Seismic Waves is a newsletter published by the National Earthquake Hazards Reduction Program [NEHRP]. "The 2008 'Great Southern California ShakeOut' was planned as a one-time event to motivate millions of people to practice 'Drop, Cover, and Hold On' and to get prepared at work, school, and home for the potential of a major earthquake. With the involvement of many partner organizations, the ShakeOut program has since expanded to include 42 states and U.S. territories, plus four other countries. More than 19.5 million people participated in 2012."
National Earthquake Hazards Reduction Program: http://www.nehrp.gov/
Seismic Waves (September 2013)