Vancouver Island is normally moving toward the Lower Mainland at a rate of about one centimeter per year. “Ferry fares keep going up but the distance is actually getting a little bit shorter,” jokes John Cassidy, a seismologist with the Geological Survey of Canada. But 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 backward a few millimeters 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.” READ MORE
