How can we see the layers of the Earth? A CAT (computed axial tomography) scan animation is included because seismic tomography is often compared to CAT scans. [2:34]

In this instructional sequence, students examine seismic evidence to determine that the Earth must have a layered internal structure and to estimate the size of Earth's core.

Earth's interior is broadly grouped into three main layers on the basis of chemical composition: crust, mantle, and core. An egg analogy is used to show relative thicknesses, and a Big Hunk analogy illustrates how a material of a single...

This animation addresses regional and local tectonics, earthquake occurrences and historic earthquakes, crustal fault earthquakes (Kobe, 1995), megathrust earthquakes (Tohoku-Oki, 2011), and tsunamis. [10:04]

A middle school science teacher demonstrates how a slinky is a good analogy for P & S seismic waves. [5:13]

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

Learn how foreshocks and aftershocks are related to the main shocks of earthquakes. [6:32]

This demonstration shows that seismic waves propagate in all directions in the Earth from the source (not just in the direction of a single slinky). [5:13]

See how to model differential friction along a fault. [2:30]

This demonstration shows that rocks are elastic by squeezing a slit core of solid rock. Energy is stored as potential energy while the rock is squeezed. [1:22]

See a demonstration of an earthquake slip-stick behavior in the classroom. [6:22]