Canada's Vancouver Island has been jolted by a string of earthquakes and their aftershocks since Monday, but residents have barely noticed because the tremors are so far offshore. The latest and most powerful quake—registering magnitude 5.5 on the Richter scale—ripped through the Pacific Ocean floor off the island's west coast at 5:37 A.M. Pacific Daylight Time, according to Natural Resources Canada.

Though more vigorous than those experienced in the area in years past, the quakes are not causing alarm at the Ministry of Public Safety's Emergency Management British Columbia.

Strings of small earthquakes, known as a so-called "earthquake swarm," are not new to this seismically active region. Researchers attribute it to thinner fault lines in this particular area of the Pacific, and say that the cracking of Earth's crust is a normal occurrence.