Carnegie Institution for Science geochemist Erik Harold Hauri, whose work upended our understanding of the Moon’s formation and the importance of water in Earth’s interior, died on 5 September 2018 in North Potomac, Maryland, following a battle with cancer. He was 52. Born in Waukegan, Illinois, on 25 April 1966, Erik grew up in Richmond, a small town near the Wisconsin border. His mother was a homemaker and his father an auto mechanic and avid fisherman, who took his son on frequent trips that stimulated a lifelong passion for the outdoors.
Erik was the first in his family to attend college and set that standard very high by obtaining an advanced degree and becoming a world-renowned Earth scientist. His academic journey began early with a first move to the University of Miami, Coral Gables, Florida, to obtain a B.S. with honors in geology and marine science in 1988. After that, he studied at the MIT/Woods Hole Oceanographic Institution Joint Program in Earth Science, obtaining his Ph.D. in 1992 under the mentorship of Stan Hart and Nobu Shimizu, both alumni of Carnegie’s Department of Terrestrial Magnetism (DTM). His Ph.D. thesis was titled, “Geochemical and Fluid Dynamic Investigations into the Nature of Chemical Heterogeneity in the Earth’s Mantle.”
Although based in the Northeast U.S., Erik began what would be a lifelong connection to the far-flung field sites that were the source of the rocks he studied. In his citation of Erik for the Macelwane Medal of the American Geophysical Union, Stan Hart noted that Erik's first field excursion was a two to three week trip to Polynesia. Hart wrote: "But then, every Friday, I would get a telegram from [Erik in] a new southwest Pacific island saying, 'lots of interesting rocks, but can you wire some more money?'" After three months, Erik returned with literally tons of volcanic and mantle rocks that followed him to DTM and served as a source of important discoveries for years to come.
Erik was hired by then DTM Director Sean Solomon as a DTM Scientific Staff member in February of 1994. At DTM, Erik quickly established one of the best ion microprobe laboratories in the world. Working with colleague Jianhua Wang, Erik pushed the performance of the ion microprobe to new levels of sensitivity. This advance was essential for the analysis of the variety of volatile elements such as hydrogen and carbon, that are so essential both to the dynamics of Earth's interior and to life on its surface. Working with colleague Alberto Saal, Erik's push to improve the volatile element detection limits of the ion microprobe led to the ability to detect water in what were previously believed to be "bone dry" volcanic rocks from the Moon. This discovery drove new wide-ranging investigations of the process of the Moon’s formation and the consequences of water for the geochemical evolution of our neighbor in space. Erik's work on the Moon's water was highlighted as #47 in Discover Magazine's Best Science of 2013. The announcement of the discovery was covered by media worldwide, including the New York Times, MSNBC, The Boston Globe, the BBC, CBS, and Bloomberg News. Erik told National Public Radio in a 2011 interview, “If you take our measurements and use them to estimate the water content of the interior of the moon, you arrive at a volume of water that’s equivalent to the Mediterranean Sea. Now that’s a fair bit of water.”
This interest in volatile elements made Erik a natural fit to lead the Reservoirs and Fluxes community of the Deep Carbon Observatory (DCO), a global collaborative of more than 1000 scientists whose mission is to understand the quantities, movements, forms, and origins of carbon inside Earth. Erik not only investigated the fluxes of water into and out of Earth's interior along the planet's chain of island arc volcanoes, but also focused on its deeper circulation through the study of diamonds and the mineral inclusions they contain. Erik's early contributions led to him to winning early career awards from both the American Geophysical Union and the European Association of Geochemistry, two of the primary professional societies in his field. His continuing major contributions more recently led to his election as Fellow of both societies.
Besides his major contributions to science, Erik was very dedicated to his family, and with his wife Tracy (Spears) raised three children, Kevin, Matthew, and Michaela, seeing them through their home schooling and the large number of swim meets in which they participated. In his limited free time, Erik became a talented luthier, designing and building more than a dozen guitars and bass guitars, extending his garage-band role from college throughout his career.
Although his time on Earth was cut unfairly short, Erik Hauri made the most of his life and leaves behind a loving family and a record of major contributions to the understanding of the natural world around us. He was a distinguished gentleman of science that his many friends and colleagues around the world will sorely miss.
The HAD is grateful to Richard W. Carlson, Director, Department of Terrestrial Magnetism, Carnegie Institution for Science, for permission to include in this obituary portions of memorial essays posted at Carnegie’s web sites:
Photo: Steve Jacobsen, Northwestern University