This learning module looks at earthquakes. It discusses areas of earthquake activity, how they are measured using the Richter scale, and how scientists try to predict earthquakes. Includes handouts, slideshows, activities, and videos.

Explains what the Richter scale is and how the Richter formula is used to measure the magnitude of earthquakes. Includes a table of Richter values showing the changes in characteristics, impact, and frequency of tremors and earthquakes...

This website explains how the Richter and Mercalli Scales work.