“Keep studying, keep learning...”

Dave, I would like you to speak a little about your educational background and work experience.

After receiving a B.Sc. in Physics in 1977 from Texas A&M University, I worked with Western Geophysical, first on a seismic crew in Venezuela, and eventually in their research group in Houston. In 1979 I began graduate study at Stanford, worked with the Stanford Exploration Project, and after receiving a Ph.D. in Geophysics in 1983 I began working with Chevron. In 1988 I joined the Colorado School of Mines as an Associate Professor. I returned to industry in 1992 to work with Advance Geophysical as their Chief Geophysicist. After Landmark acquired Advance in 1994, I eventually worked as a Senior Research Fellow until leaving Landmark in 2005, when I returned to Mines as the C.H. Green Professor of Exploration Geophysics.

After getting your B.Sc. in Physics from Texas A&M University, how did you decide to come to Stanford and switch over to Geophysics?

My introduction to geophysics came from that first job with Western. When I began working with their research group, surrounded by folks with Ph.D.’s in various subjects, I soon realized how much I had to learn. I actually kept a list, Things Dave Does Not Understand, and that list grew faster than I could check things off. The list included concepts from Jon Claerbout’s first book, Fundamentals of Geophysical Data Processing, and after meeting some of his students at an SEG meeting, I decided that it was time for graduate school.

You seem to have a varied experience, first with Western, then Chevron, then with Advance Geophysical/Landmark Graphics and finally at CSM. What you do have to say about it?

I have had wonderful opportunities to work in several different contexts, including a service company, an oil company, software companies, as well as academia. Every time I left one position, it was because there was something that seemed almost irresistible about the new one. And although I have ended up in academia, I very much value the years in industry; at Mines those years enable me to teach from experience.

You have received many awards for your work, including the prestigious SEG Virgil Kauffman Gold Medal. What personal qualities do you think enabled you to achieve the professional status that you enjoy today? Is it hard work, ambition, or anything else? Do you think it is having a firm grounding in some of the basic concepts that has kept you in good stead or is it something else?

Education was important, of course, and most people think that I work a lot. But I try really hard to keep that work fun, so that working hard is for me really just playing hard. And I am careful to not let other people push me into too much of the other sorts of work in which I would have less fun and be less productive.

You have received many awards for your presentations at the SEG Convention and other events. What do you attribute the success of these presentations to – is it the way you articulate the information, is it your command over the language, or is it something else?

Not my command of the English language; I speak rather plainly! For me the recipe is simple. Have something important to say, and be a teacher when I say it. Importance is subjective, but it would be difficult for me to speak well about just anything. I need to have something that I really want to share with my audience. And then I spend quite a bit of time thinking about how I am going to explain it in a way that almost everyone in the audience will understand. That’s what I mean by being a teacher.

A turning point for me was when I began looking to see if the audience was getting it, and caring less about whether or not I would forget my lines.

I often talk out loud to myself about research while walking to catch my bus early in the morning, as if I am giving a presentation. This may be for research that is far from complete, so that sometimes I realize that my explanation does not make sense even to me, which likely means it’s wrong. My point here is that months later when I speak to a real audience, I’ve probably used similar phrasing many times.

My first presentation to an audience in geophysics was at the Offshore Technology Conference in 1979, when I worked with Western Geophysical. Ken Larner had already presented the same work at the previous SEG meeting, but for some reason he gave me the opportunity to do this at the OTC. But first I had to do a videotaped rehearsal at Western, and at the end of that Ken praised my effort, claiming that I must have done this sort of thing before, which made me feel pretty good at the time. He then asked if we might review the videotape together and of course I agreed. THREE HOURS later we completed that review of a 15-minute presentation. I cannot remember anything Ken told me during the review. What I do remember is that the leader of Western’s research group thought it was important to spend three hours teaching a young kid how to speak well, when he could more easily have given the talk himself.

Who have been some of your mentors?

So clearly, Ken Larner, in many ways. And Jon Claerbout at Stanford, who forced me to work through research problems on my own, to get confused and then find my own clear way out of that confusion, which greatly increased my self-confidence. Rutt Bridges taught me that there is much more to a successful business than a good idea.

Vern Herbert at Chevron influenced the way I work in many ways. I first learned about Vern’s development of the FFT while at Western, but had never met him before joining Chevron at their research lab. My wife Laura and I had probably been working there less than a month when I called Vern to invite him to visit and lecture about anything he wanted to talk about. I didn’t care what he talked about; I just wanted to meet the legend. During that phone conversation I asked Vern why he was not working at the research lab. His immediate reply was, “I don’t want to waste my life.” This helped me to realize that the only way I was going to be able to have an impact at Chevron was to do both the geoscience and the computer science, that I had to become really good at both so I could implement my own ideas, that I could never simply throw great ideas over a wall and expect someone to implement them in ways that others could use. Vern was always willing to share with me his solutions to computational problems; I learned so much from him.

Tell me about Dave, the person- i.e. your habits, your likes/dislikes, etc.

I get up early and go to bed early. Always have, even in graduate school. I think that part of the reason I do this is that I need a lot of quiet time alone. On any psychological test for introverts and extroverts, I am at the extreme introvert end of the scale. I like going for a run with a friend, and dislike large social gatherings.

Tell us about your contributions to Geophysics, as I believe that is what is close to your heart.

Every significant bit of work I’ve done in geophysics has had a significant computational component. I love writing software. In graduate school this meant learning computer graphics and assembly language programming for an array processor. At Chevron this included programming six disk drives to read data asynchronously, so that turningwave migration would run overnight on their Cray supercomputer. The theory and analytical work was both necessary and insufficient. To have an impact, it had to be implemented well so that others could use it.

So what areas of geophysics do you like better than others? Do you plan to focus your research on these areas or do you like to pick up whatever catches your fancy?

It’s probably obvious by now that I often choose problems that require computing skills, because I may have an edge in finding and implementing solutions. Most recently I’ve enjoyed working in the seam between seismic imaging and interpretation.

What has been the most memorable moment in your professional life? Also, tell us about some of the successful landmarks in your geophysical career.

A most memorable moment at Chevron was when we imaged thin salt intrusions in faults radiating from a salt dome. Geologically such salt intrusions made sense, but I had never seen them imaged and so did not recognize them. I thought they were artifacts, that my software had a bug. But fortunately someone who understood geology was standing next to me. That was Chris Dale, and he was the one who recognized these skinny salt intrusions in the image.

What made this experience memorable for me was that seismic imaging revealed something I had not even known to look for, something unexpected. These experiences are rare.

What are your aspirations for the future?

Become a better teacher, not just in the classroom, but also in research. I continue to make mistakes, to do things that make learning more difficult than necessary for students. The good news is that every year I get a do-over. This year I’ll get it right.

Please permit me to ask you this. What differences did you notice when you turned 30 years, 40 years and 50 years old? As an example, some people think their 30’s allowed them to experiment with options, the 40’s gave them time for self-introspection, and I’ve even heard some people get naughty at forty. Your comments?

I’ve never heard this, or at least don’t remember if I have. I also cannot remember my 30th and 40th birthdays. I do remember well my 50th birthday, because on exactly that day I contracted the shingles virus, which is like the sequel to chicken pox. For me this was a warning sign that the warranty on my body had expired. Today there is a vaccine for this; seems like a good idea.

You are now the Director, Center for Wave Phenomena, Colorado School of Mines. Please tell us about, the type of work that is being done in your Center and how many people are engaged there.

D: Directing CWP is very much a shared governance among our five active faculty. Jyoti Behura recently joined Ilya Tsvankin, Roel Snieder, Paul Sava and me as a research professor, after working for two years with BP. We have over 25 graduate students, and a few post-doctoral fellows as well. So we have a lot going on. Our research is diverse, and reflects the diverse backgrounds and interests of our faculty and students. While we may work on rather different research problems, we all share the sense that our work must be relevant to our sponsors.

What is it about CSM that appealed you so much that you decided to settle down there?

In both my first and second lives at Mines, the primary appeal has been the opportunity to be a teacher. I’ve had wonderful research experiences in industry, so that was for me never a significant reason to work in academia. Also, Colorado is a special place; Denver is of course much like Calgary, so you know what I mean.

In 1989 you received the SEG Virgil Kauffman Award for your work in DMO. Gradually DMO has faded with PSTM taking its place. I also remember your work on the maximum likelihood approach for Q compensation. Thereafter you moved to atomic meshing and full waveform inversion, etc. For the benefit of our members, please tell us about all these contributions.

Seismic imaging is based on a large number of approximations. Even today we cannot afford to implement precisely the physics that we know. Years ago DMO was a useful approximation, but today is mostly unnecessary because with better computing hardware we can afford better approximations. Beyond PSTM, reverse-time depth migration is now becoming widely used. So the trick is to know which approximations are the weakest links, which assumptions are worst, and to get rid of those first.

What are the directions R&D in our industry are focused? Any particular revolutionary technology around the corner that will help us in a big way?

I am most easily impressed by things I do not understand, things far removed from what I am working on, and new methods for seismic acquisition are among those things. Closer to my own work, the most revolutionary technology is related to multicore computing systems. We teach classes at Mines with the name “parallel computing”, which is sort of strange, because today there really is no other kind. Array processing is relatively easy to make efficient on multicore systems, but is rather limiting in the problems it can solve. So I think that revolutionary changes in the way we program computers are both necessary and possible.

I would like to know your perception about writing; I see you have many papers published in geophysics and many more must be submitted. How do you do all this?

Actually, I write more software than prose. This was naturally even more true when I worked in industry. I never feel bad about this, because I enjoy programming – I’m good at it, and software is the least ambiguous documentation of a new algorithm. Peer review is important, but in some ways the software I have written may have had more of an impact than my papers published in Geophysics.

I notice you have been invited to deliver lectures at the SEG Meetings, but you have not held any position on the SEG Executive Committee. Any specific reasons for this?

I see these as different activities requiring rather different skills. I have learned how to deliver a lecture, but have no idea how people are nominated for SEG Executive Committee positions. That alone suggests that I lack the required skills for the latter.

What are your other interests?

You mean beyond teaching, computing and geophysics? I am the faculty advisor for varsity swimming & diving at Mines, which gives me the opportunity to hang out with some amazing student athletes. I still enjoy competing, and swimmers at Mines give me a good beatdown. I used to play the banjo. My banjo playing has been a sort of barometer for my career. When I would get bored with some aspect of my job, I would play more banjo and get better at it. I’ve hardly touched my banjo since returning to Mines almost eight years ago.

What would be your message to young entrants who have just taken geophysics as a profession?

Keep studying, keep learning, of course. Do whatever you can to find a job that is so much fun you would do it for room and board. But you will make money, because your skills are valuable. And you will save money, because you won’t have time to spend it. Work most closely with others who share your enthusiasm.

One last question, do you think I missed out on any question, that you expected me to ask and I did not?

I thought you might ask me something specific about computing, but I could not help but talk about that while answering your other questions. Your questions were thought provoking, and I have enjoyed this opportunity for reflection.

Dave, thank you for giving us this opportunity of sitting down and chatting with you. We really appreciate it.