William E. Bonini

William Emory Bonini (August 23, 1926 – December 13, 2016) was an American geologist and geophysicist. He was Professor of Geological Engineering at Princeton University and known for his global gravity and magnetic surveys that advanced the understanding of Earth's shape and crustal structure. From 1970 to 1996, he held the George J. Magee Professorship of Geoscience and Geological Engineering, after which he became emeritus.

Early life and education Bonini was born in Washington, D.C., in 1926. A fourth generation Washingtonian, he graduated from Western High School. He began his undergraduate studies at Princeton University in 1944 and was drafted into the United States Navy during World War II, where he trained in radar operations. He returned to Princeton to complete his B.S. in engineering in 1948 and M.S.E. in 1949. He earned his Ph.D. in geology and geophysics from the University of Wisconsin–Madison in 1957, Bonini was the first member of his family to earn a college degree.

Career Bonini joined the Princeton faculty in 1953, ultimately holding joint appointments in the Department of Geological and Geophysical Sciences and the Department of Civil Engineering and Operations Research. He taught courses in geophysics, field geology, and geological engineering for over four decades.

He served as chair of Princeton's Geological Engineering program from 1973 until his retirement. In the 1980s, he served terms as President of the National Association of Geoscience Teachers (NAGT), and as Chairman of the Geophysics Division of the Geological Society of America (GSA). A longtime board member of the YBRA, he served two terms as President (1958–1959; 1971–1973) and was the Director of the Princeton-YBRA Field Course program for over 30 years starting in 1959.

Geophysics research During the Cold War, Bonini collaborated with geophysicist George P. Woollard on U.S. Navy- and Office of Naval Research-funded geophysical surveys that supported strategic military objectives such as submarine navigation, missile guidance, and global geodetic refinement. A key focus of this work was the global standardization of gravity measurements. Bonini's contributions were acknowledged in the U.S. Air Force–funded Assembly of Gravity Data report (1959), which credited Woollard and colleagues with establishing a coherent World Gravimetric System.

Over the course of six global expeditions, Bonini conducted more than 400 gravity measurements across over 85 countries, from Alaska to Antarctica, using a Worden gravimeter sensitive enough to detect variations as small as one 100-millionth of Earth's gravitational pull. These measurements, conducted in part during U.S. Navy–sponsored missions, were instrumental in identifying regional gravity anomalies that interfered with vertical reference systems—especially in the Pacific—and in refining global navigation and missile guidance systems. and the Strait of Gibraltar. He also made contributions to the interpretation of complex structures in far-flung locations including the Northern Rockies, Nicaragua, Alaska, and Maine.

Personal life Bonini met Rose Rozich in 1952 while both were graduate students at the University of Wisconsin–Madison. They married on December 4, 1954, in Washington, D.C., and settled in Princeton, New Jersey, where they raised four children: John, Nancy, James, and Jennifer.

Bonini died on December 13, 2016, at the age of 90.

Honors and awards Bonini was awarded Princeton's President's Award for Distinguished Teaching in 1992. In 2010, he was awarded the Princeton University Award for Excellence in Alumni Education. From 2002 to 2019 the Princeton Department of Geosciences routinely presented a teaching award in Bonini's name.

In 2019, the Yellowstone Bighorn Research Association (YBRA) dedicated the Bonini Cabin in memory of William E. & Rose R. Bonini.

Selected publications Bonini authored and co-authored numerous scientific reports and peer-reviewed papers, including:

Moss, J.H. & Bonini, W.E. (1961). "Seismic Evidence Supporting a New Interpretation of the Cody Terrace Near Cody, Wyoming." GSA Bulletin, 72(4): 547–555. https://doi.org/10.1130/0016-7606(1961)72%5B547:SESANI%5D2.0.CO;2 Behrendt, J.C., Tibbetts, B.L., Bonini, W.E., Lavin, P.M., Love, J.D. & Reed, J.C. (1968). A geophysical study in Grand Teton National Park and vicinity, Teton County, Wyoming. U.S. Geological Survey Professional Paper 516-E. Bonini, W.E., Loomis, T.P. & Robertson, J.D. (1973). "Gravity anomalies, ultramafic intrusions, and tectonics of region around Strait of Gibraltar." Journal of Geophysical Research, 78(8): 1372–1382. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JB078i008p01372 Kellogg, J.N. & Bonini, W.E. (1982). "Subduction of the Caribbean Plate and basement uplifts in the overriding South American Plate." Tectonics, 1(3): 251–276. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/TC001i003p00251 Bonini, W.E., Hargraves, R.B. & Shagam, R. (1984). The Caribbean–South American Plate Boundary and Regional Tectonics. Geological Society of America Memoir 162, 421 pp. He also co-authored a physical geology textbook: Judson, S., Bonini, W.E., Rossbacher, L.A., Rhodes, D.D. & Kauffman, M.E. (1995). Physical Geology: The Lab Book (9th ed.). Pearson College Division, 260 pp.