Ewing, William Maurice

Ewing, William Maurice,

1906–74, American oceanographer and geologist, b. Lackney, Tex., grad. Rice Institute, now Rice Univ. (B.S., 1926; M.A., 1927; Ph.D., 1931). He taught physics and geology at the Univ. of Pittsburgh and Lehigh Univ. and was a research associate at Woods Hole Oceanographic Institution in Massachusetts. In 1935, he took the first seismic measurements in open seas (Atlantic Basin at the Mid-Atlantic Ridge and in the Mediterranean and Norwegian Seas) and developed a seismometer that has become a standard. He proposed that earthquakesearthquake,
trembling or shaking movement of the earth's surface. Most earthquakes are minor tremors. Larger earthquakes usually begin with slight tremors but rapidly take the form of one or more violent shocks, and end in vibrations of gradually diminishing force called
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 are associated with central oceanic rifts and suggested that seafloor spreadingseafloor spreading,
theory of lithospheric evolution that holds that the ocean floors are spreading outward from vast underwater ridges. First proposed in the early 1960s by the American geologist Harry H.
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 may be worldwide and episodic in nature. In 1939, he took the first deep-sea photos. In 1944 he joined the faculty of Columbia Univ. and in 1949 founded and became the first director of Columbia's Lamont Geological Observatory (now Lamont-Doherty Geological Observatory) at Palisades, N.Y. Lamont-Doherty now holds one of the world's largest collection of deep-sea cores because of Ewing's many oceanic explorations. In 1960, Ewing became the first recipient of the Vetlesen Prize, an award given by the Vetlesen Foundation to honor leaders in the earth sciences.