The BCGS is proud to announce its EM Workshop 2015 that will be held at the BCIT Downtown Campus on Friday October 16th. The executive has been hard at work gathering an amazing panel of EM inversion experts who will discuss the latest advances in EM geophysics.
We are putting a slightly different twist on the workshop concept this year as it is going to be an e-poster type, day-long session, where our different experts will be presenting the best of their practical results, rather than a more formal presentation format. The day will start with our opening keynote speaker, Richard Smith, who will give an overview of all the different EM inversion procedures. Then attendees will be divided in small groups and will rotate through the presentations throughout the day. The small size of the groups is aimed at fostering discussion with our speakers and emphasizing the audience participation. At the end of the e-poster session our closing keynote speaker, Alan Jones, will wrap up the day by reviewing what was presented to the audience and what was learned during the day. Everybody will be then invited to join our speakers and the BCGS executive for a social event in a nearby location.
You can find below more details about the event, our sponsors and our speakers.Hope to see you all in October!
Regards,
The BCGS Executive
Workshop Details
| Opening Speaker: | Richard Smith | Laurentian University |
| Speakers: | Dima Amine | Geosoft Inc. |
| Lief Cox | TechnoImaging LLC | |
| Colin Farquharson | Memorial University of Newfoundland | |
| Peter Fullagar | FGCL Consulting Ltd. | |
| Eldad Haber | University of British Columbia | |
| Michal Kolaj | Laurentian University | |
| Doug Oldenburg | University of British Columbia | |
| Bill Petrick | Industrial Imaging Co., Inc. | |
| Phil Wannamaker | University of Utah | |
| Closing Speaker: | Alan Jones | Dublin Institute of Advanced Studies |
Date: Friday, October 16, 2015
Time: 8:00 am PST – 4:45 pm PST
Location: BCIT Downtown Campus (555 Seymour St. Vancouver, BC, V6B 3H6, Canada
Admission Cost: Regular $120 / Student $60
Sponsors
If you would like to sponsor our event, please contact us at info@bcgsonline.org
Speaker Bios
| Richard Smith: Laurentian University
Website: http://des.laurentian.ca/people/faculty/richard-s-smith Title: Electromagnetic inversion: challenges and approaches to solutions Outline: The presentation will discuss some of the challenge of EM inversion: 1) too little data, 2) too many unknowns, 3) no linear solutions, how to select an initial guess, 4) how to discretize the earth and how to select a solution from the many possible solutions. The presentation will discuss the different approaches that people have been taken to the EM inversion problem and how each approach is designed in some way to deal with some of the issues.
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| Dima Amine, Geosoft Inc.
Website: http://www.geosoft.com/voxi Title: A Comparison of Quasi-3D Inversions of Frequency Domain EM Data Outline: Full 3D EM inversion requires calculation of the 3D induced current in the earth whereas the Quasi-3D approximations are based on a full 3D inversion but with a simplified, approximate, induced current flow in the earth. We demonstrate two Quasi-3D approximations by comparing their response over the interface of a quarter-space model with the full AEM response, and then demonstrate the methods on a challenging synthetic model and on field data.
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| Leif Cox, TechnoImaging LLC
Website: www.technoimaging.com Title: Practical aspects of large-scale inversion Outline: Large-scale inversion requires a somewhat different approaches than deposit scale inversion. Either computation or physics-based compression must be used to enable practical run times. Data need to be carefully and often adaptively weighted to ensure uniform fit across all inversion regions. Model weights should be applied to give uniform importance to each model parameter, both to account for sensitivity variations with depth and variations across different parameters such as conductivity and chargeability. We describe how to make intelligent choices for these and other parameters of inversion. Case studies represent challenges and solutions in large-scale inversions of the airborne EM data.
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| Colin Farquharson, Memorial University of Newfoundland
Website: http://www.esd.mun.ca/~farq/ Title: Towards Real Earth Models — Computational Geophysics on Unstructured Tetrahedral Meshes? Outline: When visualizing and modelling the subsurface in the context of mineral exploration, geologists use 3D Earth models that are made up of tessellated wireframe surfaces. In contrast, we geophysicists have so far used almost exclusively rectilinear meshes to parameterize our Earth models. Wouldn’t it be better if our geophysical models were parameterized in a way that was consistent with – meshed seamlessly with – geological models? An Earth model could then be a single unified, integrated entity that served as both a geological model and a geophysical model. I shall present some examples of the work we’ve been doing to try to achieve this goal and some of the challenges that we face.
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| Peter Fullagar, FGCL Consulting Ltd.
Website: www.fullagargeophysics.com Title: Fast 3D inversion of transient electromagnetic (TEM) resistive limit data Outline: A fast 3D inversion scheme has been developed for time-integrated (resistive limit) TEM data. The resistive limit inversion is up to 100 times faster than “rigorous” 3D TEM inversion. The software can advance integrated interpretation by performing inversion on a geological model. The inversion scheme is illustrated via application to airborne, ground, and downhole TEM data.
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| Eldad Haber: University of British Columbia
Website: www.math.ubc.ca/~haber Title: 3D inversion of airborne data Outline: In this talk we will show how common airborne data sets can be inverted in 3D in order to give geologically meaningful information, We use both synthetic and field examples
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| Michal Kolaj, Laurentian University Website: http://des.laurentian.ca/people/phd-studentsTitle: Inductive electromagnetic data interpretation using a three-dimensional distribution of three-dimensional magnetic or electric dipolesAuthors: Michal Kolaj1 and Richard Smith1 1Laurentian University, Department of Earth Sciences, Sudbury, Ontario, Canada Outline: We invert inductive magnetic field data, at a given fixed-time or frequency, for the causative subsurface current system which we represent with a 3D distribution of 3D magnetic (closed loop current) or electric (line current) dipoles. The methodology is tested on synthetic plate data and two field examples; a deep massive sulfide (mineral exploration target) and a near-surface mine tailings pond (engineering/environmental study).
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| Doug Oldenburg: University of British Columbia
Website: www.gif.eos.ubc.ca Title: Can airborne IP be valuable for kimberlite exploration? Authors: Douglas W. Oldenburg1 and Seogi Kang1 Outline: Recent developments in airborne TEM inversion to recover 3D IP structures are applied to Tli Kwi Cho (TKC). We present the basic procedure by which time channels, that have significant IP response, are first subjected to an EM decoupling procedure and then inverted to recover a 3D pseudo-chargeability at each time. A subsequent inversion carried out for each volumetric cell recovers estimates of Cole-Cole parameters for that cell. For TKC the recovered decay times for the three rock units PK, HK, XVK, are distinctly different. Laboratory analysis of core samples supports this conclusion.
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| Bill Petrick, Industrial Imaging Co., Inc.
Website: www.industrialimaging.com Title: Pitfalls in 2D AMT Inversion Outline: AMT is a powerful tool for minerals and water exploration. It is common practice to throw a few AMT (or CSAMT) profiles across a project and hope for the best. I’ll explain the problems with this exploration approach and a much better way to design an AMT survey.
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| Phil Wannamaker, University of Utah, Energy & Geoscience Institute
Website: https://egi.utah.edu/about/ Title: Three-dimensional magnetotelluric inversion using deformed hexahedral edge finite elements and direct solvers parallelized on SMP computers. Authors: Phil Wannamaker1, Michal Kordy1, Virginie Maris2, Elena Cherkaev1, and Graham Hill3 Outline: We describe a new algorithm based upon deformable hexahedral finite elements solving the electric field for 3D inversion of MT responses including substantial topographic variations. Direct solutions are used throughout, including the finite element system matrix, the jacobians and the Gauss-Newton parameter step matrix. The last step is achieved by transforming to data-space. Field examples utilizing of order one million parameters will be presented, run on single-box, large-RAM, multi-core workstations.
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