Natural Resources Canada
A M1.7 earthquake struck 11 kilometers southwest of Victoria on Thursday afternoon.
Natural Resources Canada says it hit a 3:38 p.m. at a depth of 16.3 kilometers.
It comes as seismologists continue watching seismic activity after more than 250 tiny tremors struck over much of south and central Vancouver Island over the 24 hours earlier this week.
Seismologist John Cassidy reported the tremors on Twitter from the Pacific Northwest Seismic Network, saying the events stretched from Port Alberni to Cowichan Lake and moving towards Bamfield.
Cassidy says the activity is looking like an Episodic Tremor and Slip (ETS) event, which happens deep below the Earth’s surface along faults that make up tectonic plate boundaries.
Earthquakes Canada says an ETS involves “repeated episodes of slow fault slip of a few centimetres over a period of several weeks, accompanied by seismic tremors.”
Although all aspects of ETS are not fully understood, the importance of them may help give improved estimates of where and when a much bigger earthquake is likely to happen.
More than 250 tiny tremors stretching over south-central Vancouver Island, which were not felt struck earlier this week. Photo courtesy Twitter/John Cassidy/PNSN.
Ben O'Hara
