Electromagnetics

sensitivity DC

Our main activities concern the theory and application of electromagnetic methods in applied geophysics. Electromagnetic fields provide significant information on the structure of the Earth's interior covering scale lengths from a few centimeters to tens of kilometers. The fields' physical behavior is governed by a wide range of forms and reaches from quasi-static over diffusive to wave-like characters. We develop numerical simulation and inversion software for the following marine, airborne or land-based methods:

  • DC Resistivity and Induced Polarization
  • Transient Electromagnetics
  • Magnetotellurics and VLF/VLF-R
  • Controlled Source Electromagnetics
  • High-Frequency Electromagnetics and Ground Penetrating Radar
  • Magnetics (Gravity)
 

Our numerical methods are based on finite difference and finite element techniques. The latter are formulated on unstructured tetrahedral grids and are able to incorporate arbitrary geometry and topography. The inversion strategies imply Newton, Quasi-Newton, Gauss-Newton and all-at-once approaches. We have also gained experience with stochastical approaches such as Simulated Annealing, Genetic Algorithms and Neural Networks.

Using our techniques we address a wide variety of practical problems and fields of application:

  • Mineral exploration
  • Geothermal energy
  • Hydrocarbon exploration and gas hydrates
  • Groundwater
  • Volcanoes
  • Archaeology
  • Soil remediation and environmental problems
  • Terrestrial planets
  • Tree root zones and eco-systems