“Geophysics must play an important role in our future.”

An interview with Doug Oldenburg

Coordinated by: Satinder Chopra
Doug Oldenburg

Doug Oldenburg is a Professor and Director of the Geophysical Inversion Facility (UBC-GIF) and holder of the Teck Senior Keevil Chair in Mineral Exploration at the Department of Geophysics and Astronomy at the University of British Columbia at Vancouver. He is well known for his development of inversion methodologies and their application to solving applied problems.

Doug has won many awards. Starting with the Association of Professional Engineers Gold Medal in 1967, he went on to receive the Carl Ekhart Prize from the University of California San Diego in 1974, share the Gerry Hohmann Award with Yaoguo Li in 1999, receive the NSERC Leo Derikx Award in 2001, and the AMEBC Award for his contributions to Mineral exploration in 2007. He is an Honourary member of the CSEG and SEG.

Doug is the 2011-2012 Fall SEG Distinguished Lecturer and was in Calgary to deliver his talk on October 12th, 2012. The RECORDER did not want to miss out on this opportunity and so requested for an interview. Doug was not overly enthusiastic about the interview, but nevertheless honoured our request. Following are excerpts from the interview.

(Photos courtesy: Joyce Au.)

Tell us about your educational background.

I received a B.Sc. Honours Physics from the University of Alberta. A 4th year course taught by Ernie Kanasewich got me into Geophysics. We worked through the text book by Grant and West. It was intriguing how basic physics could be used to investigate the earth.

At the end of my fourth year Ernie asked if I wanted to work for him for the following summer for a seismic field experiment. They were setting off large explosions in the Great Lakes and the challenge was to record them in Northern Alberta. I gladly signed up. It sounded much more exciting than working at the Canada Packers packing plant where I’d spent my previous couple of summers.

Ernie also introduced me to Ian Gough who had just arrived at U of A. Ian was carrying out research in geomagnetic soundings in large transects across North America. He was looking for graduate students and I signed up.

As a graduate student, I spent a summer in the field. The Mojave Desert in August is a unique environment. We buried 20 magnetometers along 4 east-west lines for a total of 2200 km. The instruments had to be serviced every 10 days. The magnetometer was amazingly simple in principle but required a true artisan to calibrate and adjust it. There were three perpendicular magnets on torsion wires. The magnets would move if there was a change in the earth’s field, and a light, flashing briefly every 10 seconds, would shine on the surface of the magnet and have a reflection recorded on photographic film. The films were processed and transferred to 10 inch wide paper. As a graduate student, we spent a month hand digitizing the three traces of the magnetic field (one dot every 10 seconds for a 48 hour period to capture a single storm event). In retrospect, the whole process was quite amazing. The magnetic fields were then analysed and used to extract information about the electrical conductivity in the earth.

One benefit of working in the Mojave Desert in the summer is that you have little desire to eat. Fluids are sufficient. I ended up losing more than 30 pounds. When I returned, with new clothes, my wife did not recognize me at the airport.

How did you decide to go to San Diego to do your Ph.D.?

I owe this decision 100% to my mentor Ian Gough. I was happy enough in Edmonton (it was home) and I’d have liked to finish a Ph.D. there. Ian however felt it was better for me to go abroad and he arranged for me to go to the IGPP (Institute of Geophysics and Planetary Physics) at UCSD. Not only that, but he also arranged with Walter Munk to have me go on full scholarship. This was all done prior to him talking to me. Ian was therefore pivotal in my career path and I am eternally grateful for his mentorship.

What kind of research were you involved in at UCSD?

Sea floor spreading was the hot topic of the day. The idea that the earth could be in a convective state was a bit mindboggling and scientists were debating the pros and cons. Ocean-going vessels were recording the magnetic stripe patterns on the ocean floors, and also heat flow measurements were being acquired. Scripps (Research Institute) and Woods Hole (Oceanographic Institution) were the preeminent centres. At the time it was natural to participate in this area of research.

My thesis research was made of two components. My supervisor was Bob Parker who had just arrived at Scripps and he accepted me as his first graduate student. With Bob, I focussed upon developing a mathematical model for the thermal structure of an expanding lithosphere. The second component was associated with Jim Brune, a seismologist. It was a bit of serendipity. Jim was helping his kids make candles and discovered that a thin skin of newly solidified wax could be made to exhibit many of the features of lithospheric plates. That is, you could use them to make spreading ridges and transform faults. I ended up doing laboratory work with a variety of materials to characterize the phenomenon and then tied the results to the theoretical predictions to show that the thickness of the lithosphere should increase as square root of time.

So that was my thesis research, but my career in inverse theory really started simply because I was at UCSD at that particular time. George Backus and Freeman Gilbert were doing pioneering work on the fundamentals of inverse theory and its application to normal modes of the earth. George was brilliant but his mathematical proofs and presentations were not for the faint of heart. Bob Parker was the person who translated everything into a framework that was readily understandable and immensely practical. His work, which culminated in his book, Geophysical Inverse Theory, stands out as a major achievement in the field. As a graduate student, and particularly Bob’s student, I benefitted immensely from his work and it formed a foundation for my subsequent career.

After graduating in 1974 I returned to Edmonton as a postdoc. It was there that, because of Ian Gough, I began work on inverting DC resistivity data and MT data. I also worked closely with the space physics group headed by Jack Jacobs and Gordon Rostocker. We deployed magnetometers in northern Alberta to record currents associated with the auroral electrojet. The solution of the inverse problem showed that the current magnitude was immense.

I notice that since you joined UBC in 1977, you pretty much stayed there all through your career. There must have been compelling reasons for this?

I wanted to stay in Edmonton, but there were no openings. I accepted the job at UBC in the Department of Geophysics and Astronomy. I love the prairies, but once you’ve lived in Vancouver it is exceedingly difficult to leave. Most importantly, the department had a good profile internationally and attracted excellent students. It wasn’t long before I had a suite of excellent students. With a good research group and a stellar location, it wasn’t possible to contemplate leaving.

Looking back now what do you have to say about how your career shaped up?

Career paths are random walk processes. A chance meeting, an interesting talk, a paragraph in a journal, a picture; all of these things can launch you in a new direction. I was fortunate to have a background in inverse theory and this is applicable in all fields. So, I had a tool kit, and it was easy to attach myself to a variety of different projects. If the problem could be written as a Fredholm equation of the first kind then the path toward a solution was straightforward. So the ultimate trajectory is charted by the people with whom you interact. For me it was Bob Parker for an initial gravity inversion problem, Ian Gough for DC resistivity and MT, students like Tim Scheuer and Shlomo Levy who had worked in the oil industry, and a cadre of geophysicists working in the mining industry. I think the most important item was the establishment of the Geophysical Inversion Facility in 1989. That has provided a structure for carrying out my research for the last few decades. The goal, to develop inversion methodologies and apply them to help solve applied problems in exploration, environment and geotechnical areas, allows a large variety of problems to be tackled.

What personal qualities do you think helped you achieve all that you have achieved? Please share with us one or two of your most exciting successes.

That’s a hard question. My success is primarily attributable to the amazing students, postdoctoral fellows and research associates that have been in my group. My role, especially in the most recent years, has been to ensure there is funding, and to provide an environment where people can work individually and collectively to solve interesting and important problems. I also have the benefit of many years of experience that helps prevent us from “rediscovering the wheel” and helps put our proposed research into a proper context.

One highlight was the development of a way to invert induced polarization data. Prior to formal inversion, data were interpreted by looking at pseudosections. But those are just plots of the data and it is only under rare circumstances that you can discern the underlying geologic structure from those pictures. The amount of information that could be achieved by carrying out the inversion illustrated definitively the value of rigorously inverting the data. Also, it quickly became clear that much previously collected data, which had been considered to be too noisy to be interpretable, were now valuable.

Tell us about your teaching. What courses have you taught at UBC over the years? In the citation that was written for you when you received the 2001 SEG Honorary Award, Professor Yaoguo Li wrote that you are an outstanding educator with a unique style of lecturing and mentoring and that you impart scientific rigor and integrity while being exceptionally warm and caring. I think this is great compliment. Please share with us your take on all this.

That is a nice complement and perhaps it tells more about Yaoguo than about me! I love teaching and I take it seriously. There is a huge satisfaction in being able to look someone in the eyes and see that he/she really understands. As to the courses, they have ranged from inverse theory, time series analysis, whole earth geophysics, and numerous courses at different levels in applied geophysics. This term I’m teaching a general course of applied geophysics to engineers, geologists and other non-geophysicists. This is an important group to work with since they will be in the position of deciding whether geophysics should be used for their problem. They need to understand enough about the basic principles to ascertain which, if any, geophysical survey might be useful and what to expect from the result. Too often geophysics has been over-sold to potential clients and this has had a long term negative effect in some areas. The real challenge here is to get the engineers and geologists to think and formulate their problems within the context of physical properties.

I am sure you have an impressive list of graduate students you supervised. How many M.Sc. and Ph.D. students have you supervised? Please tell us about some of them who have done really well, though I am sure each one of them has.

I have supervised 19 Ph.D.’s and 18 M.Sc.’s during my career. That may not be a particularly big number since I’ve been at the university since the end of the last ice age. I’m very proud of my students. They have done well and no one left the group without having a job they were truly excited about. Five former students are in academia, some established their own companies, and others are working in industry or government labs. They are almost all still working in the geosciences. Some specific names you might know are Peter McGillivary, Yaoguo Li, Eldad Haber, Peter Fullagar, David Lumley, and David Aldridge but there are a host of others.

Your early research in seismic impedance inversion led to the creation of the software package Inverse Theory and Applications (ITA) and I know at one time it was used to process seismic data as well. I believe you were the President of that company. Please tell us about that effort and what the fate of that package was.

The early 1980’s was an exciting time for geophysics. Computers were becoming smaller in size and more powerful but the real revolution was the computing workstation. In order to use them a new suite of software had to be written. The architect for that was Shlomo Levy who had previously worked in the oil industry and knew what needed to be done. We also had a great technical team, mostly from UBC, who put the ideas into reality. The final product, Insight, was used for processing by ITA but also used by the Lithoprobe group for their large scale reflection seismic transects. ITA was sold to Landmark Graphics and the code was absorbed by them.

What areas of geophysics interest you more than the others and where are your research efforts focused? I know you are regarded as an expert in geophysical inversion, but you may have focused on some other areas as well. Also, your research focus shifted from hydrocarbon exploration to minerals; I would be curious to know why.

Our research about inverting band limited reflection data to recover the acoustic impedance was very exciting for us. However, it was difficult to acquire data from companies and details about the data if you did get some. It was also difficult to get companies to take unknown academics seriously. That was a motivating factor for the development of ITA. It was envisioned as a place where applied research could be more readily carried on. In a sense that was true. The real advances in applied research arise when working with field data sets for which there is a clear geophysical or geologic goal that can be achieved with the processing or inversion. ITA provided an opportunity to be more connected with industry and also an environment in which to carry out research. However, a company also needs to be concerned with cash flow and for a number of our initial contracts we found that there were many interesting problems to be explored but further time could not be allocated. So an industrial company is not necessarily a panacea environment in which to carry out wide ranging research.

By the time ITA moved to Calgary in 1987, I had revised my thoughts about where good research in applied geophysics could be carried out. A university setting can be ideal but there needs to be close cooperation with industry. The province of BC was also thinking this way and I was awarded money for computer workstations (which were astronomically expensive compared to today’s standard) to set up the Geophysical Inversion Facility (GIF). The mandate of GIF was to develop new technological tools for the mining industry. Our first serious project was to work on a 3D inversion of E-Scan data. This was a novel DC resistivity experiment in which an area is blanketed with electrodes. Each electrode gets ignited with a current and potentials are measured at the remaining electrodes. Greg Shore, who invented and deployed the system, was a visionary. Despite the fact that we were successful in developing inversion algorithms to invert the data, the company went into receivership and I was faced with an inability to pay salaries. So carrying out research at a university but interacting with a single company can be risky.

It was then that a moment of serendipity arose. A group of chief geophysicists from Placer Dome, BHP, Noranda and Cominco organized a brain-storming meeting at UBC to see how best to interact. Out of that meeting came a plan to carry out research to invert the various types of geophysical data collected for mineral exploration. The theme would be Joint and Cooperative Inversion of Geophysical and Geological Data (acronym JACI). A consortium of ten companies joined the three year project and funds were matched by NSERC. JACI was extended for another three years and by the end of the 6-year project we had developed software to invert DC resistivity, IP, gravity and magnetic data in 3D. Two of my research associates, Yaoguo Li and Rob Ellis contributed greatly to the overall success of the project. The consortium keeps going today with many of the same sponsors, although their names have changed because of mergers and buy-outs.

This is a bit of a long winded answer but I think it sets the proper background. The mining industry had a set of problems that could not be answered without the formal mechanisms of inversion to unravel their data. Moreover, their problems were often characterized by reasonably large signals. Lastly there was a spirit of cooperation among the companies that was unique. Even though they were competitive at the exploration level, they were willing to cooperate at the research level with the vision that if we could produce technology that was helpful for the industry as a whole, then it would also be helpful for them. For that reason they freely shared ideas, case histories about the application of inversion, and decided among themselves which survey types should be prioritized in our research program. Lastly, there were a few companies that immediately used our software out on their field data as soon as the software was released. This feedback helped us greatly in seeking out weak links and ultimately developing software that was useful. So over the last two decades my mineral-linked research focus has provided funding, data, close interactions with industry and an end user who has substantiated the value of the research. There was simply no reason to alter this interaction. But within that context our research has tackled progressively more challenging problems that are of use in mineral exploration and elsewhere. Our most recent achievements pertain to the 3D inversion of electromagnetic data. I’m very excited about this. Electrial conductivity is a major physical property that can be diagnostic for a wide variety of problems at different scales. It has applications in hydrocarbon and mineral exploration, and in environmental and geotechnical problems. It can be used to detect small scale objects like UXO (Unexploded Ordnance) or the large scale structure of the earth. It is a complementary data set to seismic and it is especially valuable in delineating the geology of the top kilometer or so. The ability to invert EM data to recover the 3D electrical conductivity structure opens up a host of potential applications. You will see much more about this technique over the next decade.

If I say your most important contribution to geophysics is the development of geophysical inversion, whether applied to hydrocarbon or mineral exploration, would you agree, or there is more to it?

The field of inversion in applied geophysics can be thought of as a large wheel with many cogs. Perhaps I am one of them. In the long term however, I think my most important contribution has been to provide an opportunity for young scientists to explore their creativity in solving relevant problems and to provide that close link between the university and industry. The best research has resulted from having industry data and associated problems. So I think that the long term impact is the cumulative effect of all those who have come through the GIF group.

What personal and professional vision have you worked towards throughout your career?

I want to see geophysics used responsibly and have it make a difference in solving problems of relevance to our society. Geophysics is a discipline that is intimately concerned with imaging the earth’s interior without directly sampling. Each object or rock type has its own fingerprint of physical properties. If we can discern that fingerprint by inverting data from many different types of geophysical surveys then we should be able to answer many problems that arise in resource exploration and in environmental and geotechnical problems. This is important now and the use of geophysics will become even more important in the future.

You also established the UBC-GIF Outreach Program in 1997, which was aimed at disseminating inversion algorithms and also educating practitioners and non-specialists about inversion uses and benefits. Please tell us about that initiative.

Francis Jones (Outreach Coordinator for GIF) and I put together the IAG (Inversion for Applied Geophysics) CD that tried to outline fundamental principles of inversion and also provide software so that people could learn by inverting various types of geophysical data. There were also numerous case histories and ancillary information about the geophysical surveys on the CD. The feedback from people who have taken the time to download and work through the material has been very favorable. A number of universities have made good use of the material. The package can still be downloaded from UBC Flintbox. If time constraints ease it is still one of my goals to update and improve this package. Two additional avenues were sought to get our technology into the private sector. The codes, ready for commercial processing, were, and still are, available through a license agreement. We have three third party companies from whom our codes can be licensed. Lastly, academics can obtain the code without charge for research purposes.

You have written and published many, many refereed research papers. Ever thought of writing a book on geophysical inversion?

Writing a book is a big undertaking. I’ve contemplated it a few times but rather than write a traditional book I wanted to generate something that had more layers and was interactive. The IAG CD was an attempt to achieve this. It was structured so that someone who didn’t know much about geophysical surveys or inversion could get some background. Or if you wanted more information about inversion, or actually wanted to attempt to forward model and invert data, then that too was available. I still think such a product would be valuable and, as I said earlier, one of my goals is to revisit this.

What is your impression about the current state of the Canadian universities, in general and then with respect to Geophysics in particular? How do they compare with other North American and European universities? You may also like to include in terms of the funding, problem-oriented research, dearth or abundance of students, etc.

This is also a difficult question. For people like myself who have an established research program with strong ties to industry, the research environment and funding are good. This is especially so because of federal government initiatives that are attempting to foster industry-relevant research. I think the funding issues are much more difficult for incoming geoscientists who are carrying out “curiosity driven” research or dealing with problems for which special funding avenues don’t exist. When I started my career my personal operating grant (now called Discovery Grants) was sufficient to support a couple of students and take us all to a conference. Today, that would be a significantly sized grant in the NSERC system. I don’t have substantive information about how Canadian universities are faring compared to North American and European universities. Overall, I believe that the earth and ocean science department at UBC continues to grow and I’m pleased to report that the geophysics program, which had a dearth of undergraduate students for a decade or more, is growing significantly. We hope this continues. At the graduate level, we have generally been able to attract high quality students in reasonable abundance.

What sets UBC apart from other universities in Canada? What is it that would attract students to come here? What is the focus of research here?

The one advantage that UBC has is the setting. The climate is moderate (no -40F with howling winds), the vegetation is lush, lawns are green yeararound, and there is access to mountains, ocean, beaches, forests. People who like the outdoors gravitate to UBC. I know that because I have had a number of students and postdocs who wanted to join my group and, after accepting them, I found out the major reason was that they wanted to live in Vancouver. It was a bit deflating. There is an upside for the physical activity that Vancouver promotes. Exercise is a perfect balance to mental/computer programming efforts. In my group I have triathletes, marathoners, curlers, snowboarders, cyclists, and ironman participants. Not only do they participate but they also excel.

Of the many different awards that you have received, which one is the most dear to you and why?

Well, I haven’t really received that many awards and I’m not particularly fond of being in the limelight. It is however gratifying to receive an award because it indicates that people value your work and maybe the work does make a difference. In the end, I think we are all trying to contribute to the betterment of the field in any way we can and awards give us some affirmation that we are on the right track.

Tell us all about your experiences so far as the 2011-2012 SEG Distinguished Lecturer?

Finally an easy question! I haven’t yet given a lecture and Calgary is the first stop on my tour. I could answer your question better in another 8 hours. It is an honour to be chosen as a Distinguished Lecturer and we have a great tour planned for this fall and next winter. I look especially forward to visiting universities and talking to students. There are so many interesting and important aspects to applied geophysics and it would feel very good to inspire young scientists.

What other interests do you have?

Another easy question. I love to cook. It’s creative, challenging and provides an opportunity to be connected with my wife and family. And, of course, there is the pleasure of eating foods with different flavors, aromas and textures. Another, perhaps related, passion is trying to keep sensibly fit. We discovered yoga a few years back and it has been extremely beneficial for our health. Our yoga is not meditative; it’s the hot yoga, with 1 ½ hour classes in a 115F humid room. It’s a total detox combined with interval training. By combining yoga with cycling, resistance training, and good nutrition we’re hoping to delay our arrival in assisted living quarters. Lastly, another important aspect of our life is our grandchildren. All the clichés about grandparents are true. It is a marvel watching children grow up and a privilege to be part of their development.

What would be your message for young geophysicists entering our profession?

I reiterate a theme. We are living in a crucial moment in the development of our civilization. The potential for doing irreparable harm to our planet is very real and at the same time we need to extract resources and sculpt the outer regions of the earth to build our society. This is a delicate balancing act. But irrespective of the objectives and concerns related to exploitation, the environment and geotechnical work, there is going to be an ever-increasing need to determine what is inside the earth without direct sampling. Almost by definition, geophysics must therefore play an important role in our future. To be successful the geophysicist needs good communication skills so that he/she can effectively work with geologists and engineers who are working on the problem. This allows geophysics to be used responsibly. The geophysicist also needs to have high computational skills so that the complicated systems of partial differential equations that govern time-dependent processes with the physical properties can be modelled and data processed or inverted. Thus there is a spectrum of attributes that is potentially demanded and students with these capabilities, and the desire to solve relevant problems, can find a rewarding niche in geophysics.


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