Harold O. Seigel (1924 - 2011) was a pioneering Canadian mining geophysicist who laid the mathematical foundations for the IP (induced polarization) method.
Biography Citation for the Maurice Ewing Medal
The past 40 years have seen a revolution in the state of the art in mining and mineral exploration methods, matching the very significant advances made in oil and gas geophysics. One of the major figures in the field of mining exploration technology throughout this period has undoubtedly been Harold O. Seigel. Harry resides in Canada where there has always been a pressing need for improved methods of exploring the country's vast areas of poorly exposed but nevertheless geologically attractive terrain.
Early Years and Education
Harry earned his BS (1946) and MS (1947) degrees in mathematics and theoretical physics, then his PhD (1949) in geophysics, all from the University of Toronto. His doctoral thesis was a ground-breaking study that remains a classic in exploration geophysics. He focused on the basic concepts and applications of overvoltage (now known as induced polarization or IP), and in late 1948 he conducted the first full-scale field tests of the new method on a known porphyry copper deposit in Arizona. This technique remains one of the primary geophysical approaches used in exploring for sulfide ores and a widely used technique in exploring for disseminated ores (including the primary class of major copper deposits and many types of gold mineralization).
After receiving his doctorate, Harry continued his research and in 1950 developed a mathematical theory which has become the accepted standard for the traditional IP response of disseminated sulfides.
He was also able to demonstrate important practical aspects of IP techniques, which contributed greatly to its increased use. Furthermore, Harry showed in the lab and later in the field that the IP effect could be identified using a series of discrete frequency measurements, rather than a pulse-type waveform. In some cases this approach has advantages over pulse methods. As a result of this work be obtained the first patents in frequency-domain IP.
In 1970 Harry predicted the possibility of measuring magnetic field effects associated with IP and suggested that this approach would offer advantages for detecting ore in some difficult situations, such as the burial of deposits beneath highly conductive overburden. He formulated a theoretical basis for this magnetic induced polarization (MIP) method and developed the technique as a practical field method for use in areas that present a challenge to the conventional electrode IP technique. The MIP method has now been in use since 1974 and has proven to be successful in areas of saline overburden of the type that occurs quite commonly in Australia.
In 1964 Harry became the president and director of research of Scintrex (Ontario, Canada) and in 1991 took on the role of the company's chairman of the board. Throughout this period Scintrex has been a leading manufacturer and developer of exploration equipment and has been the vehicle for the development of many of Harry's concepts which have been reduced to practice under his supervision. During his career, Harold Seigel has been granted 21 patents in six countries, all on developments in mineral exploration technology. He has authored over 40 papers since 1950 and remains active in the exploration field.
Harry has also been heavily involved in the field of airborne geophysics. He and his company have produced an entire range of airborne systems which include in-phase quadrature electromagnetic techniques and rigid configuration airborne systems, such as the Tridem and the dual frequency helicopter-borne electromagnetic systems. During the period of intense uranium exploration, Harry also guided the development of advanced airborne gamma-ray spectrometer systems for use in radiometric surveys. All of these systems have been integrated in various combinations in order to provide comprehensive airborne geophysical data.
Harry has also worked on the development of a ground and airborne version of a laser fluorosensing system that is based on time-resolved photoluminescence. This method has shown promise in the exploration of certain types of deposits, such as zinc, tungsten, tin, molybdenum, and gold.
Throughout his career, Harry devoted much of his time to the successful development of new technologies for mineral exploration, and also played a very active role in convening international symposia in the field of exploration geophysics. Summing up these 40 years of contributions, believe it is very fitting that Harold Seigel should receive the Maurice Ewing Award, since few scientists have contributed as much to the advancement of geophysical technology in the mining and mineral exploration field.
Seigel, H. (1994). ”Some personal reflections on 40 years of KEGS and of mining geophysics.” The Leading Edge, 13(11), 1117–1122. doi: 10.1190/1.1436999