Department of Earth Science |Northeastern Illinois University

ESCI 121
Spring 2006

Daily Objectives #17 (March 14, 2006)                                                                        Dr. Sanders

By the end of today’s class, you should be able to do the following:

* Explain how a seismograph works.

* Explain how we measure the magnitude of an earthquake using the Richter scale.

* Explain how we classify the intensity of an earthquake using the Mercalli scale.

* Explain what P- and S-waves are, and how they move through solid and liquid material in the earth.

* Explain why it is necessary to have data from at least three seismometers to pinpoint the epicenter of an earthquake.

* Using data on arrival times of P and S waves for four seismometers, locate the epicenter of an earthquake. 

Department of Earth Science | Northeastern Illinois University

© 2006 Laura L. Sanders.  Last updated March 14, 2006.