US Geological Survey in Pasadena Announces Groundbreaking ShakeAlert System Upgrade

In a significant advancement for earthquake early warning systems, the United States Geological Survey (USGS) team based in Pasadena announced a critical upgrade to the ShakeAlert System. The enhancement, which incorporates real-time satellite data alongside the existing network of over 1,500 seismic sensors, aims to expedite the detection and assessment of substantial earthquakes, particularly those exceeding magnitude 7.

The Pasadena area has recently been stuck by several small temblors.

“What we’ve been doing for several years now, since 2019, is that we’ve been delivering alerts to people’s phones and also initiating actions, automated actions using only seismometers,” said Robert de Groot, ShakeAlert System – Coordinator for Communication, Education, Outreach, and Technical Engagement at the USGS Earthquake Science Center in Pasadena.

“In addition to seismic data, which tells us how fast the ground is moving, we are now adding information about how far the ground is moving up, down, forward and back.”

This groundbreaking approach, spearheaded by the USGS in collaboration with the National Science Foundation’s EarthScope Consortium and multiple universities, enhances the system’s ability to swiftly characterize the magnitude and impact area of significant seismic events. 

By incorporating data from the Global Navigation Satellite System (GNSS), including the U.S.-based Global Positioning System (GPS), the ShakeAlert System augments its seismic measurements with precise ground movement data.

The ShakeAlert System is closest in design to the early warning system in Japan, which only incorporated seismic data during the 2011 Tohoku Oki earthquake. After the event, the Japanese combined seismic and GNSS data, similar to what the USGS is doing now.

“The GNSS data becomes important because one thing that we do know is that there is a relationship between how far the ground moves and how big an earthquake is,” explained de Groot. “It becomes most important as information about the earthquake gets updated over time.”

The integration of GNSS technology into the ShakeAlert System is expected to significantly expedite the dissemination of alerts, enabling prompt protective actions such as “Drop, Cover, and Hold On.” Currently operational in California, Oregon, and Washington, the system plays a pivotal role in safeguarding lives and critical infrastructure by delivering timely alerts via mobile devices and triggering automated safety measures.

“Anything we can do to preserve systems while they are shaking so that they can be used after,” emphasized de Groot, highlighting the importance of automated actions triggered by the ShakeAlert System, such as slowing trains, setting off PA systems, and opening and closing valves to protect water supplies.

The USGS works closely with organizations that use their data to deliver alerts, and any improvements these partners can make in processing and delivery on their end are also crucial. Additionally, the USGS conducts social science research to ensure that the communication and information sent to people is clear and prompts them to take action quickly.

As the ShakeAlert seismic sensor network continues to expand, with the USGS about 90% of the way built out of a total of 1,675 seismic stations and completion slated for the end of 2025, its coverage will extend to over 2,000 stations, fortifying public safety for more than 50 million residents and visitors across the three states. The USGS encourages individuals to learn how to receive ShakeAlert-powered alerts on their phones by visiting shakealert.org and to follow updates about the system on X (formerly Twitter) at @USGS_ShakeAlert.