Calculating the Epicenter of An Earthquake

The purpose of this activity is for you to use seismic data to calculate the distance from three different seismic stations to the epicenter of an earthquake and to plot the derived data on a map in order to identify the latitude and longitude of the earthquake. The student will subsequently summarize their findings in writing by responding to a series of questions designed to evaluate the student’s understanding of the theory behind the calculation of an earthquake epicenter. In a final part of the activity, students will complete online research about the economic, cultural, environmental, and/or demographic impacts of a specific seismic event Calculating the Epicenter of An Earthquake Purpose: Part I: The purpose of part one of this activity is to help you, the student, understand how the epicenter of an earthquake is determined by having you: 1. use seismic data to calculate the lag times between the arrival of P and S waves at 3 seismic stations; 2. use a time travel curve and your calculated lag times to determine the distance the P and S waves traveled to each of the stations and 3. plot the data on a map to determine the epicenter of the earthquake. Part II: In part two of the activity, you will respond in writing to a series of questions designed to evaluate your understanding of the theory behind the calculation of an earthquake epicenter. Part III: In part three of the activity, you will complete online research about a specific seismic event and then determine the date, time, magnitude, location as well as economic, cultural, environmental, and/or demographic impacts of the seismic event. You will summarize your findings in your own words and in essay format. Background Information: Because P waves travel faster than S waves, the P wave arrives at a seismic station ahead of the S wave. The lag time between the arrival times of the two waves is directly related to the distance that the waves travel. Therefore, applying the seismic information derived from seismometers and applying it to the time travel curve, one can determine the epicenter of an earthquake.