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
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)
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.