The UBC Geophysical Inversion Facility carries out research on geophysical inverse theory, modelling, and applications.

• Virgin River Geophysical Case Study: The 2010 Virgin River complex geophysical data interpretation project has been completed in collaboration with Cameco Corporation. The area under study is known to host a deep-seated Uranium deposit. Multiple geophysical data sets have been analyzed and inverted in 3D implementing the newest UBC-GIF codes, including multi-transmitter time domain inversion (h3DTDInv) and ZTEM 3D Inversion code (MTZ3DInv). The data sets analyzed in this study include airborne Total Field Magnetic data, airborne Gravity data, airborne Time Domain EM data (Megatem), airborne passive source EM data (ZTEM), ground loop EM data and ground DC resistivity data. In this research the inversion results were verified using the known drill hole data and presented at BCGS meeting in Vancouver (October 2010).

• Multi Source Inversion of TEM Data (MITEM): Geophysical surveys often employ many sources and forward modelling that uses are iterative methods can be become impractical. This can be overcome by using direct solvers for Maxwell's equations. In this research we develop the inversion procedure as well as appropriate workflows for inverting field time domain EM data. 2008 SEG abstract

• Inversion of TEM data for highly conductive targets: Highly conducting targets buried in a resistive medium pose challenges in working with finite volume solutions for Maxwell's equations. This research is intended to further develop our software and strategies for these problems.
  2008 SEG abstract

• Enhanced geophysical inversion: The quality of inversion images is enhanced when additional geologic and geophysical information is incorporated into the inversion. Achievement of these goals requires additional functionality in the inversion codes as well as software utilities that link geologic and physical property information to our inversion codes. 2008 SEG abstract

• Magnetotellurics: The electrical condcutivity of the earth can be probed by using natural source fields. Previous research on MT is being expanded to generate more efficient inversions and also invert Z-TEM data from newly developed surveys for mineral and oil exploration. 2008 SEG abstract

• Survey design: The ablility to invert individual data types opens the scope for survey design. How should data be acquired to answer a particular environmental, exploration, or geotechnical question?

• Remanent and high susceptibility magnetics: When the magnetic permeability is high then the full non-linear equations must be solved to account for self-demagnetization. When the rocks are remanently magnetized then this must be modelled in the inversion. We are approaching this latter problem solving for the total magnetization.

• Complex physical properties: Electrical conductivity and magnetic susceptiblity can be frequency dependent. In mineral exploration, IP (Induced Polarization) is diagnostic of many types of mineralization. In UXO and mineral work, the effects of super-paramagnetization can mask the desired signals. Our research is focussed upon developing forward modelling and inversion techniques to work with these data in frequency and time domain EM surveys. 2008 SEG abstract

• MMR/MMIP: Because of renewed interest in these data sets we plan to build upon previous research to make codes more efficient and apply them to exploration problems. 2006 MMIP paper, 2002 MMR paper .

• Application research: A GIF goal is to enhance the use of geophysics in applications to exploration, environmental and geotechnical problems. New types of data, new geologies, or new exploration questions are often the catalyst for new research.

• Improving EM forward modelling and inversion: Numerical techniques such as employing Octree or other unstructured grids, using direct decomposition of forward modelling matrices, generating approximate inversions of the data to provide starting models, etc can greatly improve computational efficiency.