1. Label the Ocean Floor L. A. D. K. C. H. G. B. E. F. J. I.

2. Active Continental Margin
Trench is formed from subduction of plate
Ex: West coast of South America

3. Passive Continental Margin
No plate boundary, so no subduction
Ex: East coast of United States

4. How do we know what it is like?
Ocean Exploration
How do we know what it is like?

5. HMS CHALLENGER First scientific attempt to measure depth of
ocean around the world
Old Method – rope & weight used to measure
took 3 ½ years to complete.

6. Studying the Ocean Floor
SONAR - Sound Navigation And Ranging
Uses echolocation like bats and dolphins
Sound Wave travels through water and bounces back when it hits solid earth
The time it takes for the sound to travel is used to calculate the distance (depth) of the ocean floor
Makes a bathymetric profile (map)

7. Satellites
Seasat measured direction and speed of currents
Geostat – measures changes in water heights to make maps of the ocean floor since ocean features affect the height of the water above them

8. Under Water Vessels: Alvin – discovered hydrothermal vents
Deep Flight – moves
like airplane
Jason II – “flown”
remotely from surface
Medea – attached to Jason II to explore just above sea floor
PILOTED
Deep Flight
ROBOTIC

9. September 2013
From NPR:
“The newly revealed Tamu Massif volcano — located about 1,000 miles east of Japan and 4 miles below the ocean's surface — is about the size of New Mexico. It not only outclasses previous record holder Mauna Loa in Hawaii by about 60 times, but it's in the same league as Olympus Mons on the planet Mars, the largest known volcano in the solar system.”

10. Why Are we Ignoring the Oceans?