Four earthquakes hit Haida Gwaii
Posted March 14, 2013 6:05 pm.
This article is more than 5 years old.
VANCOUVER (NEWS1130) – Four earthquakes have occurred off the north BC coast, the latest in a series that has rattled the area since last fall.
According to Earthquakes Canada the quakes with magnitudes 4.3, 4.0, 3.9, and 3.6 struck south and southwest of Sandspit on the Haida Gwaii islands.
Two other quakes of similar magnitudes occurred in February in the same region.
According to Michael Bostock of UBC’s seismology department, they are still the after-effects of the 7.7 earthquake of Haida Gwaii back in October.
The aftershocks and even the odd mid-sized earthquake are very common even months after the initial earthquake.
“When you have a major rupture like that, you do alter the stress field in the region. There is a regular readjustment that occurs. But we should see these earthquakes tail off,” he explains.
“There shouldn’t be any large earthquakes in the immediate future, but experience from places like Italy tells us earthquakes are very unpredictable,” he notes.
In 2009, a deadly earthquake hit L’Aquila, Italy, after months of smaller tremors. Scientists had told residents the tremors were not a warning that a large earthquake was in the making.
Bostock points out it’s impossible to monitor the factors that determine where an earthquake will occur, like the state of the stress on the earth’s crust and the movement of fluids in that crust.
Looking back, he says considering the magnitude of the October quake, it’s amazing nothing was damaged and no one was hurt.
