It is very hard to imagine how big an earthquake can be. One way to understand their size is to compare one earthquake to another, using the records made by seismographs. Take a look at the records of one of the most famous earthquakes, and compare it to others from this decade. Records of earthquakes that happened decades ago explain how the earth moved as well as the effects of these earthquakes.

Look at the seismograph of the incredibly powerful earthquake of 1906, then click on "1989 Loma Prieta earthquake" to compare the two earthquakes. 1906 Earthquake

Examine the record of at least three of the large earthquakes that occurred in California during the 1990s. Recent Earthquakes

Try to reproduce the movement of each of these three earthquakes by shaking a table or desk. If you visit The Tech Museum, check out a shaking platform that helps you experience how it felt to be in many of these quakes.