ETH Institute of Geophysics: Center for Applied and Environmental Geophysics (CAEG)
SEG Distinguished Achievement Award 2015
Under the leadership of Dr. Alan Green during the period 1992–2012, the Applied and Environmental Geophysics Group at the ETH Institute of Geophysics significantly added to the field of near-surface geophysics. They pioneered developments in experimental design in electric resistance tomography, the use of land streamers, 3D GPR, and near-surface seismic reflection, seismic and EM modeling, joint inversion of multiple data sets, full-waveform inversion of GPR data, surface nuclear-magnetic resonance tomography, and the list goes on. In addition, their young researchers matured into leaders in multiple professions.
Citation for the SEG Distinguished Achievement Award
by Evert Slob
Alan Green initiated the Applied and Environmental Geophysics (AUG) group in 1994, shortly after his appointment to a new professorship at ETH-Zurich. The first AUG members, Klaus Holliger, Hansruedi Maurer, and Heinrich Horstmeyer, all young researchers at the time, helped establish the group’s research and teaching agenda for the following two decades. AUG’s achievements are suitably acknowledged by the following assertion of one of the nominators of the award: “There has been no more influential group in near-surface geophysics over the past 20 years.”
Multifaceted and multidisciplinary approaches have been key elements of the group’s successes in resolving numerous applied, engineering, and environmental issues. AUG has developed new data acquisition, processing, and interpretation schemes and novel theory and algorithms for various geophysical methods. As examples, it introduced or made pioneering contributions to experimental design in electric resistivity tomography (ERT), the seismic land streamer, seismic refraction tomography (SRT), 3D ground-penetrating radar (GPR), 3D engineering-scale seismic reflection techniques, semiautomated and multicomponent land- and air-based GPR data acquisition, surface nuclear-magnetic resonance (NMR) tomography, and time-lapse imaging.
It has written novel codes for the forward and inverse modeling of 2D and 3D ERT, SRT, GPR, NMR, electromagnetic (EM), and magnetic data acquired at the surface and within boreholes and tunnels. In addition to its traveltime and amplitude tomographic algorithms, the group has developed full-waveform tomographic codes for seismic and GPR data. Members of the group wrote the first programs for finite-difference seismic modeling and GPR migration that accounted for topography and made significant contributions to constrained and joint inversions of diverse types of data. Other notable contributions to data interpretation methodologies included the use of fractals in shallow geophysics, cluster analyses, attribute schemes for GPR data, and seismic and GPR guided-wave techniques.
AUG is well known for applying its innovative methods and other state-of-the-art techniques to a wide range of targets and issues, including archaeology, landfills, overdeepened river valleys, aquifers, unstable mountain slopes and associated microseismicity, rock glaciers, active faults, and radioactive-waste disposal. Group members are among the world leaders in rock glacier research and active fault imaging. They have resolved the structure and state of various rock glaciers using the ERT, SRT, GPR, and NMR methods. Their recent introduction of 3D helicopter GPR surveying for investigating topographically challenging terrains resulted in a novel thin-skin rock-glacier tectonic model.
Applications of their 2D and 3D GPR and engineering-scale seismic methods yielded detailed images of active faults in the United States and New Zealand. Shortly after the group demonstrated the existence of numerous potentially active faults buried beneath the Canterbury Plains, most of the region became seismically active, with one large earthquake destroying the business district of Christchurch. Based on the results of a large helicopter-mounted EM survey and complementary ground-based ERT, EM, and engineering-scale seismic surveying, they recently proposed a fundamentally new evolutionary model for the amazing Okavango Delta in southern Africa.
Important measures of AUG’s success are the awards and medals that its members have received and the quality of their careers. AUG members have won many best-paper awards and have received various prestigious medals. Former group members are active in an amazingly diverse range of positions in academia, industry, and government. Many are leaders of their professions (professors, CEOs, vice presidents, research directors). AUG passes on knowledge it has gained over the years to students in the highly popular Joint Masters Programme in Applied Geophysics run by ETH, TU Delft, and RWTH Aachen.
In conclusion, AUG has made numerous pioneering contributions in theoretical and experimental aspects of near-surface geophysics, across the full range of methods. It is most deserving of SEG’s Distinguished Achievement Award.