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BY DAVID COGLON
Freelance Writer
Those attending the 2003 Honorary were treated to a vivid
history of earthquakes and tsunamis on the West Coast, filled
with archival photos, eyewitness accounts and film footage.
Dr. Garry Rogers, a research scientist at the Geological
Survey of Canada’s office in Sidney, B.C., explored
the causes behind some of Western Canada’s most damaging
quakes — including the mysterious killer that wiped
out an Aboriginal village in the 1700s on Vancouver Island
and Canada’s largest recorded earthquake, measuring
8.1, that shook the Queen Charlotte Islands in 1949.
Dr. Bernard, director of the Pacific Marine Environmental
Laboratory of the National Oceanic and Atmospheric Administration
in Seattle, Washington, followed by discussing the natural
forces that lead to tsunamis.
Japanese for “harbour wave,” the word “tsunami” refers
to a series of waves that can build up in height — sometimes
up to 30 metres — crossing the ocean to wreak havoc
on coastal communities. They are triggered by large disturbances
of the sea surface, usually by earthquakes or landslides.
“They travel about the speed of a jet in the open
ocean,” said Dr. Bernard. “And as they come ashore,
the energy is confined to a smaller volume of water, pushing
up a tidal wave. You can have huge waves hitting shorelines
thousands of miles away from each other. A tsunami keeps
on destroying as long as the energy propagates.”
According to Dr. Rogers and Dr. Bernard, earthquakes and
tsunamis are bad news-good news stories: They have the power
to inflict devastating destruction on people and communities.
But thanks to advances in science and engineering, we’re
learning how to build more earthquake-resistant structures
and how to better detect and anticipate tsunamis.
“If engineers know and understand the ground-shaking
forces, they can design buildings that are very resistant.” said
Dr. Rogers, who is a member of the Canadian National Committee
on Earthquake Engineering. “Most of the structures
we’re building today are going to resist the next earthquakes.”
Dr. Bernard echoed the importance of preparing for extreme
natural events.
Over the last seven years, the U.S. oceanographer has been
actively involved in developing a tsunami hazards identification
program in California. The program uses signage to identify
hazard zones on beaches and coastlines and provide vacuation
routes to safe areas, usually high ground.
“This program will increase our ability to withstand
the next tsunamis. This is an unusual program in that it
has started not after a major catastrophe — but before,” said
Dr. Bernard.
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