1. Oceanography

2. What is Oceanography?
Oceanography is the study of the
Earth’s oceans

3. The Blue Planet Oceans contain 97% of water found on Earth.
Oceans cover 71% of the Earth’s surface.
4 Oceans: Pacific, Atlantic, Indian and Arctic
Average depth of oceans is 3800 meters – but light does not penetrate past 150 meters.

4. Seawater About 96.5% water and 3.5% dissolved salts (mostly NaCl)
Salinity is the measure of the amount of dissolved salts in seawater.
Since salt molecules are heavier than water molecules, saltwater is more dense than freshwater.

5. Ocean Layers
Temperature gets colder as you go down (deep ocean water is always COLD)
Cold water is more dense than warm water.

6. Ocean Movements
A wave is a rhythmic movement that carries energy through space or matter (ocean water).
waves are generated by wind.
As a wave passes, the water moves up and down in a circular pattern – only the energy moves forward.

7. Wave Characteristics

8. Parts of a Wave Crest – Highest Point Trough – Lowest Point
Wave Height – Distance between crest and trough
Wavelength – distance between two crests or two troughs

9. As waves reach shallow water near shorelines, waves lose energy due to friction along the ocean bottom.
This causes waves to slow down
Incoming wave crests catch up with the slower wave crests ahead.
Wavelength decreases – incoming waves become higher, steeper and unstable and the crest falls forward.
Collapsing waves are called breakers.

10. Tides Tides are the periodic rise and fall of sea level.
The highest level to which water rises is called high tide and lowest level is low tide
The difference in high and low tide levels vary from place to place (1 m to 15 m)
A daily cycle of high and low tides take 24 hours and 50 minutes.
                                                                                                                       

11. Types of Tides
Diurnal
Semi Diurnal
Mixed