Geophysics 424 - Electromagnetic and potential field methods

September 2020 : These notes are temporarily offline as the material is being developed.

If you would like access, please e-mail me at unsworth@ualberta.ca

Course outline

Outline of 424 - Electromagnetic methods(PDF)

A : Overview of electromagnetic methods

  • A:Summary of Electromagnetic methods(PDF)

    B : Resistivity of rocks

  • B:Electrical resistivity of rocks

    C : Maxwell's equations

    C: Theory of EM field propagation in the Earth
  • atten_movie.m
  • atten_movie_colour.m

    D : Magnetotellurics

    D1:Theory of magnetotellurics over a 1-D Earth

  • MT_physics_correct_movie.m
  • Fit 1D model in MATLAB - TBT180 - Revised 2007

    Animations of 1-D MT sounding curves

  • Example 2 : Varying the depth of a layer
  • Example 3 : Constant conductance
  • Example 4 : Two layers : varying the conductance of the lower conductor

    D2:Theory of magnetotellurics over a 2-D Earth

    D3: Field techniques for Magnetotellurics exploration

    D4:Applications of magnetotelluric exploration

  • Analogue-to-digital-conversion (ts_tutorial_v1.m)

    E : Frequency domain electromagnetic methods

  • E1:Primary EM fields in the frequency domain

    E2 : Loop-loop EM systems in the near-field

  • E2.1 : EM responses of 1-D resistivity models
  • E2.2 : EM responses of a 2-D resistivity models
  • E2.3 : Generation of secondary EM fields
  • E2.4 : Applications of near-field frequency domain EM techniques

    E3 : Far field frequency domain EM exploration

  • E3: VLF, CSAMT and Marine CSEM

  • VLF_1.m Computes VLF fields over a conductor (MATLAB)
  • VLF_2.m Simulates use of a VLF instrument

  • Quicktime movie of an electric dipole in a conductor. f=0.25 Hz (courtesy Kerry Key)

  • E4 : Advantages and disadvantages of frequency domain EM methods

    F : Time-domain electromagnetic methods

  • F:Time-domain electromagnetic methods
  • input_EM_v1.m EM fields for the INPUT system
  • C6_time_domain_v1.m 6-channel airborne system
  • G : Ground penetrating radar

  • G1: EM wave propagation in the Earth
  • G2: Travel time curves for GPR
  • G3: Data collection and analysis techniques for GPR data
  • G4: Applications of GPR

    All GPR notes in a single PDF