To get the right feeling for Guus Berkhout's standing in the geophysical industry, you should walk with him through the SEG Exposition. Your conversation will be interrupted every few meters by somebody who wants to talk to him or simply say hello. This is one of the situations in which you come to realize the enormous appreciation for Guus, both as an eminent scientist and as a personality.
     Guus started his geophysical career in 1965 with Royal Dutch/Shell, where he developed integrated seismic and petrophysical methods for direct detection of oil and gas. After having moved through various research and management positions, he accepted in 1976 the Chair of Seismics and Acoustics at Delft University of Technology. Now, 28 years after his professional start, he can look back on what is perhaps one of the most significant scientific contributions any individual ever made to the geophysical profession. In terms of volume: One hundred four journal papers, 71 conference proceedings, 95 abstracts, and 12 books. His monographs on seismic migration and seismic resolution are standards with a worldwide distribution. In his faculty he supervised more than 100 MS and 25 PhD theses. Five of the latter received a cum laude distinction, a rare honor at Delft.
     In terms of seismic innovation, the record is, if possible, even more impressive. In the late 1970s, Guus already perceived the importance of depth migration and presented the physical principles and practical applications at industrial seminars all over the world. His work can be ordered into 11 main fields in each one, he made significant contributions. Some of the best known are the introduction of the WRW model in processing; migration per frequency component; wavefield extrapolation in terms of convolution, and Fresnel zones in terms of spatial wavelets. In his 50-people department, real-time imaging is also being applied to medical diagnostics and ultrasound inspection. There is also a group working on wave field synthesis and its application to acoustics in concert halls as well as in living rooms (superstereo).
     In recognition of his work, Guus received the Conrad Schlumberger Award of the EAEG (1981); the Fellowship of the Dutch Forum for Science and Technology (1988), and membership in the Royal Netherlands Academy of Arts and Sciences (1990).
     As a teacher, Guus has the gift to make you feel comfortable with extremely complex subjects.
     I am one of the many people who has attended a Berkhout course. In my case, it was "Seismic Data Processing," in 1976, and I shall never forget the combination of scientific depth, enthusiasm and wit that he kept up throughout a very intensive five-day course that left everyone but the instructor exhausted. These same qualities created the special culture in his department in Delft. His students not only receive excellent training on a solid fundament of physics but also adopt the special behavior that is so characteristic for the "Berkhout School" and makes them a target for corporate recruiters.
     A third facet of Guus' personality formed by his skills as manager and consultant. He was a cofounder of Jason Geosystems and Delft Geophysical (now part of Geco-Prakla). He is much in demand as a consultant and he is a member of several advisory boards such as the Netherlands Organization for Applied Scientific Research TNO and the Institute Delft Geotechnics. He is editor-in-chief of the new Journal of Seismic Exploration. His many and varied contacts with industry are considered vital at Delft University, where we believe that technological research is more relevant when conducted in close contact with the practical world.
     Guus has, of course, been involved in the organization of several conventions. He was, for example, chairman of the organizing committee of the 50th Conference of the EAEG at The Hague. He set up an exceptional conference: One day longer than usual, daily free lunch for all delegates, a dinner-dance with five bands, free drinking and dinner, and so forth all for exactly the same registration fee as usual. On top of that, he succeeded in turning in a record financial profit. This conference was historical also in another respect: At the farewell party, the delegates were treated to the first performance of the EAEG Jazz band, a swinging affair under the direction of piano player Guus Berkhout. Yes, he is also a gifted pianist and often, when in a restaurant or lounge, he cannot resist the urge to sit at the piano and play a medley of jazz evergreens. I have frequently witnessed enthusiastic people, upon leaving, give him a generous tip which he accepts with just the hint of the devil in his eyes. To completely baffle the reader, I can add that Guus is also an excellent tennis player.
     Back to our profession: His scientific qualities and management skills are apparent in his function as director of the Delphi project, which is supported by a consortium of 20 oil companies and seismic contractors. Next year, I suspect, Delft University will appoint him as director of the new Graduate School for Technical Geosciences. In this school, four faculties and five national research institutes will cooperate.
     Guus Berkhout is a many-sided man and an international personality. But, first and foremost, he is a professional and an eminent geophysicist. We honor him for all he has done for the science of seismic exploration. It is most appropriate that he is being awarded Honorary Membership in the SEG.

     Nico de Voogd