September 15th, 2005

Oh great! Our slip is showing…

Well, just in case we need another disaster to show FEMA’s incompetence: Slow Seismic Slip Event Underway in Pacific Northwest

An important seismic event imperceptible to humans has begun in the Pacific Northwest as predicted, according to the government agency Geological Survey of Canada.

The chance of a major earthquake is 30 times higher now for a roughly two-week period, but the odds are still remote, scientists say.

The event is called episodic tremor and slip (ETS). It involves a slow movement of the Juan de Fuca and North America tectonic plates along the Cascadia margin of southern British Columbia. Faults associated with the plates have been the sites of major earthquakes — akin to the colossal tsumani-causing quake last December in Indonesia — every 500 years or so, the geologic record shows. The last such temblor in the area struck on Jan. 26 in the year 1700.

One Response to “Oh great! Our slip is showing…”

  1. david says:

    Well, don’t pack your bags just yet. Further down the article it also says:

    “The probability of occurrence of a megathrust earthquake is about 30 times higher during this approximately two-week window, than during the rest of the 14.5 month cycle,” Cassidy told LiveScience. “Having said that, 30 times a small number is still a small number.”

    Many lay articles often make statements like “the chances of BAD EVENT happening are now X times higher”, but that’s really a meaningless statement. For example, an event that currently runs at a 50:50 chance can only get 2X higher, but that also means it’s now certain, a HUGE change. Scientists talk in terms of relative risk, but even that’s a slippery term. More info on this from my favourite science column, the Guardian’s Bad Science.

    Also, the slip began September 3, and according to the article, these slips last six to fifteen days. We’re almost out of the woods!