The Hydrosphere
TB pg. 227 Liquid Surface water Underground water Ice Poles Icebergs Permafrost Vapour Atmosphere
TB pg. 228 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. 228-229 What is it? Also known as the hydrological cycle. This is the continuous movement of water on, above and under the ground. Why is it necessary? Water is recycled. Water is purified Provides fresh water.
Forms water droplets condenses by cooler temperatures Clouds droplets combine become heavier and bigger TB pg. 228-229 Precipitates: dew, hail, rain, snow 5. 3. 2. 1. 4.
precipitation TB pg. 230 condensation run-off transpiration evaporation percolation
TB pg. 231 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
A place where water is stored on earth TB pg. 231
TB pg. 228 Let s see what you know. What is the hydrological cycle?
TB pg. 230 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. 228 Let s see what you know. hy is water important?
et s see what you know. TB pg. 228 2. 1. 6. 3. 4. 5.
Homework Exercise 26 pg. 232-234
TB pg. 235 1. Lithosphere - Land - Solid rocks on crust - Semi solid rocks under crust - Hot fluid rocks near centre of earth - Solid iron core
Systems of the earth TB pg. 235 2. 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 HUMAN INTERVENTION Air pollution Fires Oil pollution
TB pg. 236 hydrosphere Precipitation evaporation atmosphere Water flows over ground. Soil erosion Birds breathing lithosphere Live and grow on ground biosphere
1. 2. 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. 3. Water vapour absorbs sunlight and heat TB pg. 237
3. Water vapour absorbs sunlight and heat Water vapour is a greenhouse gas. TB pg. 237 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.
TB pg. 238
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.
Examples: Spiders can walk on water Water droplets form on a leaf TB pg. 238 1. biosphere Surface tension 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.
2. Capillary action biosphere 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
3. biosphere Density of ice and water 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
1. ph of the ground lithosphere Soil contains basic elements like Ca 2+, Mg 2+, Na +, K +. It becomes more acidic when H + are added. Soil in areas with high rainfall are more acidic than those in drier areas. TB pg. 239
TB pg. 239 2. permafrost Soil/rocks that are below O C for more than 2 years. lithosphere When permafrost thaws it can lead to: Landslides Damage to buildings Erosion
Earth dams: EXAMPLES Made by blocking streams and rivers with walls made of rocks and earth. Control dams: Used to prevent flooding. Reservoirs: Water stored for use. TB pg. 240 Hydroelectric dams: Used to generate electricity.
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. TB pg. 240 Development around dams.
TB pg. 235 Let s see what you know.?? Spheres of the earth??
Homework Exercise 27 pg. 243-247