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. 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.

The Vast World Ocean

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

What percentage of Earth’s surface is covered by water?

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.

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

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)

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.

The Vast World Ocean

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

The Vast World Ocean

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.

The Vast World Ocean

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.

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

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

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.

Submersibles

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