Keith Runcorn was born in Southport, Lancashire. He worked on radar research during the war and pioneered the investigation of the history of the earth's magnetic field. He was an early supporter of the once-derided but now triumphant theory of continental drift.
Runcorn was head of the physics department at Newcastle University from 1956 to 1988, where he kept up a flow of controversial theories; later, he became professor of physical science at the University of Alaska. Runcorn was one of science's international statesmen and took part in projects throughout the world, being consulted by NASA in connection with the Apollo landings. His expertise in planetary physics led to his Newcastle department becoming a NATO advanced study institution. He was also associated with the controversial Biosphere II project in Arizona, in which a group of people lived in an enormous glass dome for two years before being released in 1993.
A keen club rugby player, Runcorn was a good-natured and kindly man, with a wide appreciation of the arts. Most visitors to Newcastle were taken to Durham Cathedral and the Roman Wall. It came as a great shock when he was found murdered in a hotel in San Diego in 1995, where he was to attend the American Geophysical Union in San Fransisco.