1. Chapter 14.1 The Vast World Ocean

2. The Blue Planet  71% of Earth’s surface is covered by the ocean.  Oceanography – the study of the ocean.

3. Geography of the Oceans  There are 4 main ocean basins that make up the world ocean – the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, and the Arctic Ocean.

4. Pacific Ocean  The largest ocean – covers more than ½ of the ocean surface on Earth.  It is also the deepest ocean at 3,940 m.

5. Atlantic Ocean  ½ the size of the Pacific Ocean and not quite as deep.  It is a relatively narrow ocean.  Both Atlantic and Pacific Ocean are bounded by continents.

6. Indian Ocean  Slightly smaller than the Atlantic Ocean, but the same depth.  It is located almost completely in the southern hemisphere.

7. Arctic Ocean  Is only 7% the size of the Pacific Ocean.  It is also only a little more the ¼ as deep as the rest of the oceans.

8. Mapping the Ocean Floor  The ocean floor has many features like chains of volcanoes, tall mountain ranges, trenches, and large submarine plateaus.  Bathymetry is the measurement of ocean depths and charting the shape or topography of the ocean floor.  The first mapping of the sea floor was the Challenger from December 1872 to May 1876.  They measured the floor by lowering a long, weighted line overboard.  Today we have better technology like sonar, satellites, and submersibles to study the ocean floor.

9. Sonar  Sonar is an acronym for sound navigation and ranging.  Sonar works by releasing sound waves toward the bottom of the ocean and measuring when the echo returns.  There is now multibeam sonar that allows the ocean floor to be mapped in a narrow strip.

10. Satellites  Satellites can measure small differences in height caused by ocean floor features that the human eye cannot pick up.

11. Submersibles  A submersible is a small underwater craft used for deep-sea research.  They can be equipped with many different instruments like thermometers, cameras, and pressure gauges.  Water samples can be taken with submersibles as well as sediment samples.  The first submersible was in 1934.  Submersibles can be manned or unmanned, remotely operated vehicles (ROV’s).