WATCH: Research led by a UVic geologist has found an active fault under Vancouver Island’s most populated area. Isabelle Raghem reports
A study published by Kristen Morell and her team says they have discovered that the Leech River Fault, previously believed to be inactive, has caused at least two major earthquakes in the last 10,000 years.
“Previously it was thought that this fault was last active 50-million years ago and so this discovery adds a new piece of information about the hazard that that fault poses to the communities that are near it,” explains Morell.
The fault line runs a few kilometres from downtown Victoria to Clover Point.
Morell say discovering the fault is active could give a warning of what’s to come.
“There is the potential that [the Leech River fault could rupture in the future.”
Unlike the better known Cascadia Megathrust fault which is active every 300-500 years, the Leech River fault shows no activity for thousands of years.
“These smaller faults although they are smaller it’s harder to figure out if they’re active or not, and they don’t rupture very often, but when they do, they can be very destructive,” explains Morell.
The discovery comes at the same time other movements are happening right beneath our feet.
Experts at the Pacific Geoscience Centre say we are in a time period where thousands of unfelt tremors are taking place on the Island, indicating a slow-slip that could create the “Big One”.
“It’s a little tectonic dance that’s taking place here,” explains seismologist John Cassidy, “it’s ever so likely that a nudge could trigger that large earthquake.”
The cluster of tiny quakes has been migrating north over the last few days.
Kristen Morell says her team will now be working to learn a more exact time frame of when the quakes struck and their magnitude.