John Sclater: 1940-2024

John Sclater, a geophysicist at UC San Diego’s Scripps Institution of Oceanography and a member of the first wave of scientists who contributed to the theory of plate tectonics, died Oct. 20 at his San Diego home. He was 84.

Born in Edinburgh, Scotland on June 17, 1940, Sclater attended Edinburgh University and received his doctorate from Cambridge University in 1966. He joined Scripps Oceanography as a researcher the following year, taking part in the 1968 Circe Expedition and the 1970 Seven-Tow Expedition, both of which contributed to the new field of plate tectonics – which describes the movement of continents on Earth – through investigations of seafloor spreading and crustal movement in the Indian Ocean and south Pacific Ocean.

“John was renowned for his work on heat flow and subsidence of the seafloor, which was instrumental for tying plate tectonics to mantle convection and planetary heat flow,” said Dave Bercovici, Frederick William Beinecke Professor of Earth & Planetary Sciences at Yale University. “He also did seminal work on paleoceanography and continental crust stretching, all by synthesizing seismology, magnetism and heat flow measurements.”

Sclater left Scripps Oceanography in 1972 for the Massachusetts Institute of Technology, where he became a professor in 1977. He moved to the University of Texas at Austin to serve as a distinguished professor of geophysics and associate director before returning to Scripps as a professor of geophysics in 1990. He remained at Scripps until retiring in 2017. 

Colleagues remembered Sclater not just as a leading scientist but as an important mentor and friend.

“John Sclater was a towering giant in the field of marine geophysics, and one of my personal heroes,” said Marcia McNutt, president of the National Academy of Sciences and a Scripps alumna. “His contributions to the plate tectonic revolution were original, impactful, and enduring. He was a friend and mentor at a time when many men of his stature couldn’t be bothered to offer a leg up to young women seeking to make their mark in a male-dominated field. His enthusiasm for research was infectious and his creativity inspiring. My one regret is not having had the opportunity to thank him personally for all that he meant to me and my career."

Science historian Naomi Oreskes authored a 2003 book about the history of the origin of plate tectonics theory titled “Plate Tectonics: An Insider’s History of the Modern Theory of the Earth,” which included a chapter on heat flow under the seafloor written by Sclater. Oreskes said she was struck during her research by Sclater’s championing of Tanya Atwater, the first female professor at Scripps Oceanography.

“John felt strongly that Tanya, as a woman, had been mistreated, and never got the full credit she deserved for her path-breaking work,” Oreskes said. “Many scientists make a point of trying to impress the historian with the importance of their own work. It is the rarer scientist who takes the opportunity to highlight someone else’s work, and particularly to try to make sure that others get the historical credit they deserve.” 

Sclater was elected a Fellow of the American Geophysical Union in 1981, a Fellow of the Royal Society in 1982, and a Guggenheim Fellow in 1998. He was elected to the National Academy of Sciences in 1989. He co-authored more than 180 research studies and his 1977 study on heat flow has been cited more than 3,000 times.

Sclater is survived by wife Naila Gloria Sclater, daughter Daniela Elyza Sclater, sons Iain Sclater and Stuart Sclater of San Diego from his first marriage, stepsons Fabio De Faria and Felipe Da Costa, and sisters Elizabeth Sclater and Marjory Lally.

The celebration of life will be held January 21, 2025 at 2:00 p.m. at the Martin Johnson House on the Scripps Institution of Oceanography campus. 

TRIBUTES: 

“I first met John in Cape Town in 1973 when he came into port on the Atlantis II after a cruise to the Bouvet Triple Junction. I had been surveying further east on the SW Indian Ridge as part of my thesis work at the Bernard Price Institute, University of Witwatersrand. John saw the potential of a shared data project between our universities, and eventually obtained funding for me to join him at MIT to work on a combined mapping project.  This eventually led to my being able to get a green card and emigrate to the USA, so I owe all of this to John and his go-getter attitude for which I am eternally grateful.  The time in John's group at MIT was incredible, he maintained an insatiable thirst for knowledge and science, every day was a sensory overload.” – Ian Norton, University of Texas (retired)