Updated Earthquake Maps Show Fault Lines Run into BC
April 24, 2008
CTV British Columbia - Vancouver, Canada
Two British Columbia fault lines running south of Abbotsford and south of Victoria could potentially cause earthquakes measuring 6.8 on the Richter scale, according to a new study released by U.S. seismologists.
Image: The U.S. Geological Survey released a study showing the discovery of two earthquake fault lines that run into B.C., April 2008.
Updated seismic hazard maps from the U.S. Geological Survey show the newly discovered, shallow fault lines south of Victoria, along the Olympic peninsula, and in northwest Washington State, south of Abbotsford, could cause earthquakes that would result in severe damage potentially costing billions of dollars.
The hazard maps, a result of decades of research, show that a quake of such magnitude could cause severe damage to the structure of buildings and infrastructure.
Research scientist Dr. John Cassidy with Natural Resources Canada said the new information is valuable in terms of safety standards.
"Some of these new studies that are underway, looking for faults, in a few different ways, gives us an idea of what we might expect in the future, in terms of where, how often and how big they may occur."
The discovery of the faults could help engineers design the structure of buildings to accommodate risk, he said.
"The discovery of some faults has clearly changed the hazard maps in the region, and the Seattle fault that was discovered a number of years ago was a really good example (of that)," he said. "A major fault running right through the city of Seattle clearly changed the hazard maps for that reason."
A 6.8 magnitude earthquake in Seattle in 2001 resulted in damaged buildings, cracked roads and bridges, and ruptured pipes.
But Cassidy stressed so-called 'big' earthquakes, of about magnitude 7 or higher, are very rare -- occurring about only once every 1,000 years.
"(This study) doesn't change our big picture of immediate earthquake hazards because they're quite rare earthquakes, they're quite rare events," he said.
Vancouver Island experienced quakes of that size in 1918 and 1946.
But Canada's national building code has accounted for an earthquake risk of that magnitude, he said, and would be revised accordingly if necessary.
The provincial government will launch its annual Emergency Preparedness Week on May 4, 2008, and various jurisdictions in the Lower Mainland will hold corresponding programs.
Basic emergency kit items:
* Water: two litres per person
* Food: that won't spoil, ie: canned food, energy bars, dried foods
* Manual can opener
* Flashlight and batteries
* Battery-powered or wind-up radio
* First aid kit
* Special needs items: medicines, baby formulas or disability equipment
* Extra keys: for your car and house
* Cash: include smaller bills, travellers cheques and pocket change
* Copy of an emergency plan