2 The Ocean Floor What does the bottom of the ocean look like? If the water of the ocean were drained, what would you see?How much of the Earth is covered with water?Why is Earth called the “Blue Planet”?
3 The Blue Planet 70% of Earth’s surface covered by ocean. Fig 1 Pg 394 Makes no sense without caption in bookFig 1 Pg 394
4 The Blue PlanetThe world can be divided into four main ocean basins—the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, and the Arctic Ocean.The Pacific Ocean is the largest and has the greatest depth.
5 The Vast World OceanBathymetry is the measurement of ocean depths and charting topography of ocean floor36,000 ft deepMarianas trench
6 The ChallengerIn 1872 HMS Challenger expedition made the first study of Earth’s oceans65,000 mile trip took the ship and its crew of scientists to every ocean except the ArcticHow did they measure the depths of the oceans?used line and sinker
8 The Topography of the Ocean You could see mountains on bottomof ocean if Earth’s oceans were drainedMakes no sense without caption in book
9 The Topography of the Ocean A Continental slopeB SeamountC Continental RiseD Mid Ocean RidgeE Abyssal PlainF Continental ShelfG Ocean Trench
10 Measuring Topography on the Ocean Floor Three types of technology allow scientists to study the ocean floor1. sonar2. satellites3. submersibles
11 Measuring Topography on the Ocean Floor SonarInvented in the 1906 by Lewis NixonSonar is an acronym for Sound Ocean Navigation and RangingAlso referred to as echo soundingSonar works by transmitting sound waves toward the ocean bottom
12 Sonar MethodsMakes no sense without caption in book
13 Measuring Topography on the Ocean Floor SatellitesSatellites are able to measure small differences by bouncing microwaves off the ocean surfaceCan measure variations in sea-surface height as small as 3 to 6 centimeters (1 to 2 inches)Differences in the height of the ocean surface are caused by ocean-floor features
14 Satellite MethodsMakes no sense without caption in book
15 Measuring Topography on the Ocean Floor SubmersiblesSubmersibles are small underwater crafts used for deep-sea researchToday, many submersibles are unmanned and operated remotely by computers. These remotely operated vehicles (ROVs) can remain underwater for long periods
16 SubmersiblesFirst submersible was used in 1934 by William Beebe
17 Submersibles Submersibles can: Record video and photos of previously unknown creatures that live in the abyssCollect water samples and sediment samples for analysis