Chapter 2

A grand tour

Story

From 1965 – 1967, McKenzie spent extended periods away from Madingley RiseMadingley RiseMadingley Rise, a generous late Victorian house in north Cambridge, played a central role in the development of geophysics at the University of Cambridge. It was built in 1891 for a professor of astronomy, Hugh Frank Newall, who introduced geodesy teaching at Cambridge. In 1955, it became home to the Department of Geodesy and Geophysics; Newall’s study became the Head of Department’s office. The pleasant surroundings, away from the centre of Cambridge, fostered a lively and productive community at this, the smallest of the five major world geophysical laboratories of the 1960s. In 1980, Madingley Rise became the Bullard Laboratory, and part of the newly-formed Department of Earth Sciences. at three centres of geophysics research: 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. , 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 from1957-65, was an innovator in quantitative research, and put an emphasis on computing in earthquake seismology. and LamontLamontLamont Geological Observatory (now Lamont-Doherty Earth Observatory) was established by Columbia University, New York in 1949 following a gift of land by the Lamont family. Maurice Ewing was its first director and his dedication to exploration and discovery established it as a world leader in geophysics. Ewing demanded comprehensive data collection on Lamont research voyages, building a vast store of data: the Vema alone covered more than a million miles in her working life at Lamont. Despite this, Ewing and his colleague Walter Bucher did not accept the mobilist worldview of plate tectonics. . The pattern of visiting research centres stood McKenzie in good stead; as the ideas that became plate tectonics developed, he was in touch with key people. “I knew Harry HessHarry HessHarry Hess (1906-1969) began his career at Princeton in the 1930s, undertaking submarine gravity experiments with Vening Meinesz. After war service and promotion to an Admiral of the US Navy, he returned to Princeton and his interests in marine geology. His proposal of seafloor spreading and the conveyor belt carrying new ocean crust away from the mid-ocean ridges was influential. He had also worked on the gravity anomalies that became associated with subduction zones, encouraging him to consider mantle convection as a part of plate tectonics. well, Teddy BullardTeddy BullardMcKenzie’s PhD supervisor, Edward Crisp Bullard (1907 – 1980), was a noted experimental physicist who devised innovative equipment and developed a dynamo theory to model the origin of the Earth’s magnetic field. He was a student of Ernest Rutherford and a pioneer of marine geophysics in the UK. He was head of the Department of Geodesy and Geophysics at Cambridge through the 1960s, noted as a good leader who supported his staff, always managing to find a little money to get a student to a significant conference or to kick-start a new project. was my supervisor, Tuzo WilsonTuzo WilsonJohn Tuzo Wilson (1908-1993) worked at Princeton and was the first to suggest that island chains such as Hawaii arose as plates moved across a hot spot in the mantle below. In the early 1960s, maps of the magnetic anomalies on the ocean floor showed symmetrical patterns at mid ocean ridges, cut by discontinuities. With simple paper models, starting from Vine and Matthews’ work, Wilson suggested that transform faults were not later faults affecting ridges, but rather essential parts of the ridge system. Lynn Sykes at Lamont showed that earthquake motions along the faults matched Wilson’s model, and that transform faults away from the ridges were inactive. I knew very well,” comments McKenzie. “I never got to know Maurice EwingMaurice EwingMaurice Ewing (1906-1974) graduated from Rice Institute (now University) in Texas and took a physics PhD there. He started to experiment with seismic surveying on land after his experiences as a summer worker for an oil prospecting company. From 1930 at Lehigh University he experimented with magnetic and seismic signals, and in 1937 he started working at sea on the Atlantis, developing methods to image beneath the ocean floor. He tried to interest oil companies in his ideas, to no avail. He went to Columbia in 1946 and from 1949 established the Lamont Geological Observatory. Despite Ewing driving the collection of so much of the data that led to the plate tectonics revolution, he himself remained unconvinced. , even though I was at LamontLamontLamont Geological Observatory (now Lamont-Doherty Earth Observatory) was established by Columbia University, New York in 1949 following a gift of land by the Lamont family. Maurice Ewing was its first director and his dedication to exploration and discovery established it as a world leader in geophysics. Ewing demanded comprehensive data collection on Lamont research voyages, building a vast store of data: the Vema alone covered more than a million miles in her working life at Lamont. Despite this, Ewing and his colleague Walter Bucher did not accept the mobilist worldview of plate tectonics. for a period. It was I suspect because Maurice was so opposed to the whole enterprise that he really didn’t want to talk to anyone who was making their reputation by doing something completely different from him.”

ARCHIVE REFERENCE: LDGSL/1107/C/2/2
Colour, group photograph of the members of the Seismological Laboratory, California Institute of Technology [Caltech], Pasadena, California, USA, taken in Spring 1967. McKenzie is in the back row, third from left. On McKenzie’s left is “Clarence Allan, who was at that time head of the Seismo Lab at Caltech, on his left is Don Anderson, who I think had just stopped being head. In the photo the old man second from the right in the back row is Charles Richter, of the Richter Magnitude fame”. [Information from McKenzie, July 2014].