“Geophysics is a hugely rewarding profession”

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

I grew up in the city of Novosibirsk in Siberia, more precisely in Akademgorodok, a region of Novosibirsk, which has one of the largest concentrations of scientists in the world. Growing up in Akademgorodok meant that there was no choice about going into science, the only choice was what particular science to pursue. My choice was set when I met Sergey Goldin, a famous and charismatic Novosibirk geophysicist. Goldin convinced me that exploration geophysics was the most exciting subject of all. Later on, he became my first scientific advisor.

How did you decide to come to Stanford?

I was attracted by Jon Claerbout and the work of the Stanford Exploration Project. Sergey Goldin was a friend of Claerbout’s and spent several months at Stanford in 1989. At one time, around 1993, he received a chapter from the book that Jon was writing and showed it to me. I wrote a letter with some comments to Jon and in return received an e-mail from him (the first e-mail I had ever received!) with an invitation to apply to Stanford.

Since you came to the US to pursue higher studies in 1994, you have essentially stayed there. Could you tell us how you decided on that?

I love the US as a country and its defense of personal freedom, but I did not have a clear intention to stay there initially. At Stanford, I tried to learn as much as possible to prepare for the case that I would go back to Russia to teach Russian students. In 1998, I spent six months at an internship in England (at Schlumberger Geco-Prakla) to experience the life in the UK and Europe. It was a good experience, but the pull of the US was too strong.

Who have been some of your mentors?

I was very lucky with mentors, both the official advisors (Sergey Goldin, Jon Claerbout, and James Sethian), and many other excellent scientists whom I met in Novosibirsk, Stanford, and Berkeley. When I came to Texas, I worked with Bob Hardage, who is a true gentleman.

You have received many awards for your work. 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 a firm grounding in mathematical concepts has kept you in good stead, or is it something else?

I am proud of my awards but it is important not to attach too much meaning to them. Many excellent professionals never receive any awards, because there are random factors at play in the selection process. It is not a reliable measure of one’s worth as a professional.

You did not answer the other parts of my question.

I believe that, in science, as in sports, success comes partially from natural abilities but mostly from dedication, hard work, good coaches, and being in the right place at the right time.

Your presentations at the SEG Convention have usually been in the top 30 or have received awards in the last few years. 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, is it something new you present each time, or something else?

This is again partially random. Nevertheless, I take the art of presenting scientific information seriously, because it concerns not only SEG presentations but also teaching in the classroom. With my SEG posters, I receive a lot of help from the superb media department at BEG and its graphics designers (John Ames and Joel Lardon in particular). They invent interesting ways to present computational results graphically.

Tell me about Sergey, the person – your habits, your likes/dislikes, etc.

I don’t know where to start. I like the process of learning (understanding how things work), especially when it involves collaboration with other people. I read a lot of literature, including scientific papers from applied mathematics and other fields.

Sometimes you find inspiration in strange places. But nothing replaces a direct human contact.

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

Do you mean Geophysics the journal?

No, not the journal, the discipline.

One of the recent contributions is the concept of local seismic attributes. They are smooth measures of local properties defined with the help of regularized least-squares inversion. The local slope is a particularly powerful attribute, because it captures the geometry of seismic data or seismic images. Local slope finds applications in both seismic imaging and seismic interpretation. A surprising fact is that, if you measure local slopes in prestack data in both source and receiver directions, you don’t need velocity analysis or any other measurements to perform prestack time migration. Intuitively, this has been understood for a long time, but only now we can formulate the mathematics of this transformation precisely. My students and I keep discovering new attributes and new applications for them. This year, Guochang Liu, a visiting student from China, came up with a very interesting idea of a robust time-frequency decomposition using local attributes.

So what areas of geophysics do you like better than others? Do you plan to focus research on these areas or would you like to be all over the place?

Computational and mathematical skills apply to different areas. Seismic imaging is always fascinating and attracts exceptionally smart people. Recently, I started to attend seismic interpretation sessions at SEG and find that area very interesting and important as well.

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

Scientific work usually consists of a lot of frustration and a few breakthrough moments. The “aha” moments, when you come up with unusual ideas for solving problems, are the most fun but they usually come after long periods of frustration. I treasure those moments the most.

Could you say something about them?

Local attributes are conveniently defined with the help of “shaping regularization”. The idea of shaping is fairly simple but it took many years of frustrating experiences with the conventional regularization methods before I suddenly had a hunch to try something different.

I was also lucky to witness some “aha” moments with other people, for example when Jon Claerbout first came up with the idea of helix filtering.

Please say something about helix filtering, as many of our readers may not be familiar with this term.

At the time, I was playing with the idea of using recursive filters for model reparameterization but did not know to extend it from 1-D to multiple dimensions. One morning, Jon stormed into my office. He took his bicycle helmet off. Under the helmet was a small woolen hat knitted by his son. Jon pointed to the helical pattern on the hat and said, “Here is how you do it!” Claerbout’s helix idea enables recursive filtering in two or more dimensions by arranging all samples on the grid into a one-dimensional sequence. It inspired a lot of follow-up research at Stanford, including, for example, James Rickett’s work on what became known as “seismic interferometry”.

What are your aspirations for the future?

I have invested several years of work into the “Madagascar” software project. “Madagascar” (freely available at http://www.ahay.org/) is primarily a tool for computational research but it is also a platform for collaboration. More than 15 people have been contributing to its development. The entrance is wide open: Anyone can become a developer and share the responsibility for extending and improving the package, in the tradition of free open-source software, such as Linux or Firefox. “Madagascar” implements Jon Claerbout’s idea of “reproducible research”: every documented computational experiment can be verified and extended by others. My biggest aspiration is to see this project and the community around it grow, because I think that our collaboration tools will enable unprecedented research progress.

People have a certain level of expectation from ‘star’ players. When they don’t come up to that level the fans are disappointed. Going by that analogy, for a researcher/group who has contributed very effectively to the way we use seismic data, the level of expectation from him or the group is high. When the contributions from him or the group drop off, do you think the geophysical community is disappointed? I would like to hear your take on this.

Yes, I suppose there might be some of that. I like to compare exploration geophysics to Hollywood. The movie industry mixes art and business. We mix science and business. The business component boosts creativity but it can also be dangerous. In any case, there are definitely some “stars”, and people expect certain performance from them. I believe that a true scientific research should be driven by the desire to understand something, not the desire to show off.

You have a position of associate professor of geophysics at University of Texas. Please tell us about the type of work that is being done in your group and how many people are engaged in doing that.

I joined the faculty two years ago. It is a joint appointment: 2/3 of my time is spent at BEG doing research, and the rest is teaching. I work with several Ph.D. students and postdocs. We work on individual projects with the industry rather than in a consortium. There have been 15 or so different projects with different companies in the last five years. I think this is a good way to focus on research topics that are both important and challenging.

Could you also say how many people are working with you, roughly?

There are currently three postdocs and five Ph.D. students. As for other colleagues, I have been trying to team up with other geophysicists in Austin as well as with geologists and applied mathematicians.

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

BEG has some fantastic people. The most attractive aspect for me is the team culture. All research is organized by teams, which are often multidisciplinary (geophysicists, geologists, reservoir engineers), as opposed to individual professors that you find in typical academic departments. I believe that the most challenging research problems can be solved only by a multidisciplinary effort. The need to communicate with scientists from other disciplines is also a great driver for professional growth, because it makes you continuously learn new things.

In 2001 you received the SEG J. Clarence Karcher Award for ‘numerous contributions to geophysics’. For the benefit of our members, please tell us what those contributions are.

think the committee simply could not identify any particular contribution that would be worth an award.

Our readers would like to know about some of the work that you have done and which was considered unique for an award. Could you please elaborate here?

My Ph.D. thesis was on 3-D seismic data regularization. It used an early version of the local slope attribute to predict structural patterns in the data as well as differential offset continuation to predict physical connections that exist between different parts of prestack data.

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

You probably know more about it than I do. When it comes to revolutionary new technologies, I prefer to be a conservative.

This is good beginning to your answer, but I would like you to say something from your perspective.

In computational fields, such as seismic data analysis algorithms, our technological progress is much slower than it could have been, because we don’t have good standards for sharing research results. That is why I invest a lot of effort in reproducible research. Once we are able to share results in a meaningful way, the progress should become much faster.

What type of problems are you working on?

I think of them as geophysical problems that can be solved by mathematical or computational methods.

In a general way, please mention a couple of ideas you are working on.

One example is the idea of diffraction imaging (separating and imaging of seismic diffractions), which came out of a joint work with Evgeny Landa and Tury Taner. It enables a novel way of detecting fractures, which is important in exploration for tight gas and other unconventional reservoirs.

I would like to know your perception about writing; I see you have many papers published in geophysics and many are still submitted and accepted. How do you do all this in your 24 hours every day?

Writing does not come easy to me. I agonize and procrastinate. Some of the recently published papers have been on my desk for five years or more. If you are an academic and publish papers for a living, it is important to form a habit of publishing so that once in a while you can stop doing the fun stuff (getting new results) and wrap something up for publication.

What are your other interests?

Nothing unusual. Books, movies, hiking... I did cross-country skiing many years ago, but there is not much opportunity for that in Texas. I also used to write humorous poetry (in Russian) but, after that hobby helped me find my wife, it gradually went away.

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

First of all, they are making a right choice. Geophysics is a hugely rewarding profession and has been attracting excellent people with all kinds of backgrounds. If you want to be a research scientist, it is important to cultivate curiosity and courage, two qualities that will allow you to go to places where nobody else went before. Communication skills are also very important, especially for foreign students.

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

It looks like we touched on everything. Let me say a few more words about the culture of reproducible research, because it may affect many of your readers.

Please do so.

When you publish new theoretical results, say, a new equation, you are supposed to provide the complete mathematical derivation. Otherwise, the journal reviewers and editors will not accept the paper but, most importantly, the readers will not be able to verify and extend your results. When you publish the result of a physical experiment, you are also supposed to provide a complete description of the experiment setup to allow other labs to reproduce it. The same is not true for computational experiments: most computational results get published today without providing sufficient means for the reader to reproduce and verify them. This is simply because the computational science is young and has not developed good scientific standards yet. The situation is changing.

People from different disciplines (computational statistics, biology, chemistry, astronomy, etc.) are starting to realize that the current practice is unacceptable and are starting to demand new standards. Geophysics is ahead of some of the other sciences thanks to the pioneering work of Jon Claerbout. This year could become a tipping point: several publications on reproducible research appeared simultaneously in different journals, and a special roundtable was organized last month at the Yale Law School to come up with a joint manifest statement. The “Madagascar” package provides tools for organizing computational experiments and integrating them with publications. You can use them for external publications as well as internally inside a company or a research lab to share results or to transfer technology from research to production. At the end of the day, reproducibility is what separates science from superstition.

Sergey, thank you very much for giving us this opportunity to engage you in a chat. I have enjoyed it.

Thank you!