www.iris.edu/earthquake for more intro animations
Focal mechanisms are released after an earthquake to show what type of Earth movement produced the earthquake. These are typically shown using a socalled "beachball" diagram. They refer to the orientation of the fault plane that slipped and the slip vector, and are also called faultplane solutions.
Directed by Robert Butler, geophysicist, University of Portland
Animation & graphics by Jenda Johnson, Earth Sciences Animated
Narration: Roger Groom, Mount Tabor Middle School, Portland OR
Dr. Geophysics character: Richard Blakely, geophysicist, U.S.G.S.

Music: "Constellation" by Water Strider (http://www.waterstridermusic.com)
"Diagonal Stride" by Fadin' by 9 (http://www.fadinby9.com) written & fiddled by Seth Moran, seismologist U.S.G.S.

Reviewed by Anna Courtier, James Madison University, Harrisonburg VA
For more Earthscience animations, visit www.iris.edu/earthquake