1. Chapter 13
Exploring the Oceans

3. Pangaea broke apart to form our oceans that we have today.
The first oceans began to form sometime before 4 billion years ago, as the Earth cooled enough for water vapor to condense and fall as rain.

4. WATER!
In addition to being vital to life, water plays a significant role in many of Earth’s processes. Almost 80% of Earth is covered by water.
Salt water makes up 97% of all the water on Earth
2% is frozen in ice caps and glaciers
1% is fresh water. (This is the only water humans can drink).

5. Water is a Natural Resource!
Because fresh water must be used for other human activities like farming, we must practice conservation of fresh water.
There is a limited supply of fresh water on Earth.
In times of drought, where there is little rain, humans need to make plans to conserve water, such as not watering lawns or filling up their swimming pools.

6. 71% of the Earth is WATER!

7. 97% of the water on Earth is salt water.

8. Why is it salty?
When water drains from land it weathers rock and dissolves minerals, carrying them to the ocean.
At the same time, water is evaporating from the ocean, leaving behind the solids.

9. Ocean Currents
A current is the continuous flow of ocean water. Currents can be described as either surface currents or deep-ocean currents.
Many forces act on the flow of these currents.
Waves, caused by the wind, act on surface currents
Differences in density, in temperature, and in salinity all have an impact on the flow of deep-ocean currents

10. Sodium and chlorine are the two most abundant elements in the ocean.
This makes sodium chloride (NaCl) the most abundant compound in the ocean.

11. Salinity The amount of dissolved solids in a given amount of liquid.
Which has a higher salinity? OR

12. Salinity of the Ocean
Do you see any patterns?

13. Climate affects salinity.
Temperature affects the evaporation rate, so the water has a higher salinity.
Ocean water has a lower salinity at the mouth of rivers because there is more fresh water.

14. The Ocean Holds Heat
The ocean absorbs and loses heat much slower than dry land. This helps the earth hold its steady temperature.

15. Why is the ocean warmer near the equator?

16. Heat Travels
The ocean also helps regulate temperatures in other parts of the world.

17. Tides
Tides are caused by the gravitational pull from the Sun and Moon on the ocean water.

18. Waves
Waves are created when wind moves across the surface of water and pushes the water. The energy from the wind is transferred to the water.
Waves can also be created when the energy from the waves created by earthquakes is transmitted to the water in the oceans.

19. Why are oceans salty?
The amount of salt in the ocean, also known as salinity, is largely caused by the runoff from rivers and streams that carry minerals into the oceans.
Salt is a mineral and can be found in soil and rocks.
The runoff of water has carried and continues to carry salt into the ocean.

20. Salt Water Salt water is dangerous for humans to drink.
Our bodies have a safe level of salts in them. When people drink salt water, their body will try to get rid of the excess salt by making more water leave their body, mostly through urine.
This is why you should never drink salt water when stranded at sea. You may be thirsty, but by drinking salt water, you will make yourself thirstier. Without enough water, your cells and organs cannot function properly.

21. The Water Cycle
The water cycle is the process that moves water above, below, and around the Earth in a cycle. The water cycle has four main stages:
Evaporation
Condensation
Precipitation
Collection

22. The Water Cycle
The Sun heats up liquid water and causes it to evaporate.
The water vapor, which is a gas, then rises up into the atmosphere.
When atmospheric conditions are right, the water vapor forms clouds as it cools. The clouds then release water as precipitation, in the form of rain and snow.

23. As the water runs off, it is collected into the ground and bodies of water.
The Sun then heats the liquid water up, causing it to evaporate and the water cycle starts all over again.

24. The Ocean Floor
Chapter 13

25. Ocean Topography
The subsurface topography of the ocean describes the features of the ocean floor.
Much like there are hills and valleys on land, the ocean floor is composed of many geological features.
There are flat valleys where sediment is deposited as it is eroded from rivers.
There are mountains on the ocean floor. There are valleys and very deep trenches that are thousands of kilometers long.
There are also active and inactive volcanoes.

26. The Ocean Floor

27. Seeing by SONAR SOund Navigation And Ranging
A ship sends sound waves to the ocean floor.
The sound waves bounce off the floor and back to the ship.
The deeper the water, the longer it takes for the sound waves to return.

29. Another way to study the ocean floor is with satellites.

30. The Ocean Floor

31. Continental Shelf
Begins at the shoreline and slopes gently toward the open ocean.

32. Continental Slope
Begins at the edge of the continental shelf and continues down to the flattest part of the ocean floor

33. Continental Rise
Made of large piles of sediment and found at the base of the continental slope

34. Can you find the continental Shelf, slope and rise?

35. Abyssal Plain
Broad flat part of the ocean that is very deep and covered with mud and the remains of decomposing organisms

36. Mid-Ocean Ridge
Mountain chains that form when tectonic plates pull apart at divergent boundaries

37. Rift Valley
The valley that forms when tectonic plates separate

38. Seamounts
Mountains of volcanic material that do not build up enough to break the surface
Seamounts

39. Ocean Trench
Large cracks in the ocean floor that form at convergent boundaries

40. Can you find all of the following:
Continental Shelf
Continental Slope
Continental Rise
Abyssal Palin
5. Mid-Ocean Ridge 6. Rift valley 7. Seamounts 8. Ocean trench