1. Oceans ~ Continued 
Messana

2. Ocean Waters Contains NaCl, dissolved solids & gases (O2, N2, CO2)
Salinity = 35g salt/1000g seawater
Higher salinity = higher density of water
Objects are more buoyant in water that is more dense (Dead Sea – 10X saltier than ocean- >more dense ->humans more buoyant)

3. Buoyant Force vs. Gravity

5. 3 Layers of Ocean
1. Surface = warm water, less dense, coldest at poles, warmest at equator, m, 25 C
2. Thermocline = temperature drops fast as depth increases, 300 – 700 m, 25->5 C
3. Deep = cold all year, barely above freezing, 0-3 C

6. Ocean Currents
Currents = mass of moving water, distributes heat & nutrients
Surface Currents – caused by WINDS
Top 200 meters
Rotate different directions in each hemisphere
Pull warm water from equator & cold water from poles
Gulf Stream = surface current that moves water from the Gulf across Atlantic Ocean, northeastward toward Britain, makes climate there more mild
El Nino = change in surface currents in Pacific due to winds not blowing as strongly west across the Pacific, affects weather patterns globally

7. Surface Currents surrounding US

8. Ocean Currents
Deep Currents – caused by DIFFERENCES IN DENSITY (due to temperature & salinity)
1. Upwelling: movement of water up to surface, brings up nutrients, good for animal life
2. Downwelling: movement of water from surface to greater depths, carries O2 down, allows for life

9. Upwelling & Downwelling

10. Exploring the Ocean Floor
How can we overcome ocean obstacles to learn more?...
Pressure
Darkness
Lack of air
Cold
Wildlife

11. Exploring the Ocean Floor
Technology to use:
Submarines
Submersibles (Alvin)
Robots with cameras
Sonar = using sound waves to measure distances, depths, locate objects
Satellite Imagery – light waves from space

12. University of Miami Submersible

13. The Ocean Pearl

14. Sonar for measuring depth of ocean floor: