Earthquake early warning systems use earthquake science and the technology of monitoring systems to alert devices and people when shaking waves generated by an earthquake are expected to arrive at their location. The seconds to minutes of advance warning can allow people and systems to take actions to protect life and property from destructive shaking.
Even a few seconds of warning can enable protective actions such as:
- Public: Citizens, including schoolchildren, drop, cover, and hold on; turn off stoves, safely stop vehicles.
- Businesses: Personnel move to safe locations, automated systems ensure elevators doors open, production lines are shut down, sensitive equipment is placed in a safe mode.
- Medical services: Surgeons, dentists, and others stop delicate procedures.
- Emergency responders: Open firehouse doors, personnel prepare and prioritize response decisions.
- Power infrastructure: Protect power stations and grid facilities from strong shaking.
EEW systems are currently operating in several countries, and others are building them. Since 2006 the USGS has been working to develop EEW for the United States, with the help of several cooperating organizations including the California Geological Survey (CGS), the California Institute of Technology (Caltech), the California Office of Emergency Services (CalOES), the Moore Foundation, the University of California, Berkeley, the University of Washington, and the University of Oregon. The goal is to create and operate an EEW system for the highest risk areas of the United States beginning with the West Coast states: California, Washington, and Oregon.
A demonstration EEW system called ShakeAlert began sending test notifications to selected users in California in January 2012. The system detects earthquakes using the California Integrated Seismic Network (CISN),an existing network of about 400 high-quality ground motion sensors. CISN is a partnership between the USGS, State of California, Caltech, and University of California, Berkeley, and is one of seven regional networks that make up the Advanced National Seismic System (ANSS).
In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California. This “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost. This next-generation system will not yet support public warnings but will allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert warnings in areas with sufficient coverage. The USGS has published an Implementation Plan with the steps needed to complete the system and begin issuing public alerts.
- USGS Fact Sheet on Early Warning and ShakeAlert
ShakeAlert—An Earthquake Early Warning System for the United States West Coast
- ShakeAlert wbsite
- Video - ShakeAlert—Earthquake Early Warning. How Does It Work?
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- Video example of the ShakeAlert display on a test user’s computer