Find out why the solid-seeming earth is actually a changing body, constantly destroying and rebuilding itself. Tectonic plates' movements are clearly demonstrated as the source of these alterations through exciting live-action and computer graphic images. Viewers learn how seismology helps reveal the earth's structure, how the plates' collisions create earthquakes, and how the Richter scale works. Other earthquake-related such as amplitude, magnitude, aftershocks, subduction, and epicenter are illustrated in clear detail, and the program shows why plate tectonic theory is the foundation of modern geology. 3y59e