1. Ocean Water
Ch. 15

2. What percent of the Earth’s surface is covered by Oceans?
70%!

3. Earth has four Oceans

4. Which one is the largest?
Covers 30% of surface of the Earth

5. Which one has the longest distance North to South?

6. Which one is mostly in the Southern Hemisphere?

7. Which one is the smallest?
And mostly in the Northern Hemisphere

8. Ocean water is a mixture of gases and solids dissolved in water
4% dissolved elements:
Cl, Na, Mg S, Ca, K
96% PURE WATER

10. Salinity A measure of dissolved solids in sea water
Number of grams of dissolved salts in 1 kilogram of water
Evaporation and freezing increases salinity

12. Salinity with depth:

13. What two substances are the most abundant in Ocean Water?
Chloride
Sodium

14. Salts and other materials in ocean water come from:
Volcanic activity in oceans
Erosion of land areas by rivers
Wave action along the shoreline

15. Density of Ocean Water:
Density is the mass of a substance per unit volume

16. Two factors affect density
1. Salinity
- Dissolved solids make ocean water more dense than fresh water
2. Temperature
- Cold water is more dense than warm water

17. Most abundant gases dissolved in ocean water:
Nitrogen (N2)
Carbon Dioxide (CO2)
Oxygen (O2)

18. CO2 dissolves most easily
Cold water holds more dissolved gases
Warm water holds less dissolved gases
Think of a pot of water on the stove – what is coming out as the temperature rises???
GASES! (oxygen)
The warmer the water, the less gas it holds!

19. The dissolved gases are recycled back into the air
The dissolved solids do not leave, they are used by living things in the sea.

21. Temperature of Ocean Water
Ocean water has ability to absorb sunlight which heats the water

22. Layering of water by temperature:

23. Surface zone (mixed layer):
Water temp higher at surface because of direct sunlight
Waves and currents mix surface water and transfers heat downwards
Extends meters
Warmer at equator than at poles
Only place where enough light is present to grow marine plants

26. Thermocline: Zone of rapid temperature change
Warmer water on top of layer
Colder, denser on bottom of layer

27. Area of very cold water that
Deep zone:
Area of very cold water that
extends meters

28. COLOR of the Ocean
The color of the ocean is determined by the way it absorbs or reflects sunlight. Much of the sunlight penetrates the surface of the ocean and is absorbed by the water.

29. light are the last color
Blue wavelengths of
light are the last color
to be absorbed

30. COLOR of the Ocean
In clear ocean water, blue light can penetrate up to 100 m before being absorbed. Until it is absorbed, it is reflected and makes the upper layers of ocean water appear BLUE.

31. At times it will look like other colors depending on what particles are in the water (ex. rocks, animals, etc.)
No wavelength of light can penetrate beyond 200 meters, so beyond that it is DARK.

32. Upwelling
process in which surface water moves farther out into the ocean and deep water moves upward to replace the surface water

35. Observe how upwelling occurs.