1. Water Cycle

2. Are you drinking the same water a dinosaur drank?
Could you be drinking the same water a saber tooth tiger lapped up?
What do you think? Is the water we have on earth today the same water that was here millions of years ago?
Water on earth moves in a continuous cycle. This is called THE WATER CYCLE. There is about the same amount of water on earth now that there was when the dinosaurs roamed our planet.

4. The cycle starts when the sun's heat provides energy to evaporate water from the surface. Then, winds lift the water vapor from the ocean over the lands into the atmosphere. The water vapor condenses to form clouds, and when the conditions are just right, the clouds release water as rain or snow. About 80% of the rain falls in the oceans, but the rest falls onto land. Rivers and streams collect water from the ground and return it to the ocean so the whole cycle can start all over again. The water cycle never ends because the salty ocean water constantly supplies fresh water to the continents.

6. One process which tranfers water from the ground back to the atmosphere is evaporation. Evaporation is when water passes from a liquid phase to a gas phase. Rates of evaporation of water depend on factors such as solar radiation, the temperature, humidity, and wind.
Water that is held in lakes and rivers evaporates directly into the atmosphere, but some of the water in the groung may also be returned to the atmosphere by way of evaporation through the soil surface. Of course, the ocean is the greatest source for water evaporated into the atmosphere.

7. Condensation is the change of water from its gaseous form (water vapor) into liquid water. Condensation generally occurs in the atmosphere when warm air rises, cools and looses its capacity to hold water vapor. As a result, excess water vapor condenses to form cloud droplets.

8. Precipitation is the main way for transporting water from the atmosphere to the surface of the earth. There are several forms of precipitation, the most common of which for the United States is rain. Other forms of precipitation include; hail, snow, sleet, and freezing rain.

9. Groundwater is all the water that has gone through the earth's surface and is found in one of two soil layers. The one nearest the surface is the "zone of aeration", where gaps between soil are filled with both air and water. Below this layer is the "zone of saturation", where the gaps are filled with water.

10. Transpiration is the process by which plants return water to the atmosphere. After absorbing water from the ground, plants release water through their leaves. Transpiration helps plants stay cool, in the same way perspiration keeps humans and animals cool.

11. Runoff is the movement of land water to the oceans, mostly in the form of rivers, lakes, and streams. Runoff consists of precipitation that hasn’t evaporated, transpired or penetrated the surface to become groundwater. Even the smallest streams are connected to larger rivers that carry billions of gallons of water into oceans worldwide.

12. water cycle looks like moving
Let's see what the
water cycle looks like moving
and complete a puzzle.

13. Let's find out what
would happen to two
water drops in the
water cycle.

14. The water cycle story starts as
the Sun looks down on 2 water drops....
I am hot and
full of energy!
It's getting
hot!
I feel light
and airy!
The Sun's heat provides energy to evaporate water from the Earth's surface (oceans, lakes, etc.).

15. You have
evaporated!
We're not floating
in the water! We
are water vapor!
I feel so
strange!
Evaporation occurs when heat is placed on water until the temperature becomes warm enough to change water into a gas.

16. It's water, but it's
a gas. We have
evaported. Let's
fly up high!
What is water
vapor?

17. Condensation is the cooling of water vapor until it becomes a liquid
Condensation is the cooling of water vapor until it becomes a liquid. As the dew point is reached, water vapor forms tiny visible water droplets. When these droplets form in the sky and other atmospheric conditions are present, clouds will form.
Let's join the
others and form
a cloud.
Okay, let's
condense.

18. I'm a beautiful
cloud. Is it getting
cold?
I think I'm
going to
snow.

19. I can't stop
falling. Where
are we going?
Down.
When the clouds meet cool air over land, precipitation (rain, sleet, or snow) is triggered, and water returns to the land (or sea).

20. We're stuck on
a glacier. A
river of ice!
Now I'm ice!
I hate this part
of the water
cycle!

21. We're only moving
1 foot a year. This
is so boooring!
It's so far
to the bottom!

22. A long, long, long time later, two very bored drops of water emerge from the bottom of the glacier.
Wow! We
finally melted!
We're a
stream!
Most of the water flows downhill as runoff (above ground or underground), eventually returning to the seas as slightly salty water.

23. Watch out
for the
waterfall!

24. We're in a
river.
It's getting
warmer.

25. We're in a
reservoir now.
Here we go down
the pipes.

26. They missed
us!
Oh no! We're
coming out of
the sink and
someones making
coffee!
                          
We're going
back down
the drain.
                            

27. Hi there!
Did you miss
me?
We're back
in the ocean.

28. I feel hot
and dizzy.
Here we go
again!