More than 150 tremors hit Vancouver Island in 24 hours –
Vancouver Island is normally moving toward the Lower Mainland at a rate of about one centimetre per year.
every 14 months or so there is a Tremor and Slip event – a discovery made by two local scientists Gary Rogers and Herb Dragert – when Vancouver Island slips backwards a few millimetres towards Japan. Seismic recording instruments show Victoria moving in one direction and then changing direction for about two weeks during these episodes. These events add pressure to the locked Cascadian Subduction Zone fault.
“It involves tiny tremors that we can record. They are not earthquakes. People don’t feel these shaking events. But we can easily record them over many seismic stations at the same time,” said Cassidy. “It looks like a train or a rumbling.”
VICTORIA — Hundreds of tiny tremors
VICTORIA — Hundreds of tiny tremors, felt only by sensitive monitors, have shivered under southern Vancouver Island in the last 48 hours, leading one scientist to predict they may signal what he calls a “tectonic dance.”
John Cassidy, an earthquake seismologist with Natural Resources Canada, says the shaking has most of the hallmarks of a so-called episodic tremor and slip, a process that occurs along the fault lines at the edges of tectonic plates.