1. (The flow of Earth’s waters)
Hydrologic Cycle
(The flow of Earth’s waters)

2. Objectives To be able to summarize Earth’s hydrologic cycle.
To be able to illustrate the carbon cycle.
To be able to discuss current issues related to the Earth’s hydrologic cycle.

3. Hydrological Cycle Video
Earth is unique, water exists here in all three states:
Solid
Liquid
Gas

4. Major Glacial Ice Sheets
Antarctica – Earth’s largest freshwater sink.
Greenland – Earth’s second largest freshwater sink (with Antarctica, they play a major role in Earth’s water cycle).
Himalayas – Third largest ice sheet. Important due to its role in providing water for billions of people.
Southern Andes

5. Southern Andean Ice Field - Chile

6. Perito Moreno – Argentina (Andes)

7. Himalayan Ice Sheet – 3rd largest in World

8. Qori Kalis - Himalayas

9. Greenland Ice Sheet

10. Antarctica

11. Antarctica

12. Glacier National Park – Montana (Our own backyard)
It has been estimated there were approximately 150 glaciers present in 1910 when the park was established. In 2010, we consider there to be only 25 glaciers larger than 25 acres remaining in GNP.

13. Glacier National Park

14. Diagram – Hydrologic Cycle
Advection - the transfer of heat or matter by the flow of a fluid, esp. horizontally in the atmosphere or the sea.

16. Vocabulary Evaporation Transpiration Evapotranspiration Sublimation
Advection
Condensation
Gulf Stream
Desertification
Runoff
Groundwater

17. Earth’s Water
Total volume of water on Earth is approximately 326 million trillion gallons.
That would be 20 decimals and (I looked this up) would be 326 quintillions.
Question: if Earth’s water could fit into a gallon container, what percent do you think would be available to us?
Think about the forms of water.

18. Changes in Hydrologic Cycle
Examples: change in Gulf Stream and desertification

19. Gulfstream

20. Gulfstream Infrared Satellite

21. How the Gulfstream Works
Of all the ocean currents, the Gulf Stream is one of the strongest. It brings warmth to Europe and North America. 
Surface water in the north Atlantic is cooled by winds from the Arctic.
It becomes more salty and more dense, which makes it sink to the ocean floor.
Cold water then moves towards the equator where it slowly warms.
To replace all this cold water, the Gulf Stream moves warm water from the Gulf of Mexico to the North Atlantic.

22. How the Gulfstream Works
Could global warming affect the Gulf Stream?
At the end of last Ice Age ended (10,000 years ago), huge amounts of ice melted.
Because the new freshwater, the water in the North Atlantic became less salty.
The ocean water in the North Atlantic was less dense, and did not sink.
This caused the Gulf Stream to shut down.

23. How the Gulfstream Works
Temperatures in north-west Europe fell by 5°C in just a few decades.
Something similar could happen today: an increase in global temperatures and precipitation could add a lot more freshwater to the north Atlantic.

24. If the Gulfstream Shuts Down
Implications
A reduced Gulf Stream - lower temperatures in northwest Europe and northeast US.
However, there is debate over whether the Gulfstream shutting down would protect northwest Europe or northeast US from elevated temperatures.
Most models say no.
Major ecological effects on marine life – and potential for major economic losses.

25. Gulf Stream Illustrate the Gulf Stream. Identify where it is.
How does the Gulf Stream current work?
What is the mechanism that moves the water?
What is the effect of the Gulf Stream?
What might change the Gulf Stream?

26. Desertification - Honduras

27. Desertification – as it progresses

28. Desertification

29. Not just a third world problem
Dust bowl – southern plains

30. High Water Stress Areas

31. How would you define desertification?
Take a minute and think about desertification.
With the pictures you have seen, define desertification.
Formal definition: "the process of fertile land transforming into desert typically as a result of deforestation, drought or improper/inappropriate agriculture“
In some cases desertification can be stopped and “revert back” to normal state.
The ecosystem changes need to be halted.

32. Question Can desertification cause climatic changes?
What might those changes be?
How could the hydrologic cycle be affected locally?
What would happen to the evaporation?
Transpiration?
Condensation?
Precipitation?
Infiltration of water to the water table?

33. Activity Illustrate the hydrologic cycle.
Identify all of the different components.
Indicate how they are related.
Make sure you identify the three phases of water and where they occur (where are the water sinks).