GPGN 308

Introduction to electrical & electromagnetic methods

Course Description:

This course covers the basics of electrical and electromagnetic (EM) methods in applied geophysics. The goals are to understand the theoretic basis, practical application, and data interpretation techniques of different electrical and electromagnetic methods commonly used in exploration, environmental, and groundwater problems. The course consists of two sections. In the first, we begin with the theory of electric-current field in conductive media. We then use it to discuss detection, mapping, and imaging methods that utilize various natural electrical fields, artificial direct current field, or induced polarization effect. In the second part, we first review the theory of electromagnetic induction and then use it to study EM methods for conductivity mapping and imaging based on both frequency- and time-domain measurements. We will emphasize field acquisition procedure, data processing, and data interpretation techniques within the context of the above-mentioned areas of application.

Course objectives
  1. Understanding the principles and basic theory of DC resistivity methods
  2. Understanding the principles and basic theory of electromagnetic induction methods
  3. Familiarity with the established field practices of data acquisition
  4. Basic interpretation techniques for different data sets
Course format
  1. Three one-hour lectures
  2. One three-hour lab
  3. Guest lectures during regular classes
Lecture topics:

The class will cover the listed topics below. The weekly schedule is a guideline that we will follow as closely as possible. However, additional auxiliary materials will be covered as needed, and the actual progress of the class will be slightly different.

Week - 1: Introduction: historical review, and rock conductivity
Week - 2: Electric current field in conductive media
Week - 3: Direct detection methods (mise-á-la-masse and SP)
Week - 4: Mapping methods
Week - 5: Vertical electrical sounding
Week - 6: Imaging methods
Week - 7: Imaging methods
Week - 8: Induced polarization
Week - 9: EM induction theory
Week - 10: EM induction theory
Week - 11: Time-domain EM methods
Week - 12: Time-domain EM methods
Week - 13: Airborne TEM
Week - 14: Frequency-domain EM methods
Week - 15: Frequency-domain EM methods
Week - 16: Future directions


Reynolds, J. M., 1998, An introduction to applied and environmental geophysics, Wiley (not required but highly recommended)

Credit Hours: 4