PASADENA, Calif. — Today, the U.S. Geological Survey and its partners are announcing a new capability to characterize large earthquakes quickly, helping inform the public about potentially damaging shaking headed their way. In addition to over 1500 seismic sensors that detect ground shaking, the ShakeAlert System now makes use of sensors that detect earth-surface movement via satellite.

“While rare, earthquakes greater than magnitude 7 can have the greatest impact on human lives and infrastructure,” said Robert de Groot, with the USGS ShakeAlert Operations Team. “Future major offshore earthquakes in the Pacific Northwest, which could be similar to the 2011 M 9.1 earthquake in Japan, underscore the importance of incorporating satellite data stream into the ShakeAlert System.” 

The newly added ShakeAlert capability that uses data from real-time Global Navigation Satellite System sensors may more quickly and accurately determine the magnitude and the area of shaking from very large earthquakes, resulting in faster notifications for people to take a protective action, such as Drop, Cover, and Hold On. GNSS data, which includes the well-known US-based Global Positioning System, are now used in addition to seismic data to detect earthquakes. While seismic sensors measure how quickly the ground is shaking, GNSS sensors measure how far the ground moves up, down, or sideways during an earthquake. 

The ShakeAlert System, currently available in California, Oregon, and Washington, can protect people and infrastructure by delivering alerts to cell phones and triggering automatic actions like slowing down trains to prevent derailments, opening firehouse doors so they don’t jam shut, and closing valves to protect water systems.  

The ShakeAlert GNSS integration and ongoing operations is a partnership of the USGS, the National Science Foundation funded EarthScope Consortium, university partners with significant contributions from the University of Washington, Central Washington University, UC Berkeley, and the Pacific Northwest Seismic Network. 

The ShakeAlert Earthquake Early Warning System is managed by the U.S. Geological Survey in partnership with state agencies and universities and it is a public safety tool for over 50 million residents and visitors in California, Oregon, Washington. When the ShakeAlert seismic sensor buildout is completed at the end of 2025 there will be a network of over 2000 ShakeAlert stations poised to protect residents and visitors in California, Oregon, and Washington. 

For more information on how this new capability works, watch this video.