Southwestern British Columbia is recovering from the shock of Friday’s earthquake, which has triggered some concern about the consistency and timing of alerts sent to residents.
A federal seismologist says they are looking into the issue, but some variance on alerts sent to mobile devices can and does occur.
The earthquake, which is now rated by Natural Resources Canada at a magnitude of 4.7 centred 24 kilometres north-northeast of Sechelt, B.C., on the Sunshine Coast, has been followed by a number of aftershocks between 1.0 and 2.0 in strength.
A number of residents including Campbell River, B.C., teacher Nat Raedwulf Pogue posted on social media that they experienced shaking strong enough to make them consider taking cover but received no warning on their cellphones.
Raedwulf Pogue says in an interview that she is “really concerned” some people who felt strong shaking did not receive an alert, especially given her job as a teacher working with students with disabilities who would need as much early warning as possible.
Natural Resources Canada seismologist Alison Bird says the alerts sent from the ministry’s Earthquake Early Warning system “are being evaluated,” and the timing of when people would receive a warning depends on both their distance from the earthquake and how they receive the alerts.
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Bird says the alerts on Friday were only issued in an area around the quake’s epicentre where “strong shaking” was expected, but some people outside the zone may have also received those warnings.
“Some people outside the area for EEW alerting may have received the alert because their device was able to receive a signal from a cell tower that is within the EEW area,” Bird says in a written response. “Everyone within the area of strong shaking … should have received the alert, however.”
Bird also says there may be confusion over the federally sent alerts specific to earthquakes and the provincial system—which notifies residents of “significant events” that may also include wildfires and other disasters.
There has been no report of damage from the quake, which occurred at 1:26 p.m. local time on Friday at a depth of about one kilometre.
