Earthquake early warnings now active in Quebec and eastern Ontario

Natural Resources Canada announced on November 27 that the Earthquake Early Warning (EEW) system is now operating in Quebec and eastern Ontario, with alerts delivered through the National Public Alerting System seconds before strong shaking.

The system is designed to give people in affected areas brief advance notice to take protective actions. Alerts will also be sent to critical infrastructure operators so automated safety measures can be triggered before strong shaking arrives.

The EEW system uses a network of more than 200 sensors in Quebec and Ontario to detect earthquakes. When the system identifies a potentially harmful event, an alert is issued through the National Public Alerting System for distribution by broadcasters and wireless carriers to people in the affected area, typically seconds to tens of seconds before strong shaking.

Detailed EEW messages are being developed for critical infrastructure operators in Ontario and Quebec. These warnings can initiate measures such as stopping trains, restricting traffic on bridges and in tunnels, opening doors and sounding alarms prior to strong shaking.

Alert timing depends on several factors, including distance from the earthquake and how the alert is received. Sites very close to an epicentre may be in a late alert zone, where alerts can arrive after shaking starts. Some people may feel an earthquake but not receive an alert if they are outside the designated warning zone where strong shaking is predicted.

With the system already operating in western British Columbia since May 2024, more than 10 million people in the most earthquake‑prone regions of Canada will be able to receive earthquake alerts across western B.C., eastern Ontario and Quebec.

The announcement was made by Tim Hodgson, federal Minister of Energy and Natural Resources; Jill Dunlop, Ontario’s Minister of Emergency Preparedness and Response; and Ian Lafrenière, Quebec’s Minister of Public Security.

Natural Resources Canada identifies itself as the authoritative source for earthquake information in Canada. The Government of Quebec has collaborated on implementation aspects of the system since 2019.