1. Exploring Our Oceans

2. 4 Oceans Atlantic Pacific Indian Arctic
Pacific is the largest and deepest ocean

3. Ocean Basics
A sea is a part of an ocean that is nearly surrounded by land.
Through the water cycle, the ocean is a source of fresh water.
Ocean water is a mixture of gases and solids dissolved in pure water.

4. Ocean Basics Oceanographers study the ocean
85 elements have been discovered in the ocean
Ocean is 96% pure water

5. Why Is the Ocean Salty?
Sodium Chloride is most abundant salt in the ocean
SALINITY—the amount of dissolved salts
Volcanic action is one source of dissolved materials. Erosion and weathering are the other sources.
Main reason that ocean is so salty is because water washes over rocks containing sodium chloride

6. Why So Salty?
As water flows over the rocks, the water picks up some of the salt and carries it into the oceans.
When water evaporates it leaves the salt behind.
Areas with more evaporation have more salt content
Salinity of the ocean is about 3.5%
One kilogram of ocean water contains about 35 grams of salt

7. Effects of Salinity
Because of the high salt content ocean water does not freeze until the temperature drops to about -1.9oC
Salt water has a higher density than fresh water
Water tends to be less salty as you move towards the surface of the ocean

8. Temperature of Ocean Water
Temperatures at the surface of the ocean vary with the location and the seasons
The broad surface of the ocean absorbs energy from the sun
Warm water is less dense than cold water, therefore warm water is found closer to the top
The farther down in the ocean you travel, the colder it gets

9. Changes in Depth
As you descend from the surface to the ocean floor, you pass through a section of the ocean called the WATER COLUMN

10. Depth… As you go down in the ocean: Temperature Decreases
Sunlight Decreases
Animal/plant life decreases
Salinity INCREASES
Pressure INCREASES
At bottom of the ocean, the water pressure is about 400 times greater than air pressure on Earth’s surface!!

11. Parts of the Ocean Main Parts Shore Line Continental Shelf
Continental Slope
Mid-Ocean Ridge
Abyssal Plain

12. Parts of the Ocean Shore Line—boundary between land and the ocean
Continental Shelf—part of the continent that extends into the ocean
Continental Slope—Goes from the edge of the continental shelf to the flatter part of the ocean floor

13. Parts of the Ocean Mid-Ocean Ridge—Mountain ranges under the ocean
Abyssal Plain—Large flat areas on the ocean floor
Seamounts—underwater mountains
Guyots—flat-topped seamounts

14. Parts of the Ocean
Trenches—long, narrow crack on ocean floor (Deepest part of the ocean)
Reefs—Limestone rocks made from shells and animals
Fringing Reefs—touch the shoreline of a volcanic island
Barrier Reefs—separated from shore by a lagoon
Atoll—surrounds an island that has been worn away

15. Ocean Zones Intertidal Zone Neritic Zone Bathyal Zone Abyssal Zone
Region between the low and high tides
Neritic Zone
Extends from the high tide to the edge of the continental shelf
Bathyal Zone
Region at the continental slope and extends down about 2000 meters
Abyssal Zone
From 2000 meters to about 6000 meters (ocean floor)

16. Ocean Resources Oceans are used for a variety of resources Food
Commercial Fishing
Big in NC, however has lead to overfishing in some ocean areas
Mineral resources
Oil and natural gas
Large deposits of these have been found
Offshore wells and drilling