# Robert Clapp

**Robert G. Clapp** is receiving the J. Clarence Karcher Award
in recognition for his numerous and significant contributions
to seismic imaging and processing. Bob has authored
or coauthored six papers in scientific journals (GEOPHYSICS and
Geophysical Prospecting) and 23 expanded abstracts for pre-
sentations at SEG and EAGE meetings. One of Bob?s most important
contributions is his pioneering work in combining regularization
with preconditioning in geophysical inverse problems.
Preconditioning is not new, but Bob unified the properties of regularization
with the convergence properties of preconditioning.

Bob's Ph.D. dissertation introduced important new methods for constraining velocity estimation by using geologic knowledge. He was one of the first to develop the concepts of and to perform velocity analysis for 3D prestack depth migration using tomography and wave-equation techniques. His ideas on velocity estimation are now routinely applied in many large-scale projects around the world. Bob has the rare capability of mastering the geophysical, mathematical, and computational components of seismic imaging and is able to turn complex ideas into efficient computer algorithms.

## Biography Citation for the J. Clarence Karcher Award

*Contributed by Jon Claerbout*

Robert G. (Bob) Clapp grew up in Eugene, Oregon, got
his B.Sc. at Colorado School of Mines, and his Ph.D. at
Stanford University where he is now a senior research engineer.

His interests in his youth were math and history until
his first real exposure to physical sciences in high school.
He received his B.Sc. from CSM in only three years. He
intended to enter Mines in physics but, through a happy
mistake, he was entered in geophysics. When he took a
course by Ken Larner, he got hooked on geophysics. He came
to Stanford University in 1993 and got his Ph.D. in 2001 with
a thesis *Geologically Constrained Migration Velocity Analysis.*

During this time he found his bride, the former Marie Prucha, also a geophysics graduate of the School of Mines (and now also a Ph.D. from Stanford), and they now have two beautiful daughters, Sammy and Sydney.

During Bob?s time at Stanford, 1993 to the present, he has gained a reputation as a hyperactive juggler---able to keep a huge number of ideas and projects in the air. Between his own research, his collaboration with Stanford students and with people from other universities, and his consulting work with various companies, Bob has managed to author and coauthor 89 report papers. These 89 papers cover a wide variety of topics:

- (1) migration velocity analysis,
- (2) nonstationary filtering in multiple dimensions,
- (3) data regularization,
- (4) data alignment,
- (5) signal-to-noise separation,
- (6) velocity uncertainty,
- (7) geostatistics done with operators,
- (8) hardware acceleration for imaging,
- (9) automatic parallelizing of embarrassingly parallel applications,
- (10) converted-wave processing, and
- (11) automatic interpretation.

It's no surprise that when anyone has a problem at SEP the solution often turns out to be 'ask Bob'; so, beyond those 89 papers that he has authored and coauthored, he has made substantial contributions to the papers of many other people.

In most cases, Bob brings a critical skill to the project. After Sergey Fomel, Bob is the most significant contributor to my current book project. He has also shared teaching my 2D reflection seismology class.

In addition to geophysics, Bob is an expert on high-performance
computing. This is an invaluable skill because
some years ago an SEP sponsor offered us this advice:
*Please solve no more 2D problems in a newer and better way. Please solve 3D problems, no matter how rudimentary your approach.* It is a real struggle for academics anywhere
to deal with the weight and complexity of handling 3D seismic
field data. The fact that all graduate students at SEP now
get real hands-on experience with 3D field data (a requirement
for a thesis) is wholly a credit to Bob Clapp and Biondo Biondi.
Bob handles both the hardware and the software necessary
for the graduate students at SEP and has recently
taken over responsibilities in managing the Stanford School
of Earth Science?s pooled cluster computers. He is also teaching
a new class, Introduction to Computational Earth Sciences.