Leon Knopoff (July 1, 1925-January 20, 2011) was a geophysicist and musicologist.[1] He received his education at Caltech, graduating in 1949 with a PhD in physics, and after holding several academic positions, moved to UCLA. He has done fundamental work in the field of theoretical seismology, for which he was honoured in 1979 by the award of the Gold Medal of the Royal Astronomical Society.[2] He is also a member of the American Academy of Arts and Sciences.

Life and Work

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In Draft while awaiting approval from author Stuart Wolpert to use this text from UCLA Today[3]

Knopoff was an internationally renowned scientist who served on UCLA's faculty for 60 years and made significant research contributions in physics, seismology, and music. The author of more than 360 scholarly publications and editor or co-editor of five books, he received many honors, including election as a member or fellow to the National Academy of Sciences (1963), the American Academy of Arts and Sciences (1965), the American Association for the Advancement of Science (1964), the Guggenheim Foundation (1976), and the American Philosophical Society (1992). He also earned the Medal of the Seismological Society of America (1990) and the gold medal of the Royal Astronomical Society (U.K., 1979). He was awarded an honorary doctorate from the University of Strasbourg (2004) and was named the first honorary professor of the Institute of Geophysics of the China Earthquake Administration (2004). He served on the editorial board of the journal Science (1985-1990) and on the California Governor's Earthquake Council (1972–74). He received four outstanding teaching awards from UCLA's physics department. At UCLA, he supervised 38 Ph.D. students, as well as 39 postdoctoral scholars from 17 countries.

"Leon Knopoff's career was exemplary, replete with numerous examples of outstanding contributions to fundamental geophysics," said his colleague, Paul M. Davis, a UCLA professor of geophysics. "His trademark approach has been to apply developments in mathematical physics and condensed matter physics to seismology, contributing both to physics and geophysics. Leon was extremely creative, unusually prolific, and elegant in his choice of research topics. His service to his university and profession has also been extraordinary. His selfless cooperation has been truly global. As a teacher, he reduced complexity to its simplest terms with an infectious enthusiasm and a caring empathy for his students. His graduate students, recognized for their rigorous training in fundamentals, have been sought after and have gone on to successful careers in academia and industry." "Extreme rigor and thorough consideration of alternate interpretations were hallmarks of Leon's research, and he was known for his exceptional clarity in teaching," said his UCLA colleague, David D. Jackson, a professor of geophysics. "He was also a wonderful mentor."

Knopoff earned his Ph.D. in physics and mathematics from the California Institute of Technology in 1949 and came to UCLA the following year as a research associate in geophysics. He was promoted to associate professor at UCLA's Institute of Geophysics in 1957 and three years later was appointed to full professor at the institute and in the physics department. He served as director of the UCLA Institute of Geophysics and Planetary Physics (IGPP) from 1972 to 1986 and became a research musicologist in 1960 at the newly formed UCLA Institute of Ethnomusicology.

Knopoff's research focused on the physics and statistics of earthquakes, earthquake prediction, the interior structure of the Earth, plate tectonics, pattern recognition, non-linear earthquake dynamics, and several other areas of solid Earth geophysics. His wide-ranging research interests also included musical perception and the dating of ancient pottery by thermoluminescence. Best known for his theoretical breakthroughs, he also made pioneering measurements of seismic wave velocities and tidal gravity variations at the South Pole. One of the milestones in the evolution of seismology is the representation theorem by Knopoff and Robert Burridge in 1964. It is recognized as the first principle in modern seismology. In addition, a widely cited model by Knopoff and Burridge in 1964 attracted widespread attention in statistical physics and seismology and is regarded as one of the most important models in condensed matter physics.

Among the discoveries from his systematic research on the statistics of earthquakes was that most small earthquakes are not genuine predictors of subsequent instability on a major fault; however, they do play the role of a stress gauge. He and his colleagues also found that large earthquakes cluster in space and time. Knopoff worked on the development of a comprehensive theory of earthquakes, including sudden increases in precursory seismicity, aftershocks, and foreshocks.

Knopoff visited China in the 1970s, returning there several times to lecture and meet with students and scientists.

In September 2000, UCLA's IGPP honored Knopoff's 75th birthday and his 50th anniversary at UCLA with a symposium titled "The Earth: Earthquakes and Seismic Waves." The majority of his former Ph.D. students attended, along with many of his colleagues and former postdoctoral scholars, some of whom came from as far as Australia, China, Germany, and Russia.

References

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  1. ^ Gangi, A. F.; Fredricks, R. W.; Hook, J. F. (2000). "A volume in honour of Leon Knopoff's 75th birthday". Geophys. J. Int. 143 (2): i–ii. doi:10.1046/j.1365-246X.2000.01278.x. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: date and year (link)
  2. ^ Seaton, M.J. (March 1981). "Gold Medal Awarded to Knopoff, Leon". QJRAS. 22: 1. Bibcode:1981QJRAS..22....1S.{{cite journal}}: CS1 maint: date and year (link)
  3. ^ Wolpert, S. (January 2011). "Obituary: Leon Knopoff, 85, internationally distinguished UCLA scientist". UCLA Today.{{cite journal}}: CS1 maint: date and year (link)


Category:1925 births Category:American geophysicists Category:American seismologists Category:Recipients of the Gold Medal of the Royal Astronomical Society