born May 12, 1906, Lockney, Texas, U.S.
died May 4, 1974, Galveston, Texas
U.S. geophysicist.
He taught many years at Columbia University (194474) and also directed the Lamont-Doherty Geological Observatory (194974). 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.