Magnetotellurics for Natural Resources:
From Acquisition through Interpretation

by Karen Christopherson

Duration: Two days

Intended Audience: Entry level

Prerequisites (Knowledge/Experience/Education Required):
The course is intended to give an overview of how Magnetotellurics can be applied to exploration problems, with details provided on all aspects of the technology. Hence, anyone with some geoscience background can attend, from geophysicists to geologists to managers. The outcome from the course will be different for each person, depending on what the person would like to gain. The instructor will do her best to provide the information needed so that all attendees questions are answered. Whether it is how to design an effective survey, how to interpret MT data, how to use MT workstations or where the technology is best applied. The level of detail provided in the course is detailed in many aspects, but also provides a good overview of Magnetotellurics.

In the last fifteen years the use of magnetotelluric and audio-magnetotelluric methods for resource exploration and exploitation has increased significantly and there is a need for the geophysicist to better understand the theory, application and interpretation of  magnetotelluric (MT) and Audio-MT methods. This course will provide the interested geophysicist with the knowledge and skills necessary to design and manage cost-effective MT field programs and to understand the data processing and interpretation issues. Over the two days of the course the following topics will be investigated: theory, applications and acquisition, processing and interpretation of data. MT interpretation software demonstrations will be included. Attendees will be polled prior to the course as to what their interests are, and curriculum revised accordingly. The course can be structured to mineral, petroleum, geothermal and/or groundwater exploration. Emphasis can be shifted from the more theoretical to practical (including case histories, guest lectures, and computer hands-on software trials) as attendees prefer.

Course Outline:

  • Theory
    1. Maxwell's equations and fundamental physics of technique
    2. Source fields
    3. History
  • Applications
    1. Where it can/cannot be used
    2. Limitations – cultural noise
    3. Targets
    4. Resolution
  • Acquisition/Equipment
    1. Equipment manufacturers
    2. Types of arrays
    3. Logistics
    4. Planning a survey
    5. Cost effectiveness
    6. QC of data during acquisition
  • Processing
    1. Standard parameters
    2. Noise reduction/filtering
    3. Routine processing
    4. 'Robust' processing
  • Interpretation
    1. 1D – Forward and inverse, limitations
    2. 2D – Forward and inverse, limitations and caveats
    3. 3D – Current codes, benefits, demonstration and case histories
    4. Workstations – WinGLink, Geotools, others
    5. Output – Cross-sections and maps
    6. Integration with other geophysical methods, geology, and well information

Learner Outcomes:

1.    Understand the basic physic involved in MT
2.    Know what the two key MT source fields are, and their behavior
3.    Define the basics of MT acquisition - what fields are acquired, how and why
4.    Realize the various ways to process MT data
5.    Describe how the numerous MT parameters are utilized in MT interpretation
6.    Distinguish between 1D, 2D, and 3D interpretation methods
7.    Understand the steps and needs for completing a good MT field acquisition program and interpretation

Instructor Biography:
Karen Christopherson