Students learn how engineers characterize earthquakes through seismic data. Then, acting as engineers, they use real-world seismograph data and a tutorial/simulation accessed through the Earthquakes Living Lab to locate earthquake epicenters via triangulation and determine earthquake magnitudes. Student pairs examine seismic waves, S waves and P waves recorded on seismograms, measuring the key S-P interval. Students then determine the maximum S wave amplitudes in order to determine earthquake magnitude, a measure of the amount of energy released. Students consider how engineers might use and implement seismic data in their design work. A worksheet serves as a student guide for the activity.