In September 2017, Ocean Networks Canada's (ONC) seismic sensors collected real-time information on two recent and very different earthquakes: one distant quake off Mexico’s west coast and a much smaller regional event near Ucluelet, British Columbia. Both seismic events provide insight into British Columbia’s earthquake early warning system, currently in development.

Early warning for Mexico’s magnitude 8.1 earthquake

On 7 September, a magnitude 8.1 earthquake struck off Mexico’s southwest coast near the Guatemalan border. ONC’s sensors detected the seismic waves over 4,700 kilometres away (Figure 1).