Edward Bullard

Sir Edward Crisp Bullard was an English geophysicist, born in 1907 in Norwich and died in 1980 in La Jolla, California. He is regarded, along with Maurice Ewing, as a founder of marine geophysics, and in 1954 he announced that ocean floor heat flow measurements showed no significant difference from continental crust, an unexpected result that helped drive research toward plate tectonics. He proposed that Earth's magnetic field is generated by a dynamo process in the convecting liquid iron of the outer core, and he later led the Cambridge geodesy and geophysics department at the center of the 1960s plate tectonic revolution.