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Chapter 14

Chapter 14. The Ocean Floor. Section 14.1. The Vast World Ocean. The Vast World Ocean. The “Blue Planet ” or “Water Planet” Nearly 71% of Earth’s surface is covered by the global ocean.

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Chapter 14

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  1. Chapter 14 The Ocean Floor

  2. Section 14.1 The Vast World Ocean

  3. The Vast World Ocean • The “Blue Planet” or “Water Planet” • Nearly 71% of Earth’s surface is covered by the global ocean. • Oceanography – is a science that draws on the methods and knowledge of geology, chemistry, physics and biology to study all aspects of the world ocean.

  4. The Vast World Ocean

  5. The Vast World Ocean • Geography of the Oceans • Of the 510 million square km of Earth’s surface 360 million square km is covered in water • The world ocean can be divided into four main ocean basins: • Pacific Ocean – largest and has the greatest depth • Atlantic Ocean – half the size of the Pacific and not quite as deep • Indian Ocean – slightly smaller than the Atlantic and is mainly in the southern hemisphere • Artic Ocean – 7% of the size of the Pacific

  6. What percentage of Earth’s surface is covered by water? • 45 percent • 51 percent • 71 percent • 85 percent

  7. Oceanography is the • science that draws on the methods and knowledge of geology, chemistry, physics and biology to study all aspects of the world ocean. • study of all the living organisms in the oceans. • study of ocean water chemistry. • study of the ocean floor and its topography.

  8. Which of the world’s oceans is the largest and deepest? • Arctic Ocean • Atlantic Ocean • Indian Ocean • Pacific Ocean

  9. The Vast World Ocean • Mapping the Ocean Floor • The topography of the ocean floor is as diverse as that of the continents. • Bathymetry – is the measurement of ocean depths and the charting of the shape or topography of the ocean floor. (bathos = depth, metry = measurement) • Challenger expedition – Dec. 1872-May 1876 • First understanding of the ocean floors topography • 127,500 km trip (every ocean except Artic)

  10. The Vast World Ocean • Today’s technology – particularly sonar, satellites, and submersibles – allows scientists to study the ocean floor in a more efficient and precise manner than ever before.

  11. The Vast World Ocean

  12. The Vast World Ocean • Sonar – an acronym for sound navigation and ranging. It is also referred to as echo sounding. • Developed in the 1920’s. • Sonar works by transmitting sound waves toward the ocean bottom and timing how long it takes for the echo to come back. • Used to map the ocean floor • “Mowing the lawn” – method of sonar where a multibeam sonar is used in a back and forth motion to map the ocean floor

  13. The Vast World Ocean

  14. The Vast World Ocean • Satellites • Satellites are able to measure small differences by bouncing microwaves off the ocean surface. • Using this new technology, scientists have discovered that the ocean surface is not perfectly flat. • Differences in the height of the ocean surface are caused by ocean-floor features.

  15. The Vast World Ocean

  16. Bathymetry is • the measurement of ocean currents, tides and waves. • the measurement of ocean depths and the charting of the shape or topography of the ocean floor. • the study of the various sediments on the ocean floor. • the study of seismic activity on the ocean floor.

  17. What does sonar equipment measure? • The density of the ocean’s water • The depth of the ocean floor • The sound produced by bottom-dwelling ocean creatures • The shape of the ocean surface

  18. Scientists use satellites to measure the • Ocean floor depth. • Size of underwater features. • Sea-surface height. • Ocean’s salinity.

  19. The Vast World Ocean • Submersibles – small underwater crafts used for deep-sea research. • First submersible used in 1934 by William Beebe • Dove 923 meters deep off of Bermuda • Steel sphere that was tethered to the ship • 1960 – Jacques Piccard descended 10,912 meters into the Mariana Trench • Untethered submersible named Trieste • Manned submersibles • Alvin – can reach 4000 meters • Sea Cliff II – can reach 6000 meters • Today, many submersibles are unmanned and operated remotely by computers. These remotely operated vehicles (ROVs) can remain underwater for long periods.

  20. Submersibles

  21. Which of the following is NOT an example of a submersible? • Alvin • Trieste • Sea Cliff II • Red October

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