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paleomagnetism

(Encyclopedia)paleomagnetism, study of the intensity and orientation of the earth's magnetic field as preserved in the magnetic orientation of certain minerals found in rocks formed throughout geologic time. Paleom...

Deep Sea Drilling Project

(Encyclopedia)Deep Sea Drilling Project, U.S. program designed to investigate the evolution of ocean basins by core drilling of ocean sediments and underlying oceanic crust. Funded by the National Science Foundatio...

Indian Ocean

(Encyclopedia)Indian Ocean, third largest ocean, c.28,350,000 sq mi (73,427,000 sq km), extending from S Asia to Antarctica and from E Africa to SE Australia; it is c.4,000 mi (6,400 km) wide at the equator. It con...

lava

(Encyclopedia)lava läˈvə [key], molten rock that erupts on the earth's surface, either on land or under the ocean, by a volcano or through a fissure. It solidifies into igneous rock that is also called lava. Bef...

coral reefs

(Encyclopedia)coral reefs, limestone formations produced by living organisms, found in shallow, tropical marine waters. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an...

continental drift

(Encyclopedia)CE5 Continental drift (arrows indicate the directions of motion of the landmasses) A. Proposed reconstruction of the supercontinent Pangaea indicating the major present landmasses B. Proposed recon...

echo sounder

(Encyclopedia)echo sounder, an older instrumentation system for indirectly determining ocean floor depth. Echo sounding is based on the principle that water is an excellent medium for the transmission of sound wave...

submersible

(Encyclopedia)submersible, small, mobile undersea research vessel capable of functioning in the ocean depths. Development of a great variety of submersibles during the later 1950s and 1960s came about as a result o...

Atlantic Ocean

(Encyclopedia)CE5 Atlantic Ocean [Lat.,=of Atlas], second largest ocean (c.31,800,000 sq mi/82,362,000 sq km; c.36,000,000 sq mi/93,240,000 sq km with marginal seas). The North Atlantic Ocean has some of the w...

windmill

(Encyclopedia)windmill, apparatus that harnesses wind power for a variety of uses, e.g., pumping water, grinding corn, driving small sawmills, and driving electrical generators. Windmills were probably not known in...