UC Berkeley System Gave Early Warning of South Napa Earthquake

Five seconds before the South Napa Earthquake struck, UC Berkeley's ShakeAlert detected the quake.

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.


Last September, Governor Jerry Brown approved a bill to create an early warning system. The bill requires that sensors be installed to detect earthquakes and that operators figure out a way to alert the public.

However, ShakeAlert doesn’t have enough backing to scale up, according to Richard Allen who directs the Berkeley Seismological Laboratory.

It will cost $80 million over five years to test and deploy the system and another $12 million a year for operational costs.

After Alaska, California experiences more earthquakes than any other state and an early warning system could provide a model for others, if it receives enough funding.

Currently there is no national early warning system.

Instead, under the Disaster Relief Act of 1974, the USGS must issue alerts and improve public safety around earthquakes. While USGS already sends rapid, automatic earthquake information via the Internet, email, text messages and social media it does not currently employ an early warning system.

Funds to test ShakeAlert are currently provided by the Bay Area Rapid Transit System, Google, the City of San Francisco and The Gordon and Betty Moore Foundation. But it will take a long term financial commitment in order to keep the system running.