“I essentially follow my nose – I do what’s interesting. I have in my head a set of things in various categories. Things that are straightforwardly wrong. Things that I understand and I’m convinced the understanding is all right. Then there are things which I don’t understand but which are so complicated that I don’t think I’m ever going to understand. In tectonics, that’s essentially the tectonics of South East Asia, which is a real mess. And then there are things which I really do believe, which I absolutely don’t understand. At any time, there’s rather few of those but I’m very conscious always of what they are. What’s really important is whether I believe the observations on which they’re based. If I believe the observations and don’t understand the result, then that really is something which I have in my head as something which I want to work on.”

“I’ve lived through a period in which the technology of doing things on the Earth has changed absolutely radically. When I started, we didn’t know where the ships were to within a few km; you can now measure the motions between continents to an accuracy of less than millimetre. That technology, which is quite wonderful, has changed completely. And I’m very aware of what you can do with new technology. I don’t want to do it myself, because generally the new technologies involve skills which I don’t have, but on the other hand I bring to them things which in general the people who are actually doing the technology don’t have. Provided you’re reasonably generous there is a real win-win for both of you. This is particularly true at the moment with seismology.”

McKenzie has developed new interests throughout his career; one driver for this has been to avoid areas of interest to colleagues. “I made a rule that if one of my graduate students got hired by the department and wanted to go on with what they’d done as a research student, then I should give up that subject completely,” he says. “So once James JacksonJames JacksonJames Jackson (1954-present) of the University of Cambridge works on active deformation of the continents, focusing on earthquake source seismology alongside geomorphology, space geodesy and remote sensing. He is interested in quantifying not only the deformation from individual fault ruptures but also in how individual earthquakes combine to produce the landscape of active tectonic regions. was on the staff, I really stopped doing continental tectonics except with him a little. I’m always quite happy to do this because I learn, I get into a new subject, particularly as the technology moves on.”

McKenzie is noted for extensive collaborative work with people in distinct fields. “This has worked extremely well,” he recollects. “I was given a prize, by the American Geophysical Union, for ‘unselfish cooperation in research’. I said in my acceptance speech that I had never cooperated unselfishly with anyone – cooperation works only if there’s something in it for both of you. I had had 120 co-authors; nearly all of them I’m on good terms with because there was something in it for all of us. But I didn’t intend to refuse the award because I had not been unselfish…”