GETSI Teaching Materials >GPS, Strain, and Earthquakes
GETSI's Earth-focused Modules for Undergraduate Classroom and Field Courses
showLearn More
This module is part of a growing collection of classroom-tested materials developed by GETSI. The materials engage students in understanding the earth system as it intertwines with key societal issues. The collection is freely available and ready to be adapted by undergraduate educators across a range of courses including: general education or majors courses in Earth-focused disciplines such as geoscience or environmental science, social science, engineering, and other sciences, as well as courses for interdisciplinary programs.
Explore the Collection »
show Download
The instructor material for this module are available for offline viewing below. Downloadable versions of the student materials are available from this location on the student materials pages. Learn more about using the different versions of GETSI materials »

Download a PDF of all web pages for the instructor's materials

Download a zip file that includes all the web pages and downloadable files from the instructor's materials

GPS, Strain, and Earthquakes

advanced level course Vince Cronin (Baylor University)
Phillip Resor (Wesleyan University)
6-Unit Technical Advisors: Bill Hammond and Corné
Kreemer (University of Nevada Reno)
Editor: Beth Pratt-Sitaula (UNAVCO)

Summary

Understanding how the Earth's crust deforms is crucial in a variety of geoscience disciplines, including structural geology, tectonics, and hazards assessment (earthquake, volcano, landslide). With the installation of numerous high precision Global Positioning System (GPS) stations, our ability to measure this deformation (strain) has increased dramatically, but GPS data are still only rarely included in undergraduate courses, even for geoscience majors. In this module students analyze GPS velocity data from triangles of adjacent GPS stations to determine the local strain. Students learn about strain, strain ellipses, GPS, and how to tie these to regional geology and ongoing societal hazards. A case study from the 2014 South Napa earthquake helps students make connections between interseismic strain and earthquake displacements.

Strengths of the Module

Most structural geology courses only cover finite strain (generally through the analysis of deformed fossils), missing the rich opportunity to investigate ongoing strain (infinitesimal strain) now measurable through methods such as GPS. This module introduces geoscience majors to Plate Boundary Observatory (PBO) GPS data in order to study infinitesimal strain and connect it to broader tectonic settings and hazards.

The earlier units help ground the students in the societal impact of earthquakes and give them an opportunity to explore strain and deformation through a variety of physical models ranging from Silly Putty® to drywall compound. This affective and intuitive introduction to strain provides a firm foundation from which to learn about strain quantitatively.

Students work with GPS velocity data in sets of three stations in the same region that form an acute triangle. By investigating how the ellipse inscribed within this triangle deforms, students learn about strain, strain ellipses, GPS data, and how to connect these to regional geology and hazards. The calculations can be done using provided Excel or Matlab calculators (most typical) or students can be asked to do the calculations or coding themselves.

The Unit 6 summative assessment has the students select a set of three GPS stations in an area of interest to themselves. For many students this is their first experience with "research" and possibly their first time giving an oral presentation. Despite initially being daunted by this idea, students generally end up doing well on it and gaining notable confidence with GPS data.

Great fit for majors-level classes in:

  • structural geology
  • geophysics
  • tectonics
  • geohazards
  • applied physics
  • applied engineering

Instructor Stories: How this module was adapted
for use at three different institutions »



      Next Page »

Already used some of these materials in a course?
Let us know and join the discussion »

Considering using these materials with your students?
Get advice for using GETSI modules in your courses »
Get pointers and learn about how it's working for your peers in their classrooms »

This module is part of a growing collection of classroom-tested materials developed by GETSI. The materials engage students in understanding the earth system as it intertwines with key societal issues. The collection is freely available and ready to be adapted by undergraduate educators across a range of courses including: general education or majors courses in Earth-focused disciplines such as geoscience or environmental science, social science, engineering, and other sciences, as well as courses for interdisciplinary programs.
Explore the Collection »