No tsunami or damage reported after multiple tremors off B.C.

VANCOUVER — A series of earthquakes off British Columbia’s coast on Friday may be linked to a stronger quake in the same area earlier in the week, experts say.

Alison Bird, a seismologist with the Pacific Geoscience Centre near Victoria, said they are working to determine if the latest tremors are aftershocks from Wednesday’s 6.2 magnitude quake in the same region.

“I’m starting to wonder if this might be more of a swarm sequence than a main shock, aftershock sequence,” she said.

A swarm sequence is an outbreak of seismic activity, which is common off the B.C. coast.

“It often has a sudden flurry of activity where you get 100 earthquakes within a week-and-a-half period,” she said. “They’re a bit of a nuisance.”

The quakes occurred under the Pacific Ocean between Haida Gwaii and the northern tip of Vancouver Island. Bird said she had calculated two larger tremors, one occurring at 5:58 a.m. Pacific time Friday, with a preliminary magnitude of 5.1 and a second four minutes later measuring 4.7. None set off a tsunami and no damage or injuries were reported.

The U.S. Geological Survey initially set the magnitude of the most significant tremor at 5.6, but Bird said different interpretations are common in the first hours after a quake as seismologists work to hone the information.

Southern California experienced a 6.4 earthquake on Thursday. Bird says the B.C. quakes and California’s quake are unconnected and didn’t occur in the same fault zone.