The Seismological Society of America (SSA) will present its highest honor, the 2021 Harry Fielding Reid Medal, to William Ellsworth, professor of geophysics at Stanford University.
Ellsworth, who will receive the Reid Medal at the 2022 SSA Annual Meeting, is recognized for his critical contributions to earthquake location, earthquake nucleation, earthquake recurrence and induced seismicity research.
With Felix Waldhauser, Ellsworth developed the double-difference (DD) earthquake location method, which has had a tremendous influence on the field of seismology since the publication of the seminal study in the Bulletin of the Seismological Society of America in 2000. The DD method has been used in thousands of investigations to precisely locate earthquakes, revealing the intricacies of fault geometry deep below ground.
Among Ellsworth's other notable research is his work on earthquake foreshock sequences and possible earthquake nucleation phases, and more recently a body of work on the causes and consequences of induced seismicity. He is the co-director of the Stanford Center for Induced and Triggered Seismicity (SCITS).
His work on understanding the causes of and solutions to induced seismicity attests to his scientific creativity, productivity, and outstanding mentorship, according to Stanford geophysicist Mark Zoback, who nominated Ellsworth for the award.
"Needless to say, we are delighted that our students can learn seismology with theoretical rigor from someone with vast practical experience and a long and distinguished career as an academic and public servant," Zoback said in his nomination. "He has been extremely generous with students and colleagues and contributes with a level of energy and enthusiasm one would expect from someone just starting their career."
Ellsworth began his career at the U.S. Geological Survey in 1971. He was chief of the Branch of Seismology of the U.S. Geological Survey from 1982 to 1988 and chief scientist of the USGS Earthquake Hazards Team from 2002 to 2005. During his career at USGS and Stanford, Ellsworth has served on numerous review and advisory panels, including his current position as chair of the USGS's Earthquake Early Warning External Working Group.
Among his many honors, Ellsworth is a past president of the Seismological Society of America, a Fellow of the American Geophysical Union and recipient of the Distinguished Service Award of the Department of the Interior.
Ellsworth received his B.S. in physics and M.S. in geophysics from Stanford in 1971 and his Ph.D. in geophysics from Massachusetts Institute of Technology in 1978.
First awarded in 1975, the Medal recognizes outstanding contributions in seismology and earthquake engineering. Harry Fielding Reid, a pioneering American seismologist, proposed in 1911 the elastic-rebound theory, concerning the buildup and release of stress and strain around faults as a cause of earthquakes.