COSG Members


Committee Membership

THORSTEN W. BECKER, Chair, is the Shell Distinguished Chair in Geophysics at the Institute for Geophysics and the Department of Geological Sciences, Jackson School of Geosciences, at the University of Texas at Austin. His main research interests are in geodynamics and seismology with a focus on interactions between mantle convection and surface tectonics—studying the inner workings of terrestrial planets and how their mantle and surface systems have co-evolved over time. He combines field, laboratory, and numerical approaches into dynamical models, focusing on the physics of plate tectonics from grain-scale deformation to plate-scale flow. He was named an AGU Fellow in 2015 and served as Editor in Chief of AGU's journal G-Cubed for nearly a decade, among other service commitments. Dr. Becker holds an M.Sc. in physics from J. W. Goethe University, a Ph.D. in geophysics from Harvard University, and was a postdoctoral scholar at the Scripps Institution of Oceanography at the University of California, San Diego.

RICHARD M. ALLEN is director of the Berkeley Seismological Laboratory and professor in the Department of Earth and Planetary Science at the University of California, Berkeley. He is an expert in earthquake alerting systems – developing methodologies to detect earthquakes and issue warnings prior to shaking. His group uses seismic and GPS sensing networks and is experimenting with the use of smartphones. Testing of a warning system for the U.S. west coast is currently underway. Dr. Allen’s group also uses geophysical sensing networks to image the internal 3D structure of the Earth and constrain the driving forces responsible for earthquakes, volcanoes, and other deformation of the Earth’s surface. His research has been featured in Science, Nature, Scientific American, The New York Times, and dozens of other media outlets around the world. Dr. Allen has a B.A. from Cambridge University, a M.Sc. from the University of Durham, a Ph.D. from Princeton University, and was a Postdoctoral Fellow at the California Institute of Technology.

MARK D. BEHN is an associate professor in the Morrissey College of Arts and Sciences at Boston College. Dr. Behn’s research investigates the dynamics of Earth deformation in glacial, marine, and terrestrial environments through the use of a wide range of geophysical techniques. These techniques include the development of geodynamic models that relate laboratory-based rheologic and petrologic models to the large-scale behavior of the Earth, which are then applied to a spectrum of problems from basic science to societally-relevant issues. His research interests include dynamics of faulting, magmatism, and surface processes at mid-ocean ridges and continental rifts; seismic anisotropy and imaging of sub-asthenospheric mantle flow; evolution of the continental crust; and ice-sheet dynamics. He is the co-chair of the Geodynamics Focus Research Group for the Community Surface Dynamics Modeling System, was active in the MARGINS/GeoPRISMS program, and is a former fellow of the WHOI Deep Ocean Exploration Institute. Dr. Behn received his B.S. in geology from Bates College and a Ph.D. in marine geophysics from the Massachusetts Institute of Technology/WHOI Joint Program.

CYNTHIA (CINDY) EBINGER is a professor and Marshall-Heape Chair in the Department of Earth and Environmental Sciences at Tulane University. Her current research aims to understand the partitioning of strain between faulting and magmatic processes within continental and oceanic rift zones over time scales of hours to millennia and the longer-term evolution of continental rift zones from initiation to continental rupture. Her interest in continental rifts and plate boundary deformation began as an undergraduate at Duke University when she took part in a National Science Foundation-sponsored research project in the volcanically and seismically active East African rift zone. Dr. Ebinger served as a former president of the Tectonophysics Section of the American Geophysical Union (AGU) and was recently named an AGU Fellow for her "fundamental work on the evolution of continental rifts toward seafloor spreading in East Africa and afar." Dr. Ebinger earned her B.S. in geology from Duke University, S.M. from Massachusetts Institute of Technology (MIT), and Ph.D. in oceanography from the MIT/Woods Hole Oceanographic Institution (WHOI) Joint Program.

JEFFREY T. FREYMUELLER is the Thomas A. Vogel Endowed Chair for Geology of the Solid Earth in the Department of Earth and Environmental Sciences at Michigan State University. Dr. Freymueller is an internationally recognized leader in the field of geodesy and utilizes satellites from the Global Positioning System (GPS) to make highly precise measurements of movement on the Earth’s surface. In his far-reaching research activities, he has made discoveries in a wide range of topics including plate tectonics and plate boundary zones, faults dynamics, the continuing rebound of the Earth’s surface from the melting of ice-age glaciers, inflation and deflation of volcanoes, and interpreting how changing water and ice levels deform the Earth. He is particularly well-cited for his work on using GPS to understand the crustal deformation in China related to the formation of the Himalayas and the Tibetan Plateau. In addition to his research, Dr. Freymueller is the director of the EarthScope National Office. EarthScope is a long-term, large-scale program funded by the National Science Foundation to study the structure and evolution of North America and associated hazards through the deployment of thousands of geophysical instruments throughout the country. Dr. Freymueller also has served the scientific community as the U.S. National Correspondent to the International Association of Geodesy and its representative to the International Union of Geodesy and Geophysics, has served terms as an associate editor for the Journal of Geophysical Research and the Journal of Geodesy, and is currently Editor in Chief of the International Association of Geodesy Symposia Series. Dr. Freymueller received his M.S. and Ph.D. in geophysics from the University of South Carolina.

STEVEN (STEVE) JACOBSEN is a professor of Earth and planetary sciences at Northwestern University and a geophysicist specializing in rock and mineral physics. He studies the role of volatiles, especially water, in controlling geophysical processes driving the evolution of Earth’s crust, mantle, and atmosphere. He developed an ultrasonic technique for the diamond-anvil cell, which measures acoustic velocities in Earth and planetary materials at mantle conditions. By examining the influence of water on material properties and melt generation, Dr. Jacobsen is working to map mantle water content from dense regional seismic data such as the USArray. His research has broader implications for the global geochemical budget and origin of Earth’s water. Dr. Jacobsen is active in science and development at large-scale user facilities for high-pressure synchrotron research including the Advanced Photon Source at Argonne National Lab and the National Synchrotron Light Source-II at Brookhaven. His awards include a Presidential Early Career Award for Science and Engineering and a David and Lucile Packard Fellowship. He serves on the executive committee of the National Science Foundation’s Consortium for Materials Properties Research in Earth Sciences, and is associate editor of Geophysical Research Letters. He received his B.A. in geology and Ph.D. in geophysics from the University of Colorado at Boulder and was a postdoctoral fellow at the Geophysical Laboratory, Carnegie Institution for Science in Washington D.C.

MATTHEW PRITCHARD is a professor of geophysics at Cornell University. He is interested in how the Earth's surface deforms in response to earthquakes, magma movements, glacier dynamics, and human manipulation of subsurface fluids (e.g., carbon sequestration, hydrocarbon withdrawal). Dr. Pritchard uses a variety of tools including Interferometric Synthetic Aperture Radar (INSAR), GPS, and laser scanning to study deformation. He is a member of the American Geophysical Union, Geological Society of America, and the International Association for Volcanology and Chemistry of the Earth's Interior. He received the 2015 Geodesy Section Award from the AGU. He served on the UNAVCO Board of Directors from 2009 to 2012 and currently serves on the advisory board of the Carl Sagen Institute and the U.S. National Committee for Geodesy and Geophysics. He earned a B.S. in physics from the University of Chicago and an M.S. and Ph.D. in geophysics from the California Institute of Technology.

MAYA TOLSTOY is a professor in the Department of Earth and Environmental Sciences at Lamont-Doherty Earth Observatory (LDEO) of Columbia University in New York. For the Academic Year 2018-2019, Dr. Tolstoy will be the interim Executive Vice President and Dean of the Faculty of Arts and Sciences at Columbia University. She is a marine geophysicist specializing in seafloor earthquakes and volcanoes. She has worked extensively on the structure and seismicity associated with mid-ocean ridges and, in particular, how earthquakes in this environment can be used to illuminate hydrothermal and magmatic processes. In addition, she has done research on hydroacoustic signals and anthropogenic noise in the ocean. Dr. Tolstoy has extensive seagoing experience, having participated in 31 seagoing expeditions; on 18 of those she was chief or co-chief scientist. She currently helps oversee the LDEO Ocean Bottom Seismograph Instrument Pool (OBSIP), and serves on the Incorporated Research Institutions for Seismology’s OBSIP management council. In 2009, she was one of 47 finalists for NASA’s astronaut selection and is the recipient of the 2009 Wings Worldquest Sea Award honoring women in exploration. Dr. Tolstoy has also done extensive outreach work to communicate the excitement and importance of earth science to non-science audiences. She holds a B.Sc. Honors in geophysics from the University of Edinburgh and a Ph.D. in Earth science from Scripps Institution of Oceanography, University of California, San Diego.

WILLIAM (BILL) R. WALTER is a research geophysicist at the Lawrence Livermore National Laboratory where he leads the Geophysical Monitoring Programs. He is also the Chief Scientist for the DOE/NNSA Office of Defense Nuclear Nonproliferation sponsored Source Physics Experiments. His research areas include geophysics and seismology, seismic source physics, Earth structure, tectonics, treaty verification, and related policy issues. He served on the Seismic Subcommittee for the National Academies of Sciences panel that issued a 2012 report updating the technical issues related to the Comprehensive Nuclear-Test-Ban Treaty. He is the author or co-author of more than 75 peer-reviewed scientific papers. Dr. Walter received a B.A. in physics from Middlebury College, a M.S. in physics from the University of California, San Diego, and a Ph.D. in geophysics from the University of Nevada, Reno.