Haida Gwaii residents did not report feeling a light earthquake off the archipelago's south coast on Feb. 2.
The 4.9 magnitude quake struck 50 km south of Rose Harbour at approximately 4:30 p.m. local time. The intensity near the epicentre was higher, but since this occurred offshore, the intensity on land was quite low.
“Generally, earthquakes of these intensities are rarely felt,” said Camille Brillon, seismologist at Natural Resources Canada.
There was no tsunami or Earthquake Early Warning (EEW) issued. An EEW notification is sent in areas with moderate to high earthquake hazards and ones with concentrations of population and infrastructure.
On the morning of Feb. 3, analysts at Natural Resources Canada reviewed the event and found that the magnitude had decreased to 4.3.
“While not felt, last night’s earthquake is a reminder that offshore Haida Gwaii has the potential to host significant earthquakes,” said Brillon.
In the event of an earthquake on or near Haida Gwaii, in which one feels shaking or receives an EEW alert, people should immediately ‘Drop Cover and Hold on” to protect themselves from objects that may move during an earthquake. If shaking lasts longer than 60 seconds and one is in a tsunami hazard zone, people must evacuate to high ground.
Brillon reminds residents to have an emergency kit and plan ready to sustain their family for at least 72 hours. Emergency planning guides can be found on PreparednessBC.
If someone feels an earthquake, they should report it on Earthquakes Canada’s website.
The duration of shaking experienced during an earthquake depends on several factors, including the earthquake’s magnitude, a person’s location relative to the epicentre, the type of ground they are on, and the type of building they occupy. This shaking can range from a slight rumble to several minutes in length.
“The 2012 M7.8 earthquake offshore Haida Gwaii had perceived shaking lasting up to two minutes, with strong shaking lasting 30 seconds,” said Brillon.
