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Seismologists predict the unpredictable

The Story

Seismologists have California wired. Electronic sensors record every twitch, thrust and tremor on each side of the San Andreas fault. Decades of such data have helped scientists predict where major quakes will strike in the United States and Canada. But they remain in the dark when it comes to the all-important question of forecasting when, in the short term, the earth's crust will spasm, we hear in this CBC Television report. "That has turned out to be a very difficult problem," a researcher says. The experts are focusing their attention on Parkfield, a California farming community that straddles a volatile fault line. Parkfield shakes violently every 21 years or so and with predictable force. Seismologists hope that, if they can spot telltale signals of impending tremors, the tricky science of predicting earthquakes could get a whole lot easier.

Medium: Television
Program: The Journal
Broadcast Date: Jan. 13, 1986
Guest(s): Rich Lifty
Reporter: Jerry Thompson
Duration: 5:01

Did You know?

• When this clip aired in 1986, Parkfield, Calif., population 37, had experienced its last major earthquake 20 years earlier and was due for another. The quake struck the morning of Sept. 28, 2004. It was a magnitude 6 and similar in characteristics to previous ones. The quake caused damage in central California but no reported injuries. Prior to 1966, Parkfield had experienced quakes in 1934, 1922, 1901, 1881 and 1857.

• The business of predicting, with any certainty, when an earthquake will strike remains a difficult one. No Canadian government agency offers short-term predictions. The narrowest time frame that scientists at Natural Resources Canada will offer is for the West Coast. They say a major quake is likely to strike there any time within the next 200 years but caution that the forecast is inexact.

• People have for centuries believed that animals possess an innate ability to sense impending earthquakes. Such observations date back to 373 BC when Greek historians said rats, snakes and weasels fled the city of Helice days before a devastating quake. Today, cats and dogs are often reported to have displayed pre-tremor agitation. Modern studies have been inconclusive. The phenomenon was explored in a 1978 report on the CBC Radio program Sunday Morning.

• Earthquake forecasting is expected to get a boost from Project Neptune. The $300 million U.S.-Canada project will place 3,000 kilometres of fibre-optic cable on the Juan de Fuca tectonic plate. That will, among other things, provide information about the plate's movement -- a major source of earthquakes. Project Neptune should also give up to 60 seconds warning of major quakes in the area -- enough notice to shut down West Coast natural gas lines. 



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