The Deep-Sea Drilling Project (DSDP) was a scientific program for drilling cores of sediment and basaltic crust beneath the deep oceans and recovering them for study. The drilling began in 1968, using the ship Glomar Challenger, and ended in 1983. The DSDP was funded primarily by the National Science Foundation and was managed for a consortium of oceanographic laboratories by the Scripps Institution of Oceanography in La Jolla, Calif. Starting in the mid-1970s, countries such as France, Britain, West Germany, Japan, and the USSR also participated in and helped fund the DSDP, under the title of International Phase of Ocean Drilling (IPOD), but the association with the USSR was dissolved after its invasion of Afghanistan.

The DSDP, which was succeeded in 1984 by the Ocean Drilling Program, was itself a successor to the unsuccessful Mohole Project in which scientists attempted to drill an extremely deep hole reaching to the Earth's mantle. (Such attempts to reach the mantle are now being made on dry land; see drilling.) One major accomplishment of the DSDP was to demonstrate the existence of seafloor spreading and to prove that plate tectonics is the correct model of crustal geodynamics. Cores taken by the DSDP from the Pacific and Indian Oceans have been stored at the Scripps Institution; those from the Atlantic Ocean have been housed in the Lamont-Doherty Earth Observatory of Columbia University. The cores remain available at those institutions for study by any qualified scientist.

Robert S. Dietz

Bibliography: Hsu, K. J., The Challenger at Sea: A Ship that Revolutionized Earth Science (1992).