B.C.'s micro-quake swarm not likely to lead to eruption

Last Updated: Thursday, October 25, 2007 | 11:03 AM PT

CBC News

Intense volcanic activity appears to be behind hundreds of tremors in B.C.'s Central Interior, but the chance of a volcanic eruption is minimal, experts say.

Attention was drawn to an area about 100 kilometres west of Quesnel when a series of micro-quakes reaching a magnitude of 2.7 were recorded over a number of days earlier in October.

Scientists moved quickly to determine whether the micro-quakes might indicate a volcanic eruption was brewing beneath the Earth's surface.

Five additional seismographs were moved into the location of the tremors, about 20 kilometres west of the Nazko Cone, a small dormant volcano that last erupted about 7,200 years ago.

Scientists monitored the situation and a group of experts, some from the U.S. Geological Survey and the University of Washington, met Tuesday to look at the data collected so far.

They agreed that the micro-quakes were likely caused by magma, or liquid rock, deep in the Earth's crust in the region around the Nazko Cone, a small dormant volcano west of Quesnel.

They said the intensity had levelled off to an ongoing series of micro-quakes — about 50 to 60 per day — with a magnitude of 1.0 to 1.5, but that the risk of a volcanic eruption remained low.

Earthquakes of less than 3.0 magnitude are generally not felt by people, but can be detected by seismographs.

The Nazko Cone is considered to be the easternmost volcano in the Anahim Volcanic Belt, a 600-kilometre-long line of volcanic activity that runs from the northern tip of Vancouver Island to the Quesnel area.