Difference between revisions of "Mrinal Sen"
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Revision as of 08:48, 5 December 2018
Mrinal K. Sen received the Virgil Kauffman Gold Medal in 2018 and SEG Honorary Membership in 2015. He pioneered development and application of stochastic optimization methods for seismic waveform inversion, gravity interpretations, and seismic migration velocity analysis. In addition to serving as a University of Texas professor, Mrinal also served as the director of the National Geophysical Research Institute of India.
Mrinal Sen has made significant contributions in applied seismology on elastic anisotropic wave propagation, computational seismology, full-waveform inversion, inversion of seismic data for fracture analysis, fluid content, rock properties and improved resolution, reservoir characterization, and CO2 sequestration. Sen's work on these topics continues to be on the leading edge of seismic technology. With more than 3300 citations, his work is followed and recognized by many over a wide spectrum of contributions. While his most-cited papers are his earliest, within the last five years he has authored or coauthored two widely cited books and 170 papers. His most current contributions represent ventures in new areas of mathematics. In addition to Sen's research achievements, he has an outstanding record as an educator. A countless number of his former students permeate the industry and are making their own contributions. He has taught and continues to teach short courses throughout the industry and at SEG meetings. As an active professor, he continues to mentor a full complement of students currently under his guidance and he shows no sign of letting up.
Virgil Kauffman Gold Medal
It is our great pleasure to introduce Mrinal Sen, professor and Jackson Chair of the Institute for Geophysics at the University of Texas at Austin, as the Virgil Kauffman Gold Medal winner. The medal recognizes his pioneering work on geophysical inverse problems and applied seismology.
Inferring the earth's subsurface physical properties from surface observations is known as inversion and is fundamental to all geophysics. Geophysical inversion has been intensely studied for generations and continues to be one the most active research topics. The reason this research topic continues to be current is that inversion is mathematically ill posed. This means the mathematics involved in inversion does not readily allow for unique and stable numerical solutions. Mrinal's state-of-the-art work in applying global optimization to seismic inversion addresses these numerical problems. Global optimization is computationally intensive, and Mrinal has developed hybrid techniques making inverse solutions accurate and numerically feasible.
Mrinal has made other significant contributions in applied seismology. He has a wide range of research interests and has published key papers on elastic anisotropic wave propagation, innovative algorithms in computational seismology, and reservoir characterization. His diverse range of expertise has impacted many areas of exploration geophysics. In inversion, Mrinal, his collaborators, and his students have developed practical and computationally efficient algorithms by creating robust hybrid algorithms. Given the immense volume of today's data, global optimization applied to exploration seismic inversion is computationally intractable even with today's computing hardware and software. Mrinal's hybrid solutions make this new technology accessible. With the recent attention of full-waveform inversion (FWI), these developments are increasing in importance. FWI is also computationally expensive, and Mrinal's work on efficient forward wave-propagation models addresses this issue. In addition, extending forward modeling to anisotropic media provides a more complete and realistic representation of seismic wave propagation in the earth, and Mrinal has made significant contributions in this area. Over many years, Mrinal's work on these topics continues to be on the leading edge of seismic technology.
Mrinal develops theories based on ideas developed in other fields, i.e., mathematics, physics, statistics, computational and biological sciences, and applies these developments to define a pragmatic framework for seismic inversion and other topics. He has unique insight into how complex mathematical theories can translate into useful practical algorithms.
The Virgil Kauffman Gold Medal is for a person who has made an outstanding contribution to the advancement of the science of geophysical exploration as manifested during the previous five years. Some of Mrinal's main contributions during this time period include Global Optimization in Geophysical Inversion, published in 2013. This book describes an up-to-date overview of recent global optimization techniques used in geophysical inversion. The theoretical basis is discussed as well as practical approaches for algorithm development. There are several different algorithms, and this book provides insight into which one would best fit specific applications. For example, the book contains a comparison of finite difference and spectral element methods for elastic wave propagation in media with a solid-fluid interface. This publication compares two of the most commonly used numerical approximations for the elastic wave equation. The solution for the solid-fluid interface is a benchmark test and is useful for assessing the accuracy of numerical solutions. This work provides insight into the strengths and weaknesses of specific numerical approximations. Also, Mrinal has a key publication that shows how global inversion can provide viable initial models used in the FWI iteration process. This solution addresses a primary limitation of FWI methodology. The initial model is key for the overall FWI process to converge to a meaningful solution.
In addition to Mrinal's research achievements, he has an outstanding record as an educator. He has spent most of his career with the Institute for Geophysics at the University of Texas at Austin. He began as a research associate (1989) and rose to the positions of research professor at the institute (2004), professor in the Department of Geological Sciences (2004), and the John A. and Katherine G. Jackson Chair in applied seismology (2009) at the Jackson School of Geosciences. While on leave from the University of Texas, Mrinal was director of the National Geophysical Research Institute in Hyderabad, India (2012–2014). A countless number of his former students permeate the industry and are making their own contributions. He has taught and continues to teach short courses throughout the industry; one is on FWI, which he teaches at SEG meetings. As an active professor, he still has a full complement of students currently under his guidance and he shows no sign of letting up.
Mrinal has dedicated himself to geophysical education, research, and development for more than 30 years. He has always been active, enthusiastic, and visionary. He has the reputation of one of the most distinguished geophysical innovators and is well recognized in our community. In 2015, he was awarded an SEG Honorary Membership for his contributions to the Society. The Virgil Kauffman Gold Medal is fully deserved and sets an exemplary model of high-quality education and research in SEG.
Biography Citation for the SEG Honorary Membership Award 2015
by Paul Stoffa
Mrinal Sen received his B.Sc. and M.Sc. degrees from the Indian School Mines and Ph.D. from the Hawaii Institute of Geophysics of the University of Hawaii. Prior to joining graduate school, he worked in the oil industry as a seismic data processing geophysicist. His graduate research, supervised by Neil Frazer, showed him to be an excellent and high-caliber scientist. Mrinal’s original work on a multifold-path integral formulation for computing seismograms was a new and unique approach to elastic seismogram synthesis. He investigated seismic modeling in anisotropic media when anisotropy was not commonly employed in seismic analysis. Later in his career, he followed up this early research by formulating plane-wave analysis methods for imaging anisotropic seismic data.
After graduation, Mrinal worked to develop numerical models for seismic hazard estimation in the Los Angeles Basin. Thus, his original research interests were very broad; he studied seismic wave-propagation problems at all scales ranging from global to exploration seismology. This trend continued throughout his research career, in which he addressed a large number of significant and varied problems but now principally focused on the field of exploration geophysics.
Mrinal joined the University of Texas at Austin Institute for Geophysics in 1989 as a researcher and later became a professor in the Department of Geological Sciences and holder of the John A. and Katherine G. Jackson Chair in Applied Seismology in the Jackson School of Geosciences. Mrinal is a passionate teacher in and outside the classroom. To date, he has supervised or cosupervised more than 25 graduate students and an equal number of postdoctoral fellows and visiting scientists. He has been an associate editor of Geophysics and teaches an SEG continuing education short course on full-waveform inversion.
Mrinal’s long-term collaboration with Paul Stoffa resulted in the most cited papers on global optimization methods published in Geophysics. Their book on global optimization methods in geophysical inversion continues to be one of the most cited resources on this subject. This book received attention not only from the geosciences community but from other branches of science and engineering as well. In 2006, Mrinal published a monograph on seismic inversion for the Society of Petroleum Engineers.
In addition to continuing his work on inverse problems and uncertainty quantification using stochastic methods, Mrinal works on numerical and analytical methods for seismogram synthesis. His most recent research with former student Jonas DeBasabe on error analysis is the first to systematically document numerical dispersion errors for finite-element and finite-difference methods in a generalized framework, and collaborations with Yang Liu resulted in new methods for FD discretization and absorbing boundaries.
During 2012 and 2013, Mrinal worked as the director of the National Geophysical Research Institute (NGRI) in India, a position to which he was appointed by the prime minister of India. During his tenure at NGRI, he combined his strong technical skills with his management acumen to develop strong research and academic programs. He led a vigorous program of airborne EM surveys for groundwater exploration and uranium exploration, developed strong ties with the oil industry, built a high-performance computation center, and established a robust academic program in geophysics.
Mrinal Sen highly deserves the recognition of Honorary Member by the Society of Exploration Geophysics for his many excellent research contributions in seismic wave propagation, inverse problems, imaging, and reservoir characterization. In addition, he has mentored a large number of geophysics graduate students and postdoctoral fellows who have joined the exploration industry and contributed to its success. Mrinal is also recognized for his relentless services to the geophysics community in general and the Society of Exploration Geophysics in particular.
Mrinal K. Sen received a B.S. and an M.S. in applied geophysics from the Indian School of Mines and a Ph.D. in geophysics from the University of Hawaii at Manoa . He worked as an exploration geophysicist before becoming a researcher in 1989 at the Institute for Geophysics, University of Texas at Austin, where he is a professor and holder of the Jackson Chair in Applied Seismology at the Jackson School of Geosciences . His research interests include seismic-wave propagation, inverse problems, seismic imaging, and computational geophysics. He has written two books on global optimization and seismic inversion. He is a member of SEG, AGU, EAGE, SIAM, and EAS.
- (2018). ”Honors and Awards.” The Leading Edge, 37(11), 842–854. http://dx.doi.org/10.1190/tle37110842.1
- Contributors, Geophysics, 74, no. 4, Z69-Z73.
- Jackson School of Geoscience, University of Texas at Austin: Faculty