This prestigious fellowship is named after Marie Tharp, the first scientist to map details of the ocean floor on a global scale.  She published the pivotal interpretation of mid-ocean ridges that was crucial to the eventual acceptance of the theories of plate tectonics and continental drift. Tharp based her work on data from sonar readings obtained by Maurice Ewing and his team.  Piecing together data from the late 1940s and early 1950s, she and colleague Bruce Heezen discovered a 40,000-mile underwater ridge girdling the globe and established the foundation for the conclusion that the sea floor spreads from central ridges and that the continents are in motion with respect to one another—a revolutionary geological theory at the time.  Years later, satellite images proved Tharp’s maps to be accurate.  Tharp came to Columbia in 1948 and then moved to the Lamont Geological Observatory (now the Lamont-Doherty Earth Observatory), where she began work on mapping the ocean floor. Her map of the ocean floor is still a foundation for research and education in the ocean sciences.