The Society of Exploration Geophysicists in 1991 honors with SEG's highest award, the Maurice Ewing Medal, a scientist who, though having found his metier by accident, was able to combine the theoretical aspects of geophysics with the practical ones. In
fact, this combination, in which the driving force was always well-balanced between theory and application, resulted in continuous contributions to exploration geophysics, spanning a time frame of roughly 55 years. The third important factor (without which no breakthrough is achieved) is creativity, and it can be claimed that Krey is a person of extraordinary creativity.
These aspects have been recognized in Germany, Europe and the US, resulting in the following well-deserved honors:

1952 SEG Best Paper Award

1969 EAEG President

1972 Title of professor granted by the senate of Hamburg

1979 Schlumberger Award, EAEG's highest honor

1981 SEG Honorary Membership

1984 Renaming of the Rayleigh-channel wave into Krey-wave

1986 Honorary Member of the Hungarian Geophysical Society

1988 EAEG Honorary Membership

1988 Title of Dr.rer.nat.h.c. granted by the faculty of geosciences at Ruhr-Universitat Bochum, which (again) is their highest distinction.

These awards have been given for two categories of reasons, i.e., either for a particular contribution or for overall recognition of the various innovative ideas of Theodor Krey. Here the SEG Best Paper Award resulted from a paper dealing with diffraction effects, the name Krey-wave was given as a recognition of Theodor Krey's in-seam seismics activities. (In that content it should be mentioned that Evison was honored in a similar way by renaming the Love-channel wave into Evison-wave.) The title professor was due to his teaching activity (topic: applied seismics) parallel to his main job at Prakla-Seismos.
Born on 17 August 1910 (Freiburg/Elbe), descending from craftsmen on his father's side and mariners on his mother's side, Krey almost had become a sailor, but financial grants by Bremer Stipendienverein (for the first semester) and the Franz Schutte-Stiftung (for the remaining semesters, fortunately for our profession) allowed him to attend the university in Gottingen, which was the mecca of science at that time, and partly that of Munich. These college years of 1928-32 were devoted to mathematics, physics, and geography. Among his academic teachers one finds famous names as Arnold Sommerfeld, Max Born, David Hilbert, Richard Courant, Edmund Landau, and Gustav Angenheister.
In this period he had the opportunity to experience a discussion on Alfred Wegener's theory of continental drift, where a famous geologist still denounced it. This event took place at a combined geologic/geophysical colloquium at about the time Wegener died in Greenland. In 1932 he became a teacher at secondary schools, but in 1936 he decided to join Seismos GmbH. After a short interruption caused by the Second World War, he started again and continued his career from party chief to supervisor and finally technical managing director at Seismos in 1954, i.e., after the death of his boss and friend, Dr. Luckerath. In 1963 Prakla and Seismos united, and as a consequence Krey also assumed responsibility for the whole scale of scientific supervision of the
crews of both companies, including data acquisition, processing and interpretation. In this year he also was engaged as a Uno consultant for a short time in New York and Bolivia.
The latest course which he held in exploration seismics was in 1984 in Bahia, Brazil. Nowadays he is still asked for consultations from time to time, especially when problems related to the deep crust and to KTB (deep continental drilling) are discussed.
My first contact with Krey was in 1967, starting with the topic of undershooting, a method which continuously is in use since then, and which was subject to continuous refinement as well. Reviewing Krey's output, one should recognize that he is one of the few scientists who fortunately never specialized i.e., who was (and is) active in the fields of data acquisition, processing and interpretation, and thus never fell into the traps of playing the part of manager.
He considered applied seismology as his great challenge, which resulted in numerous publications on topics as velocities (Dix-Krey formula), refraction effects, undershooting, 3-D seismics, anisotropy, vibroseis, resolution, S/N ratio improvement, and many more.

In 1980, co-authored with Peter Hubral, an SEG monograph was published, which is only No. 63 in the list of his publications.
The amusing aspect here is that Krey officially retired in 1975, but he continued his work and kept a close relationship to Prakla-Seismos and (after the take-over in 1991) to Geco-Prakla. We still have our weekly discussions in Hanover, and it is a great honor for me to congratulate Theodor Krey in the name of SEG on this well-deserved award.

Roland Marschall