The university's early warning project is intended to give residents a heads-up before an earthquake strikes and damage occurs.
To predict the quakes, scientists use a sensor to detect the arrival of the first round of waves called primary waves or p-waves. These waves are fast but rarely cause any damage. P-waves are followed by secondary waves or s-waves which are slower but do more harm.
ShakeAlert provided warning at the UC Berkeley Seismological Laboratory and to users in San Francisco, Oakland and San Jose. The system is being developed by UC Berkeley and the United States Geological Survey in cooperation with scientists at California Institute of Technology and University of Washington.