September 19, 2005

SILENT, BUT DEADLY? (via Robert Schwartz):

Tremors may mean 'Big One' on its way (MARK HUME, September 14, 2005, Globe and Mail)

A silent tectonic event, so powerful it has shifted southern Vancouver Island out to sea, but so subtle nobody has felt a thing, is slowly unfolding on the West Coast.Scientists who are tracking the event with sensitive seismographs and earth orbiting satellites warn it could be a trigger for a massive earthquake -- some time, maybe soon. But they are quick to add that the imperceptible tremors emanating from deep beneath the surface are sending signals scientists are not yet able to comprehend fully and "the Big One" might yet be 200 years off. What they do know is that the earth is moving this week on the West Coast as two massive tectonic plates slip past each other.

"Southern Vancouver Island is sort of sliding towards the west right now. We're moving towards Japan," said John Cassidy, a seismologist with Natural Resource Canada at the Pacific Geoscience Centre near Sidney, B.C. "It's a very small amount. We've moved about three millimetres to the west over the past couple of days."

The event, known as an episodic tremor and slip, is a predictable, cyclical phenomenon that is adding pressure to a zone where the Juan de Fuca Plate and the North American Plate are locked, just off Vancouver Island. While the two plates are slipping in some areas, in another they remained locked. That locked zone is where the next megathrust earthquake is expected to come from when it suddenly releases. Mr. Cassidy said a slip event occurs every 14 months, and when it does, scientists believe the chance of an earthquake the size that triggered the Asia tsunamis increases. One researcher has likened the event to going up a step on a staircase, at the top of which sits a megathrust earthquake. But nobody knows where the top is or where we are on the staircase.

The geological record on the West Coast has shown that megathrust earthquakes occur roughly once every 500 years. The last one struck on Jan. 26, 1700, which leaves a window of possibility 200 years wide.

"We know there will be another megathrust earthquake, but we don't know when," Mr. Cassidy said.

But everyone's prepared, right?

Posted by Orrin Judd at September 19, 2005 6:09 AM

Prepared to blame George Bush and the GOP, yes they are.

Posted by: jim hamlen at September 19, 2005 10:50 AM

Yep. New Orleans, Bay Area, Puget Sound, SoCal basin -- its obvious Bush and Karl Rove are using their black ops natural disaster machine to target heavily Democratic areas of the country, while a tornado hasn't hit a Red State since the fall of 2000...

Posted by: John at September 19, 2005 10:58 AM

Actually, I heard that Bush, Cheney, Rove & co. were all in town recently making sure that all the bridges and buildings that are supposed to collapse are ready to go. Bush himself was drilling holes in the Alaskan Way Viaduct to make sure it's properly weakened.

A little planning ahead goes a long way.

Posted by: Raoul Ortega at September 19, 2005 6:28 PM