Earthquakes shake old British Columbia Volcano back to life*

Larry Pynn , CanWest News Service; Vancouver Sun
Published: Tuesday, October 16, 2007

VANCOUVER - Scientists are headed today to a remote area in the B.C.
Interior to install seismic equipment and determine whether a "swarm" of
small earthquakes is evidence of a forthcoming burst of molten lava -
the first volcanic activity in Canada in almost two centuries.

"It's pretty exciting to see this," said John Cassidy, an earthquake
seismologist with Natural Resources Canada. "The earthquakes are
continuing, even today. We should have some answers soon."

Existing seismic equipment at Thunder Mountain south of where the
earthquakes are happening - about 100 kilometres west of Quesnel, B.C. -
began recording earthquake activity on Oct. 10.

Since then, there have been more than 100 small earthquakes, most of
them magnitude 1.0 or less on the Richter scale but some as big as 3.1
or 3.2, emanating from 25 kilometres below the earth's surface.

The activity is located about 20 kilometres west of Nazko Cone, which
last erupted about 7,200 years ago.

The cone is now being mined by Lightweight Advanced Volcanic Aggregates
Inc. for its basalt and black pumice - up to 50,000 tonnes a year, used
as fill for construction, concrete blocks, barbecue rock and landscaping.

"The lava king, that's what they call me," company president Brian Wear
said.

He said his employees feel small earthquakes from time to time at the
site, but not recently due to the depth at which they are occurring.

Wear said doesn't believe a lava flow is forthcoming, but admitted one
would be interesting to watch.

Federal volcanologist Catherine Hickson said that if the latest
earthquakes lead to volcano activity, one might expect "fire
fountaining," with lava expelled up to 100 metres in the air.

Hickson has travelled around the world to view volcanic activity, and
said she's a little excited at the prospect of seeing lava in her own
backyard. The lava might be expected to flow five to 10 kilometres, and
the ash spread 10 to 20 kilometres.

No major population centres are threatened by such an eruption. But Wear
said there is active logging and ranching in the region.

Hickson said the most recent volcanic eruption in Canada is estimated to
have happened around 1830 to 1850 in northwestern B.C.

Even if lava is on its way, it could take weeks or months to reach the
surface, Cassidy said.
*
 Earthquakes recorded near dormant volcano*

by MARK NIELSEN

Seismologists are keeping a close eye on a spot in the vicinity of a
dormant volcano about 150 km. southwest of Prince George where eight
small earthquakes have been recorded over two days.

The earthquakes, the first of which was recorded on Tuesday at about
7:30 p.m. and the latest on Thursday at about 8 p.m., occured about 21
km. west of the Nazko Cone, a small tree-covered volcano that last
erupted about 7,200 years ago.

The earthquakes ranged from 2.8 to 3.2 on the Richter scale -- strong
enough that anyone in the immediate area would have felt them -- and
appeared to be 20 to 25 km. below the earth's surface.

John Cassidy, a seismologist at Natural Resources Canada's Earthquake
Canada office in Sidney, B.C. said the depth is enough to rule out
hydro-thermal but it's still up in the air as to whether the cause is
tectonic shifts or volcanic activity.

"If it is volcanic there are certain characteristics that we would
expect, there's a tremor-like character to it," Cassidy said. "And so
we'll be looking for the types of events that we see beneath volcanoes
and we'll be looking to see if they're getting closer to the surface or
if they're migrating at all."

Catherine Hickson, a volcanologist at the Geological Survey of Canada
office in Vancouver is also keeping an eye on the events, saying 25 km.
is about the depth magma would be expected to pool and make its way to
the earth's surface.

If it does turn out to be volcanic activity, she doubts it will become
another Mount St. Helen but rather a Hawaii-style volcano characterized
by a "fire fountain" that sends globs of lava about 100 metres into the air.

"We're not talking about an injection of tonnes of ash many kilometres
into the air like the 1980 Mount St. Helen eruption or the 1931 Mount
Pinatubo eruption," Hickson said. "We're talking about something very
small, relatively localized that should have a fairly limited
impact...but it'll be extremely exciting."

Like the lava flows on Hawaii's Big Island, she said it could even be a
tourist attraction but warned some noxious gases will accompany the
sight in the form of carbon dioxide and sulphur dioxide.

Staff are in the process of contacting hunting and fishing lodges in the
area to see if anyone there felt anything, Hickson said.

Located about 75 km. west of Quesnel, much of the Nazko Cone been taken
away since mining of the site for red industrial aggregate for
landscaping began in the early 1990s. It's the easternmost volcano on
the Anahim volcanic belt, which stretches 600 km. westward to just north
of Vancouver Island.

Cassidy said the earthquakes recorded there pale in comparison to the
one Prince George felt in March, 1986. Reaching 5.4 on the Richter sale
it was about 200 times stronger, he said, enough to damage some
chimneys. Its epicentre was about 50 kilometres northeast of the city.

Cassidy said there's never been a magnitude 3.0 earthquake recorded in
the Nechako Basin in the nearly 50 years detection equipment has been in
place.