Magnitude 3.5 earthquake occurs near Tsawwassen, BC

Many British Columbians were jolted awake early Friday morning when an earthquake struck in the Strait of Georgia, about 11 miles (18 kilometers) southwest of Tsawwassen.

Earthquakes Canada initially said the quake had a magnitude of 3.8, but its website later reported a magnitude of 3.5. There were no reports of damage and, according to officials, these were not to be expected.

The 2:08 a.m. tremors were felt across a wide region, including southern Vancouver Island, Greater Vancouver and even the Fraser Valley and Washington state, said John Cassidy, a Victoria-based seismologist with Natural Resources Canada.

The earthquake occurred at a depth of 65 kilometers within the oceanic Juan De Fuca Plate.

“We are in what is called a subduction zone; “We have a sea plate off the coast of Vancouver Island that is moving toward us at about the same speed that fingernails grow,” Cassidy explained. “As it reaches North America just offshore, it begins to sink beneath Vancouver Island and continues to sink beneath the Lower Mainland as well as Washington and Oregon.”

The Juan de Fuca plate was responsible for another major earthquake of magnitude 3.8 last Thursday about 17 kilometers northeast of Victoria.

Cassidy says it's nothing out of the ordinary and seismologists haven't observed any changes in the plate's movement.

“The small events happen all the time, every year we see a dozen or more small, major earthquakes in the same area,” he told CTV News. “It's not really unusual, but it doesn't happen every day either, we see a magnitude 3.8 earthquake.”

He added that an earthquake of magnitude 5 or greater could cause damage in a populated center.

Another magnitude 4.6 earthquake struck in northern British Columbia at 4:09 a.m. Friday about 60 kilometers west of Fort St. John, and a handful of people reported mild tremors. According to Earthquakes Canada, there were no reports of damage.

“This morning's earthquake is really a good reminder to all of us that this is an active earthquake zone and we see tiny earthquakes every day that most people are not aware of, they are just too small and are not felt,” Cassidy said.

“Earthquakes like today are felt and are a good opportunity to check your earthquake gear and emergency equipment and also sign up for the shakeout drill.”

The Great BC Shakeout will take place on October 17th, where people can practice dropping, covering and holding on in the event of a major earthquake.

With files from Spencer Harwood of CTV News Vancouver