Chapter 2

The beginning of plate tectonics

“I was new to writing research papers and I didn’t make enough of this, I didn’t explain enough.”


After returning to the UK, McKenzie wrote up his PhD thesis on “The shape of the Earth”. In the three weeks between submitting the thesis and the examination, he set down the ideas that had come to him at ScrippsScrippsScripps Institution of Oceanography, San Diego, California was established to support marine biological research, but from 1908 onwards pioneered geophysical research in the oceans. Teddy Bullard was a frequent visitor and undertook early ocean floor heat flow measurements with Roger Revelle. In 1962 the University of California established the new Institute of Geophysics and Planetary Physics alongside Scripps in La Jolla. and after the 1966 New York meeting: that ridges could not be the result of mantle convection, but rather that the small heat flow anomalies along them were passive effects of the separation at the ridge. He did the coding later, at CaltechCaltechThe California Institute of Technology originated in 1891, but took its modern form (and name) in 1921; seismology was a concern in southern California and in 1937 the Seismological Laboratory moved to Caltech. Charles F Richter and Beno Gutenberg established their measurement scale for earthquakes there and by the 1960s the Seismo Lab was a focus for earthquake research. Frank Press, who was Director from 1957-65, was an innovator in quantitative research, and put an emphasis on computing in earthquake seismology., where he ran the models and produced the figures for the 1968 paper. “I did all the maths while I was waiting for my thesis to be examined,” says McKenzie. “But I was new to writing research papers and I didn’t make enough of this, I didn’t explain enough.”

Page of calculations for the strength of the lithosphere, relating to the paper, McKenzie, “Some remarks on heat flow and gravity anomalies”, Journal of Geophysical Research, 72:6261-6273 (1967).