The Hydrosphere and Biosphere

1. The Hydrosphere and Biosphere

2. Life on Earth is restricted to a very narrow layer around the Earth’s surface. This layer is called the biosphere

3. In the biosphere, everything that organisms need to survive can be found One of these requirements of living things is liquid water

4. The Hydrosphere

5. The hydrosphere includes all of the water on or near the earth’s surface. It includes: • Oceans and seas • Lakes • Rivers • Wetlands • Ice caps

6. The continuous movement of water into the air, onto land and then back to water sources is known as the water cycle

7. Evaporation is the process by which liquid water is heated by the Sun and then rises to the air as water vapor Water continually evaporates from Earth’s oceans, lakes rivers, etc.

8. Condensation is when water vapor forms water droplets on dust particles The water droplets form clouds and possibly rain

9. Precipitation happens when larger water droplets fall from the sky as rain Precipitation may also fall as snow, sleet or hail

10. Earth’s Oceans

11. We talk about the oceans as if they were separate, but they are all connected We think of them as a world ocean

12. The Earth’s oceans include: • The Pacific – largest ocean 165 million square km. and an average 4200 m deep • The Atlantic – second largest • The Indian – third largest, average depth of 3900 meters • The Arctic – smallest ocean, much of the surface is covered with ice

13. The difference between ocean water and fresh water is that ocean water contains more salt The concentration of all the dissolved salts in the oceans is known as salinity

14. The ocean is divided into three layers depending on temperature • Surface zone – warm top layer, heated by the sun • Thermocline – water temperature drops with depth • Deep zone – the temperature averages 2 C

15. One of the most important functions of the oceans is to absorb and store energy Without the oceans, temperatures would be too extreme for life to exist

16. Fresh Water

17. A little more than 3% of the Earth’s water is fresh water Most of the fresh water is caught up in the ice caps and glaciers, while the rest is found in lakes, rivers, wetlands and soil

18. A river system is a network of streams that drains an area of land Smaller streams or rivers that flow into larger ones are called tributaries

19. Rain and melting snow sink into the ground and collects as groundwater Less than 1% of the earth’s water is found as groundwater

20. The Biosphere

21. The biosphere is the narrow layer around the earth’s surface in which life can exist It extends from 11km into the ocean to 9km into the atmosphere

22. Life exists on Earth because: • It has liquid water • It has the proper temperature (10 to 40C) • It has a source of energy (the Sun) • It has an atmosphere • It has materials for organisms to grow, and reproduce (carbon, oxygen, nitrogen)

23. The biosphere provides all the conditions necessary for life to exist

24. Energy is constantly being cycled and recycled through the biosphere When an organism dies, it decomposes and the nutrients become available for other organisms. The flow of energy allows life to exist

25. In a closed system energy enters a system but matter does not The Earth is mostly as closed system. Not much matter enters or leaves the Earth

26. In an open system, both matter and energy are allowed to enter and leave A tree is an example of an open system