Peter Hubral, as holder of the Chair of Applied Geophysics at the Geophysical Institute of the University of Karlsruhe in Germany, was among the prime movers behind the restoration of exploration seismology in Germany. This began with the 1980 SEG monograph, co-authored with his mentor Theodor Krey, and continued with Hubral’s truly innovative introduction of the image-ray concept. This led to an early recognition of the need for depth migration. He also became interested in true-amplitude migration, leading to the publication of yet another SEG monograph, co-authored with Martin Tygel and his former student Joerg Schleicher. He also founded the WIT Consortium, the first industrial consortium at a German university. Later, he entered into the more philosophical aspects of science and existence and published a book on the subject. Peter Hubral truly deserves SEG’s highest award because of his outstanding technical contributions and because of the influence he has wielded not only on entire generations of both German and Brazilian students, but on the development of modern exploration geophysics in general.
Biography Citation for the Maurice Ewing Medal 2013
Contributed by Martin Tygel
Peter received his MSc-equivalent degree with distinction in 1967 from the Bergakademie Clausthal, Germany. Sponsored by British Petroleum (BP), he earned his PhD from the Imperial College of the Royal School of Mines, London, in 1970. He started his career at Burmah Oil (Australia), spent time with the German Bureau of Geosciences and Mineral Resources, and in 1986 attained a full professorship at Karlsruhe University, where he stayed until retirement in 2007. His work has been recognized with EAGE’s Conrad Schlumberger Award (1978), SEG’s Fessenden Award (1979), SEG Honorary Membership (1998), and EAGE’s Erasmus Medal (2003).
I met Peter in 1983 at the University of Bahia (Salvador, Brazil) when he arrived as a visiting professor in the newly established graduate program in applied geophysics. This was the beginning of our collaboration and friendship which, after 30 years, is as strong as ever. Peter accepted his duties with remarkable involvement. In a short time, he was speaking and even lecturing in Portuguese. Peter’s 1983–1984 stay in Salvador, followed by numerous visits, is recognized as a landmark for the development of geophysics in the country.
As early as the 1970s, Peter was attracted by Eastern Europe scientific literature, he maintained contact with authors and promoted a few exchange visits. To a large extent, Peter contributed to fruitful East-West communication, in particular during the Cold War.
He has an impressive ability to put complex ideas in simple terms. His concise 1980 book Interval Velocities from Seismic Reflection Time Measurements, co-authored by Theodor Krey, is still an obligatory reference for anyone engaged in seismic exploration geophysics. In that book, one finds Peter’s seminal concept of the image ray (first proposed in 1977), harmonically integrated within the theoretical foundations and practical applications of seismic imaging. Peter is also co-author of three other geophysical books: Transient Waves in Layered Media (Tygel and Hubral, 1987); Elastic Waves in Random Media: Fundamentals of Seismic Stratigraphic Filtering (Shapiro and Hubral, 1998); and True-amplitude Seismic Imaging (Schleicher, Tygel, and Hubral, 2006). In 1997, together with collaborators and students, Peter introduced the common-reflection-surface (CRS) method. CRS is a powerful extension of classical common midpoint (CMP) stacking that is free from the restrictions of CMP gathers. Besides significant stacking redundancy, CRS provides, in addition to normal-moveout (NMO) velocities, other traveltime parameters useful in a number of imaging purposes.
Alone or with co-authors, Peter has made impressive contributions in Kirchhoff true-amplitude migration. Key examples are the concepts of the normal (N) and normal-incidence point (NIP) waves and the unifying approach to seismic imaging, a working platform based on the combined (cascaded) use of true-amplitude migration-demigration operators, seen as a transform pair.
Peter was always eager to disseminate and stimulate discussions of state-of-the-art research. That resulted in the organization of dedicated workshops. Successful examples include ones on true-amplitude imaging (in Karlsruhe in 1997 and 2001) and one on macro-model independent imaging (in Seeheim in 1999).
Besides fully embracing his profession as a geophysicist and educator, Peter has been a passionate humanist, striving for a deeper understanding of the human soul. In particular, the duality of logic and intuition and their role on creative thinking has been a fascinating topic. Retirement from Karlsruhe University in 2007 was for him the opportunity to fully engage into the quest: How do we come up with new ideas? To our delight, Peter once more delivered profound observations on how different societies, Western and Chinese, approach the subject. In the same route, Peter dwelled on the trajectories Plato, Pythagoras and Socrates, and other fathers of modern science, tracing the influence of their long stays in the ancient Orient. As a demonstration on how Peter, once again, captured the attention of the geophysical community, a few papers authored by him on the subject (First Break in 2001, 2004, and 2011, and TLE in 2004) have produced appealing responses.
- Hubral, P., J. Schleicher, and M. Tygel (1996) A unified approach to 3-D seismic reflection imaging, Part I: Basic concepts, GEOPHYSICS62(1):97.