Bullard, Edward Crisp (1907–1980)

English geophysicist who, with US geologist Maurice Ewing, founded the discipline of marine geophysics. He pioneered the application of the seismic method to study the sea floor. He also studied continental drift before the theory became generally accepted. He was knighted 1953.

Bullard was born in Norwich and educated at Cambridge. During World War II he did military research, and he continued to advise the UK Ministry of Defence for several years after the war. He was professor of geophysics at the University of Toronto, Canada 1948–50; director of the National Physical Laboratory at Teddington, Middlesex 1950–57; and head of geodesy and geophysics at Cambridge 1957–74. He was also a professor at the University of California from 1963, and advised the US government on nuclear-waste disposal.

Bullard's earliest work was to devise a technique (involving timing the swings of an invariant pendulum) to measure minute gravitational variations in the East African Rift Valley. He then investigated the rate of efflux (outflow) of the Earth's interior heat through the land surface; later he devised apparatus for measuring the flow of heat through the deep sea floor.

While at Toronto University, Bullard developed his ‘dynamo’ theory of geomagnetism, according to which the Earth's magnetic field results from convective movements of molten material within the Earth's core.