SIGkit (Software for Introductory Geophysics toolkit) for modelling and visualization of data
Learning outcomes that are common for the set (separate activities for gravimetry, magnetometry, resistivity, electromagnetics, ground-penetrating radar, and seismic refraction) are that students will be able to
- explain key concepts, including the relationship between parameters used to describe an object and geophysical data,
- estimate physical parameters for an object (and recognize non-uniqueness of solutions), and
- match a synthetic model to real data.
To our knowledge this toolkit provides the first teaching software that brings together various methods and corresponding data sets into a comprehensive learning software. The activities in their current form are based on a collection of MATLAB scripts; ie, they require students to have access to MATLAB.
Skills and concepts that students must have mastered
How the activity is situated in the course
Activity LengthThis activity is made up of 6 half-day modules.
Content/concepts goals for this activity
- gravity: effect of depth and density on a gravity anomaly of a 2D object
- magnetics: magnetic anomaly for a 2D object and parameters (magnetic latitude, profile azimuth, height of sensor, total field intensity and gradient, induced and remanent magnetization), allows for extraction of profile from a map
- resistivity: resistivity sounding curve, apparent versus true resistivity, equivalent layer principle
- electromagnetics: apparent conductivities, vertical and horizontal coils (activity incomplete because no data set included)
- GPR: two-way time versus depth, imaging artefacts (diffraction hyperbolae, bow ties)
- seismic refraction: travel-time curves for horizontal 2-layer case, picking first breaks, hidden layers
Higher order thinking skills goals for this activity
- predict data for given model parameter,
- test predictions against real data,
- analyze field data, including self-collected data, and
- recognize the non-uniqueness of geophysical models and interpretation.
Other skills goals for this activity
- working in groups
- arguing their case (eg, why to use a certain setup for a field survey)
Description and Teaching Materials
The activity includes a set of handouts for students explaining how to run the software, engaging them in a guided tour of key concepts for the 6 methods, and allowing them to explore real data. The software is provided as a set of scripts in a directory which needs to be unzipped. The computer students want to run these scripts from needs to have MATLAB installed.
activity handouts (Acrobat (PDF) 568kB Apr3 19)
SIGkit_noGUI.zip (Zip Archive 5.4MB Apr3 19)
Technology NeedsThis activity required MATLAB.
Teaching Notes and Tips
Instructors wishing to see results for the example data please email me (provide a link to your institutional website) and I will forward you that information.
Please let us know of any errors, confusions, and suggestions for improvement.