Amos Nur

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Amos Nur
Amos Nur headshot.jpg
PhD university MIT


Amos Nur is widely considered one of the world’s top academic authorities on rock physics. He applies rock physics results to the understanding of tectonophysical processes in the Earth’s crust and lithosphere, a major thrust of which is the role of fluids in crustal processes and in energy resources. Nur pioneered the use of seismic velocity measurements to characterize the changing state of oil and gas reservoirs as the volume of fluid in the rock changed during pumping; the process has come to be known as “four-dimensional” seismic monitoring. He has published over 240 papers and guided dozens of doctoral and master’s candidates. Nur was on the Stanford faculty from 1970 until his retirement in 2008 and he remains affiliated with the school as professor emeritus. After his retirement, Nur joined Ingrain, a company he helped found in 2007, and where he now is Chief Technology Officer.

Biography Citation for the Maurice Ewing Medal 2011 [1]

Contributed by Gary Mavko

Selection of Amos Nur to receive the Maurice Ewing Medal is richly deserved and eminently fitting. Amos has been an extraordinary scientist and an inspiring teacher throughout his career, profoundly influencing the way many of us understand the Earth. In many circles, the term “rock physics” is synonymous with his name. Perhaps more than anyone else, through his visionary scientific innovation, tenacity, and keen eye for practical implications, Amos has brought rock physics from a scientific niche to a critical, integral part of modern geophysics.

Early years and education

Even as a young graduate student at MIT, Amos made discoveries that would have far-reaching impact. He was the first to experimentally observe and explain stress-induced anisotropy (shear-wave splitting) in rocks. His work on the elastic properties of fractured rock would form much of the experimental and theoretical basis for modern methods of seismic fracture detection and mapping. He was among the first to observe experimentally that seismic velocity is sensitive to effective pressure and fluid saturation, phenomena that have become the cornerstones of seismic detection and monitoring of hydrocarbon reservoirs.

Stanford University

Amos joined the Geophysics faculty at Stanford University in 1970. There, he founded the Stanford Rock Physics and Borehole Geophysics (SRB) Project, one of the earliest university-industry consortia in the country, and one that would become a model for fruitful collaboration between academia and the oil industry. Under his leadership, the SRB Project became a leading center for research and development in rock physics experiment, theory, and application. Since SRB’s beginnings, Amos and his nearly 100 PhD and master’s students have developed and established rock physics as a mature technology essential to exploration, reservoir characterization, and time-lapse monitoring. In fact, Amos was the first to propose the rock physics principles for 4D seismic monitoring of oil and gas production.

As a teacher and mentor, Amos has always emphasized individualism, creativity, and breadth. His students have become academic and industry leaders in rock physics, geomechanics, earthquake mechanics, crustal deformation and faulting, methane hydrates, environmental geophysics, and computational rock physics. To all these students, his unifying message has been to understand the physical mechanisms underlying natural phenomena in the presence of complex and sometimes contradictory observations. Amos always seems happiest when faced with a contradiction that forces him to rethink conventional wisdom. As a result, he has been no stranger to controversy, and in fact has welcomed it with intellect, humor, and grace, urging his students to do likewise.

Amos became a full professor at Stanford in 1979 and held the Wayne Loel Professorship in Earth Sciences from 1988 until his retirement. He served as Chair of the Geophysics Department, and as Director of Stanford’s university- wide Overseas Studies Program. Amos was awarded the American Geophysical Union’s Macelwane Award in 1974.

Fellow of the American Geophysical Union

He was elected a Fellow of American Geophysical Union in 1976, and a Fellow of the Geological Society of America in 1980. In 2001 he was elected to the National Academy of Engineering. He was awarded SEG Honorary Membership in 1996 and was an SEG Distinguished Lecturer in 1997. Always a visionary, Amos has made his mark outside of exploration geophysics, as well. In the 1970s, he proposed dilatancy-diffusion as a mechanism underlying anomalous VP/VS ratios observed before some earthquakes, spawning tremendous debate and scores of papers. His ideas on block rotation tectonics led to better understanding of stress and strain relations in complex interplate environments. His award-winning documentary film “The Walls Came Tumbling Down” combined geophysical, archaeological, and Biblical evidence to explore the impact of great earthquakes on ancient and modern societies. He has also lectured widely on “Oil and War” and the risks associated with growing global competition for energy.

The Maurice Ewing Medal is, indeed, an appropriate tribute to Amos Nur for his extraordinary contributions to geophysics.

Biography Citation for SEG Honorary Membership 1996 [2]

Contributed by Gary Mavko

In many circles, the term "rock physics" is synonymous with Amos Nur. Amos has been one of the visionaries who, through scientific innovation, practical demonstration, and a healthy dose of evangelism, has helped bring rock physics from a quiet scientific niche to a critical part of modern geophysics.

A native of Israel, Amos Nur earned his B.S. in geology at Hebrew University, Jerusalem, in 1962. He studied briefly with Gassmann in Switzerland and went on to pursue his Ph.D. in geophysics at MIT.

In his dissertation work, Amos made discoveries that would have far reaching impact. He was the first to observe experimentally stress-induced seismic velocity anisotropy in rocks (i.e., shearwave splitting). He was the first to model quantitatively how stresses influence fracture distributions and how these influence the anisotropy. This was the laboratory and theoretical foundation of virtually all the modern seismic methods for fracture characterization. Amos was also among the first to observe that seismic velocities are sensitive to effective pressures and fluid saturation, which are central to virtually all seismic methods for the detection and monitoring of crustal fluids, including hydrocarbons. Amos earned his Ph.D. in 1969.

Amos joined Stanford's geophysics faculty in 1970. I arrived shortly after that and was lucky to be one of his first graduate students. In 1976 Amos started the Stanford Rock Physics Project, one of the first university-industry research consortia. It helped define the model for fruitful cooperation between industry and academia that is still popular the world over. The project is still going strong, with 28 sponsors. Amos Nur is now professor of geophysics and has held the Loel chair since 1988. He was chairman of the Geophysics Department from 1986 to 1991.

Amos's research and teaching style, then and now, emphasizes individualism, creativity, and breadth. His students have excelled not only in the core rock physics areas of acoustic properties, resistivity and dielectric properties, permeability, and nuclear magnetic resonance, but also in integrated reservoir characterization, environmental geophysics, earthquake prediction, tectonics, and faulting. There is no single "stamp" that marks Amos's work or students except, perhaps, a desire to find simple physical explanations for natural phenomena out of complex, varied, and often apparently conflicting observations. More than 35 students have earned their Ph.D. and 20 their M.S. under Amos's guidance.

Amos Nur has consistently been a visionary. Most obvious, of course, was his vision more than 25 years ago that rock physics would some day play a critical role in extracting rock and fluid properties from geophysical data. To some, his name is synonymous with reservoir monitoring or "4-D" seismology, a hot industry focus today, which he advocated in his seminal paper more than 16 years ago. Today, he is quietly pursuing the energy and environmental implications of methane hydrates, which some estimate contain more organic carbon than all conventional fossil fuels (oil, gas, coal) combined.

What I find extraordinary is that Amos has had similar impact in areas outside of exploration geophysics, always with his trademark touch of innovation, creativity, and (sometimes) controversy.

In the early 1970s Amos was among the first to suggest the dilatancy-diffusion hypothesis as a mechanism for observed seismic Vp/Vs earthquake precursors, spawning great debate and scores of papers. Later, he left his mark on the study of accretionary tectonics, the origins of backarc basins, and the formation of pull-apart basins. More recently, he has shown how the simple rotation of crustal blocks (along with back-of-the-envelope physics) can explain what at first appears to be chaotic arrangement of compressional, tensional, and strike slip features in tectonically active basins. This led to a landmark (and controversial) "anticipation" in 1989 of the 1993 Landers, California, earthquake. His award-winning video documentary "The Walls Came Tumbling Down" combines archeology, geophysics, historical, and biblical evidence to explore the dramatic role of earthquakes in ancient, as well as modern, civilizations. He is also leading a study group on the political, economic, and military impacts of oil on emerging Asian economies.

It is certainly appropriate that the SEG honors Amos Nur for his distinguished career and monumental impact on modern geophysics. I look forward, with great anticipation, to the surprises that he still holds for us.

References

  1. 2010–2011 Honors & Awards Program, 7:30 p.m., Tuesday • 20 September 2011 Grand Hyatt, San Antonio, Texas USA 2010– 2011 Honors & Awards Committee
  2. (1988) Awards Citations of the SEG, Society of Exploration Geophysicists, Tulsa, p. 96.