphere - Land

- Solid rocks on crust

- Semi solid rocks under crust

- Hot fluid rocks near centre of earth

- Solid iron core

TB pg. 235

Systems of the earth2. Hydrosphere - All water in solid, liquid and gas

form.

TB pg. 235

3. Biosphere - All living organisms on earth.

TB pg. 235

4. Atmosphere - All gaseous components of the earth.

TB pg. 235

The spheres all affect one another

NATURAL INTERVENTION

• Earthquakes• Hurricanes• Tsunamis• floods

TB pg. 235

The spheres all affect one another

• Air pollution• Fires

• Oil pollution

HUMAN INTERVENTION

TB pg. 235

hydrosphere atmosphere

biospherelithosphere

• Water flows over ground.

• Soil erosion

• Precipitation

• evaporation

• Birds

• breathing

• Live and

grow on

ground

TB pg. 236

• Sun heats the land, sea and atmosphere.• The difference in temperatures and densities of air causes

wind.

• Sunlight and wind speeds up the process of evaporation.• This causes the rest of the water cycle to speed up.

•Water vapour absorbs sunlight and heat

1.

2.

3. TB pg. 237

•Water vapour absorbs sunlight and heat

• Water vapour is a greenhouse gas.

• A greenhouse gas is a polar molecule that absorbs the heat near the surface of the earth and reflects it back.

• Greenhouse effect: The reflected energy heats up the earth and is trapped in the atmosphere.

• This is natural as necessary. It ensures for a moderate climate.

• Without this the average temperature would drop from 15◦ 𝐶 to -15 ◦ 𝐶.

3. TB pg. 237

TB pg. 238

• Rain has a naturally

acidic pH of about 5.6

because of the presence

of gases in the atmosphere.

• High levels of air pollution means there is a

greater presence of dissolved gases.

• The pH decreases and results in acid rain.

• Acid rain damages plants soil, buildings and

statues.

TB pg. 238

biosphere

Surface tension

1.

• Every water molecule is attracted to

every other water molecule.

• The top layer of water molecules

attract one another more strongly forming a layer on the surface.

• Examples:• Spiders can walk on water

• Water droplets form on a leaf TB pg. 238

biosphere

Capillary action2.

• Water rises against gravity on the

inside of a thin tube.• Water molecules are more attracted to

the molecules of a tube than they are

to each other.• Examples:

• Water moves up the inside of the

straw.• Water rises in plants.

TB pg. 238

biosphere

Density of ice and water3.

• Density of water is dependant on its

temperature.• Cooler : More dense.

• At 4◦C and less – becomes less dense.

• This is because the strong hydrogen bonds form an open

hexagonal shape. TB pg. 239

pH of the ground1.

• Soil contains basic elements like 𝐶𝑎2+ ,𝑀𝑔2+, N𝑎+, 𝐾+ .

• It becomes more acidic when 𝐻+

are added.

• Soil in areas with high rainfall are

more acidic than those in drier areas.

lithosphere

TB pg. 239

permafrost2.

• Soil/rocks that are below O◦C for

more than 2 years.

• When permafrost thaws it can lead

to:

• Landslides• Damage to buildings

• Erosion

lithosphere

TB pg. 239

• Earth dams: Made by blocking streams and rivers with walls made of rocks and earth.

• Control dams: Used to prevent flooding.

• Reservoirs: Water stored for use.

• Hydroelectric dams: Used to generate electricity.

EXAMPLES

TB pg. 240

•Disturbance of plant and animal life.

•Vegetation in the rivers changes.

•Erosion and deepening of river beds.

•Silting up of dams.

•Altering the temperature of the water.

•Stops fish migration.

•Development around dams.

TB pg. 240

Let’s see what you know….TB pg. 235

Spheres of the earth

?

?

?

?

HomeworkExercise 27 pg. 243-247