Sir Edward "Teddy" Crisp Bullard FRS (21 September 1907 - 3 April 1980) was a geophysicist who is considered, along with Maurice Ewing, to have founded the discipline of marine geophysics. He developed the theory of the geodynamo, pioneered the use of seismology to study the sea floor, measured geothermal heat flow through the ocean crust, and was one of the first to find new evidence for the theory of continental drift.