Ewing, Maurice

Ewing, (William) Maurice

(born May 12, 1906, Lockney, Texas, U.S.—died May 4, 1974, Galveston, Texas) U.S. geophysicist. He taught many years at Columbia University (1944–74) and also directed the Lamont-Doherty Geological Observatory (1949–74). Studying the structure of the Earth's crust and mantle, he made seismic refraction measurements in the Atlantic basins, along the Mid-Atlantic Ridge, and in the Mediterranean and Norwegian seas. In 1935 he took the first seismic measurements in open seas. He was among those who proposed that earthquakes are associated with the central oceanic rifts that encircle the globe, suggesting that seafloor spreading may be worldwide and episodic in nature. In 1939 he took the first deep-sea photographs.

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Ewing, (William) Maurice (1906–74) oceanographer, seismologist; born in Lockney, Texas. He taught at Lehigh University (1930–43), then at Columbia University (1944–72), where he became founding director of its Lamont (now Lamont-Doherty) Geological Observatory in 1949. He left the observatory to join the Marine Biomedical Institute of the University of Texas (1972–74). A pioneer in oceanography, his gravity and seismographic surveys (1935–39) determined the vast thickness of continental margin sedimentary rocks, while his Atlantic explorations in the 1940s demonstrated the relative thinness of the earth's subocean crust. His later marine seismographic research (1956) indicated that the Mid-Atlantic Ridge is part of a continuous global submarine system, and that geological activity at its deep central rift supported the sea-floor spreading hypothesis of H. H. Hess. Ewing's controversial hypothesis of ice age periodicity, based on freezing and thawing of the Arctic Ocean, remains unproven.