Marine Science Ocean Geography Notes

1. The Ocean Floor

2. How do we study the ocean floor?
 A variety of vessels, buoys,
and submersibles that use
sonar
 Manned submersibles that
can reach the ocean floor

3. Oceanic Crust
 Denser than continental crust
 Younger than oceanic crust
 Created at mid-ocean ridges
 Destroyed at subduction zones

4. Mid Ocean Ridge
 New crust created here
 Evidence seen in:
 Crustal age samples that show
symmetry on both sides
 Symmetrical paleomagnetism evidence
on both sides

5. Subduction Zone
 Old crust destroyed here
 Denser ocean crust goes under less
dense continental crust and is melted
within the mantle

6. Trench
 Extremely deep regions of the ocean

7. Continental Shelf and Slope
 Shelf – shallow extension of the continent; from a few to a
thousand kilometers from shore
 Slope – a steep drop off that marks the end of continental crust

8. Abyssal Plain
 Flat region beyond the continental slope where sediments and
remains of dead organisms accumulate

9. Volcanic Island Arc Via Subduction
 Volcanic island chain created by the rising magma formed from
the subduction of oceanic crust

10. Volcanic Island Arc Via Hot Spot
 Volcanic island chain created by a stationary magma source on a
tectonic plate moving about the hot spot