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.
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 waterThe world ocean can be divided into four main ocean basins:Pacific Ocean – largest and has the greatest depthAtlantic Ocean – half the size of the Pacific and not quite as deepIndian Ocean – slightly smaller than the Atlantic and is mainly in the southern hemisphereArtic Ocean – 7% of the size of the Pacific
6 What percentage of Earth’s surface is covered by water?
7 Oceanography is thescience 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 OceanAtlantic OceanIndian OceanPacific 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 May 1876First understanding of the ocean floors topography127,500 km trip (every ocean except Artic)
10 The Vast World OceanToday’s technology – particularly sonar, satellites, and submersibles – allows scientists to study the ocean floor in a more efficient and precise manner than ever before.
12 The Vast World OceanSonar – 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
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.
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 waterThe depth of the ocean floorThe sound produced by bottom-dwelling ocean creaturesThe 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 OceanSubmersibles – small underwater crafts used for deep-sea research.First submersible used in 1934 by William BeebeDove 923 meters deep off of BermudaSteel sphere that was tethered to the ship1960 – Jacques Piccard descended 10,912 meters into the Mariana TrenchUntethered submersible named TriesteManned submersiblesAlvin – can reach 4000 metersSea Cliff II – can reach 6000 metersToday, many submersibles are unmanned and operated remotely by computers. These remotely operated vehicles (ROVs) can remain underwater for long periods.