Locating Earthquake Epicenters

In this exercise, students use data from the 1994 Northridge, California, earthquake to locate the earthquake and its time of occurrence, and plot data from Central and South America on a map to delineate plate boundaries. Introductory materials explain how earthquakes are caused, describe the types of seismic waves, and explain that the difference in arrival times may be used to calculate distance to the earthquake. Each portion of the exercise includes instructions, datsets, maps, travel-time graphs, study questions, and tables for entering data. A bibliography is also provided. Educational levels: High school, Undergraduate lower division