CBC Digital Archives

Earthquakes and Tsunamis: Predicting the unpredictable

Beneath our feet, Canada is constantly atremble. Earthquakes shake the country about 2,500 times per year, most too small to feel. But occasionally, and without warning, the earth's crust below Canada buckles and spasms to frightening effect. More dangerous are the tsunamis that such quakes can cause. CBC Archives looks back at notable Canadian quakes, fears about "the big one" predicted for the West Coast and scientists' efforts to better understand the threat from below.

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.
• 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. See a clip about the project's launch here.
Medium: Television
Program: The Journal
Broadcast Date: Jan. 13, 1986
Guest(s): Rich Lifty
Reporter: Jerry Thompson
Duration: 5:01

Last updated: October 11, 2012

Page consulted on December 6, 2013

All Clips from this Topic

Related Content

1964: B.C.'s tsunami disaster

Residents of Port Alberni, B.C., pick up the pieces following 1964's massive tsunami.

Year 2000 predictions by children

Elementary students give their predictions for the 21st century.

Psychics predict the future as year 2000 appr...

An astrologer and a clairvoyant look at the new millennium.

The earthquake threat in British Columbia

What causes earthquakes? And should people on the West Coast be worried?

Earthquakes and Tsunamis: Quebec shaken

The biggest earthquake to hit eastern North America in half a century strikes in Quebec's quak...