SEG Honorary Membership 2015
Doug Fraser introduced multicoil, frequency-domain EM to the geophysics community. His methods are used to interpret dip and depth of massive sulfide mineral deposits and to estimate apparent resistivity. His methods have become the industry standard. His contributions allow explorers to use airborne EM to look for gold and other targets with subtle signatures which require a good understanding of the surrounding geology.
Biography Citation for SEG Honorary Membership 2015
by Greg Hodges
Many people who know Doug Fraser will be surprised to know that he started out as a geologist, obtaining B.S. and M.S. degrees at the University of New Brunswick. Doug successfully applied for Ph.D. studies in geochemistry at the University of California–Berkeley. His funding, however, came from a research assistantship from the Geophysics Department, and by the time Professor Stan Ward finished with Doug, he had become a geophysicist. Many years later, after cementing his own stellar reputation as an industry leader, Doug would still refer to the geophysical and life advice he had received from Stan Ward.
Upon graduation from Berkeley in 1966, Doug was hired as chief geophysicist of Teck Corp., a Toronto mining company, and was tasked with developing an airborne EM system to replace the company’s Beaver wingtip EM. This led to his founding an airborne geophysical contracting company in 1967 as a subsidiary of Teck. Doug’s group designed and built the DIGHEM helicopter-borne frequency-domain (HFEM) systems and developed the processing software needed to analyze the data. The DIGHEM systems tested many novel multicoil designs with descriptive names such as “whaletail” and “fishtail” before settling on matched pairs of vertical and horizontal transmitting and receiving coils. The number of coil pairs and frequency range were increased several times as materials and electronics improved, and this design has been the standard for HFEM ever since.
Doug’s name is most often heard in reference to the Fraser Filter, an elegantly simple algorithm to convert VLF dip-angle data to peaks over the target for easy contouring, published by him in 1969. The filter demonstrates an important facet of Doug’s genius: simple, effective solutions to common problems. The name Fraser Filter has also been applied to a small suite of filters contouring maps of IP data, and most recently, the effective simplicity of the VLF filter has become the standard tool to present map views of the horizontal component of HTEM data.
Doug’s development of an effective algorithm to convert the DIGHEM data into apparent resistivity, originally designed as conductor detectors for base-metal exploration, led to a significant increase in applications, and it is still the most common algorithm. This development and Doug’s business and scientific acumen for new ideas led to these systems being used throughout the world for water, engineering, diamond, and gold exploration. The development of algorithms to extract magnetic susceptibility and permittivity extended EM to new rock-property measurements.
Doug took the company private in 1984. With his wife, Hemma, keeping an eye on the books, the two often could be found working together, the only two remaining in the office late into the evening. DIGHEM expanded over the years, riding out the tough cycles of the mineral-exploration business and extending its activities beyond North America, particularly to Africa and Australia.
He sold DIGHEM in 1993 to Compagnie Générale de Géophysique (CGG) of France and became executive vice president of the Geoterrex-Dighem division of CGG Canada Ltd. until his semiretirement in 1999. Never one to sit idle, Doug continued to work part time in the R&D group and generally consulting and advising the company for many more years before finally retiring. With more time for Hemma (now married 57 years), their three children, and 10 grandchildren, Doug has been heard to say, “I didn’t think I could be happy without geophysics every day, but I am!”
Douglas Fraser obtained a B.S. and an M.S. in geology from the University of New Brunswick, Canada, and a Ph.D. in geophysics from the University of California at Berkeley. He has been employed in geologic mapping, geophysical exploration in mining, petroleum industries, and geochemical prospecting for base metals. Fraser was CEO of Dighem Surveying and Processing Inc. and later executive vice president of the Geoterrex-Dighem division of CGG Canada Ltd. until his retirement in 1999. Fraser has published papers on copper geochemistry, electromagnetics, VLF, induced polarization, ground and airborne resistivity, digital filtering, correlation techniques, image processing, and new geophysical interpretation methods. He developed DIGHEM airborne electromagnetic systems. Fraser is a member of the Association of Professional Engineers of Ontario and SEG and is past president of KEGS.
- Contributors GEOPHYSICS Mar 2007, Vol. 72, No. 2, pp. Z25-Z35