Geophysicist and university professor who, as research associate at
Woods Hole Oceanographic Institution (1940-1945), perfected under-water
communication techniques and pioneered the exploration of the ocean
floors by seismic waves. Director of Columbia University's Lamont
Doherty Geological Observatory (1949-1974), he discovered evidence
supporting the theory of continental drift. Inventor and designer of
the SOFAR ("Sound Fixing and Ranging") system, a sonic method for
rescuing men lost at sea, and also of a camera that could take
underwater pictures at a depth of more than three miles.