1. Ocean Water California Standards: 5d, 7b

2. Dissolved Gases
The two main gases in the atmosphere are oxygen and nitrogen.
These two gases are also the main gases in water.
Carbon dioxide is not a major gas in the atmosphere it is an important gas in the water.

3. Dissolved Gases The sources of gases in water come from
The land in rivers and streams
Underwater volcanoes, called seamounts and marine organisms
From the atmosphere

4. Seawater Composition Seawater is over 96 % pure water.
Salts make up less than 4 % of seawater.
The two major salts are:
Sodium, Na and Chloride, Cl.
These two elements make up over 85 % of salt water.

5. Seawater Composition
table salt = NaCl = sodium chloride

6. Source of Sodium Chloride
The salt in the oceans comes from three main sources.
1. Volcanoes add sulfur
2. Erosion from the land adds sodium, chloride, magnesium, calcium, etc.
3. The formation of seafloor through seafloor spreading

7. Salt Sources in the Ocean

8. Marine Life and the Mid-Atlantic Ridge
Where the sea floor opens up by sea-floor spreading magma heats up the water at deep oceanic ridges.
This hot water and minerals gives rise to bizarre creatures.
This hot water comes from ‘smokers’ deep under the ocean.

9. Vents at mid-ocean ridges
Smoker

11. Density of Ocean Water
Density is the mass of a substance per unit volume or grams per cubic centimeter.
The two factors which affect seawater density are:
1. Temperature and
2. Salinity or the amount of salt, specifically sodium chloride.

12. Temperature of Ocean Water
The location of ocean water, or latitude of the water determines how much solar energy it receives and therefore, its temperature.
The upper surface temperature of the ocean water stays fairly constant, but at a certain depth it changes drastically.

13. Ocean Temperature
Equator

14. Ocean Thermocline
The temperature at which ocean water changes very fast is called the thermocline.

15. Seasonal Ocean Thermocline

16. How would you describe the region between 300 and 700 meters?

17. Water Temperature and Density

18. Ocean Water Salinity
Ocean water has an average salinity from 3.3 % to 3.6% or to
As water evaporates the salinity increases because the salts are left behind in the water.
Therefore, the salinity along the equator is higher.

20. Seawater Density and Salinity

21. Density of Seawater in the Atlantic Ocean

22. Life in the Oceans Ocean life depend upon two factors for survival:
1. Nutrients and
2. Sunlight

23. Upwelling brings up nutrient rich water from the ocean bottom.

24. Marine Life Classification
Plankton: mircoscopic, free-floating organisms.
Nekton: Free swimming organism, fish, dolphins, and you and me.
Benthos: organisms that live on the ocean floor or bottom of the ocean.

26. Ocean Environment
The zone at the bottom of the ocean is called the benthic zone while
The zone in the upper portion of the ocean, or freshwater, is called the pelagic zone.

27. Pelagic Zone
Benthic Zone

28. The End