Learning from Mexico's earthquake early warning system

The team spent several days visiting a series of locations, including a private school equipped with a dedicated siren system since 1993. The school experienced significant damage to two buildings on their campus, which were the administrative and preschool structures. During the earthquake, the teachers and students began evacuation as soon as shaking began but were unable to complete evacuations due to the strength of shaking. They chose to shelter in place and no injuries occurred at the school.

The recon team also interviewed dozens of locals — from Uber drivers to business owners —to understand what they expected from the system, in addition to how they responded to the alert. The warning came only after earthquake shaking began because the epicenter was so close to the city.

“Despite the late warning in Mexico City for the nearby M7.1 earthquake, people view the early warning system as necessary and valuable. They feel that since the technical capability exists to issue warnings, it should be used. It doesn’t prevent all damage or losses from earthquakes, and we knew that, but it does provide information to people,” Cochran said. “And, it turns out to also be a useful tool for strengthening their earthquake awareness and response to earthquakes.”

Coincidentally, the 19 September 2017, 7.1-magnitude Mexico earthquake occurred two hours after a national earthquake drill to commemorate the 32nd anniversary of the 1985 Mexico City earthquake. That devastating 1985 quake was what prompted the implementation of SASMEX.

The earthquake occurred only a short time after the sirens were sounded for the national exercise, but since shaking started prior to the alert sounding there was no confusion that this alert was an extension of the drill. People noted that they reacted more quickly when shaking started because the recent drill reminded them how to respond during shaking or when the siren sounds.

U.S. earthquake early warning: ShakeAlert
Nearly fifty million Americans are at risk due to earthquakes on the West Coast of the United States. Massive earthquakes on the Cascadia Subduction Zone or the San Andreas Fault system could cause billions of dollars in damage and cost thousands of lives.

“When fully operational, the ShakeAlert earthquake early warning system will save lives and reduce injuries and property damage,” said Robert de Groot, Coordinator for Communication, Education, and Outreach for the USGS ShakeAlert Earthquake Early Warning Project.

The USGS ShakeAlert system does not yet support public warnings, but in the near future a limited rollout will enable selected early adopters to develop pilot implementations that take automatic protective actions or notify trained personnel. The goal is to demonstrate the system’s utility and develop technologies that pave the way for broader use.