This learning video uses a simple analog setup to explore why earthquakes are so unpredictable. The setup is simple enough that students should be able to assemble and operate it on their own with a teacher's supervision. [22:48]

This video segment adapted from NOVA uses historical illustrations, photographs, and animations to explain how seismographs work, the difference between P and S waves, and the Richter scale.

Video clip provides a definition of moment magnitude and why it replaced the Richter Scale. [5:40]

This animation uses a gridded sphere is to show that: 1) the seismic stations don't need to be lined up longitudinally to create travel-time curves, as they appear in the first animation, and 2) a single station records widely separated...

This animation uses a gridded sphere is to show a single station recording five equidistant earthquakes. [0:44]

Scientists have developed far-more sensitive seismometers that, with faster computers, have enabled them to record & interpret a broader spectrum of seismic signals than was possible in the 1930's, when the Richter magnitude was...

See how a 3-Component seismogram records seismic-wave motion. [2:53]

This playful animation describes what a seismogram is, how they are recorded and what to look for in the seismic traces recorded on a seismometer. [4:26]

In this animation take a look at two magnitude scales, and use two examples of magnitude changing. [6:54]