Alaska GPS Analysis of Plate Tectonics and Earthquakes

Robert Butler (University of Portland), Beth Pratt-Sitaula (EarthScope Consortium) and ANGLE Project
EarthScope Consortium logo. Concentric circles in red grading to purple.
Author Profile


This activity introduces students to high precision GPS as it is used in geoscience research. Students build "gumdrop" GPS units and study data from three Alaska GPS stations from the Network of the Americas. They learn how Alaska's south central region is "locked and loading" as the Pacific Plate pushes into North America and builds up energy that will be released in the future in other earthquakes such as the 1964 Alaska earthquake.

Used this activity? Share your experiences and modifications



This activity can be done with introductory geoscience learners in secondary school or early college. It takes a 2-3 hours of time total. With secondary students it would probably be best split over 2-3 days. Early college level could probably complete at home after starting in class.

Skills and concepts that students must have mastered

,Learners should be familiar with plate tectonics and earthquakes. The instructor should definitely give a brief introduction to GPS systems at the start of the activity if the students are not already familiar.

How the activity is situated in the course

This activity would probably be best midway or late in a unit on plate tectonics and earthquakes or geoscience and hazards.


Content/concepts goals for this activity

Students will be able to:

  • Diagram and describe the basic components of the GPS system and a GPS station
  • Construct a small model GPS station
  • Interpret high precision GPS data

Higher order thinking skills goals for this activity

  • Calculate tectonic velocities from GPS time series data and graph resulting vectors
  • Synthesize results from three GPS stations to determine the implications for future earthquakes in south central Alaska.

Other skills goals for this activity

Description and Teaching Materials

Overall this activity has five sections. The first two are relatively faster hands-on demonstration activities to introduce learners to GPS. The next three steps learners through measuring, plotting, and interpreting GPS data.

  1. Building a GPS 'Station'
  2. Pinpointing a Location with GPS
  3. Measuring Alaska GPS/Tectonic Movement
  4. Plotting GPS Station Motion
  5. Analysis of GPS Station Motion

Teaching Materials

Two similar activities featuring Pacific Northwest GPS data are available from the Cascadia EarthScope Earthquake and Tsunami Education Program (CEETEP)

Teaching Notes and Tips

  • See also the Instructor Notes document above.
  • If an instructor wishes to shorten the exercise and concentrate just on the vector and math portions of the exercise, the first two sections could be skipped and just replaced (if needed) with a brief introduction to what GPS is.
  • If instructors wish to update the data in the activity, they can download it from the GPS station pages.
    Access Data from Your Closest GPS station (Acrobat (PDF) 2.1MB Oct28 22) - 1-page document that walks through how to access GPS data from any of the stations in the Network of the Americas (NOTA). Stations used in this activity are:


Formative assessment of student understanding can be gathered from classroom observation and discussions with individuals or small groups.

The student exercise serves as the summative assessment for the activity. Some questions have clearly correct answers. Teachers can develop a simple grading scheme for open ended questions such as:

  • 2 points for thorough and correct answer
  • 1 point for partially correct
  • 0 zero for incorrect

References and Resources