Columbia University New York, N.Y. 10027 Office of Public Information (212) 854-5573
A geophysicist who helped explain many of the basic physical processes that shape the earth now says that earth scientists increasingly must turn to a new field for answers: geochemistry.
Throughout his career Dan McKenzie, a Cambridge University professor, has applied the laws of physics to solve several fundamental problems in earth sciences--from the movement of earth's great crustal plates to the deformation of continents. But he says that scientists now need to combine explorations of geochemical and physical processes in the earth's upper layers to achieve a fuller understanding of the workings of the planet. Professor McKenzie will discuss new research approaches in the earth sciences in the annual Wenceslas S. Jardetzky Lecture in Geophysics Thursday, Nov. 16, at Columbia University's Lamont-Doherty Earth Observatory in Palisades, N.Y.
His lecture, titled "Thirty Years As a Geophysicist, or Why We Now All Have to Become Geochemists," begins at 4 P.M. in Room 203 of the Geoscience Building. It is free and open to the public.
"About 30 years ago, the earth sciences were taken over by physicists, who believed that they could use physical ideas and measurements to understand how the earth behaves," Professor McKenzie says. "They used echo sounders, gravimeters, magnetometers and seismographs and applied simple ideas to model the observations, the majority of which were made by scientists at Lamont, with outstanding success.
"But as commonly happens, application of the same methods to problems left unsolved by the first advance has not been nearly so productive," he says. "In my view what is needed is the new set of observations and theory that geochemistry can provide."
His lecture will illustrate several examples of his recent research that explore or invoke geochemical processes in the Pacific Ocean, on Iceland and within the earth's mantle and Venus.
Professor McKenzie was a leading figure in developing plate tectonic theory. He showed how the earth's rigid plates move over a sphere and how heat flow in the earth's upper layers determines the structure of mid-ocean ridges. His research on continental deformation and the creation of sedimentary basins provided the framework still used by industry for oil exploration. In later years, he pioneered research on convection within the mantle, and in the past decade, he has studied the generation of magma within the earth and Venus.
The Jardetzky lecture honors the late Wenceslas S. Jardetzky, a renowned researcher and educator whose scientific career in Europe was halted by World War II and revived after he emigrated to the United States. From 1949 until his death in 1962 he was a research associate at Lamont-Doherty. His broad scope of scientific interests included celestial mechanics, fluid dynamics, theoretical physics, seismology and polar migration. His mathematical theory on zonal rotation provided a mechanism for the migration of continents.
The Jardetzky lecture was established in 1992 by Dr. Jardetzky's son, Oleg, who is director of the Magnetic Resonance Laboratory and professor of pharmacology at Stanford University. In endowing the lectureship, Dr. Jardetzky said he hoped it would "help enrich the outstanding tradition of the Lamont-Doherty Earth Observatory, which provided a much cherished intellectual home to my father after he emigrated to this country."