BC Broker Magazine - Sensor Reports Before the Wave Hits (ShakeAlarm®)
BC Broker, August 2013
One of the most frightening experiences people could ever encounter is the ground moving below them. Earthquake! What do you do first? How do you protect yourself, your family and your belongings from disaster? Will your insurance cover the imminent losses?
“When an earthquake occurs, there are two parts to the event: the P-wave and the S-wave,” says Aleriza Taale, business development manager for Weir-Jones Engineering Ltd., developers of the ShakeAlarm™ Earthquake Early Warning System (EEWS). “As soon as the earthquake is initiated somewhere below the surface, it generates a series of waves and they travel at different speeds. P-waves, or pressure waves, are significantly weaker, but they travel faster than S-waves, the destructive shock waves. The ShakeAlarm can give people a clear warning of impending earthquakes and gives them time to make their way to safety. This minimizes the loss of life or assets that can occur.”
An authentic test of the ShakeAlarm occurred in Metro Vancouver in 2009. The systems installed at the George Massey Tunnel registered after-effects of the 6.3 and 5.6 quakes that took place on Nov. 17 that year near Haida Gwaii (Queen Charlotte Islands), 720 km north of Vancouver. “The signature of the P-wave was analyzed in less than a second, and the risk analysis indicator determined that the S-wave, which had yet to arrive, would not create hazardous conditions at the tunnel,” says Taale.
After conducting meetings with several B.C. brokers, Taale has seen significant interest in the ShakeAlarm, which can mitigate losses and save customers money on their premiums with discounts offered by some brokerages. “Brokers are interested in solutions because they help clients manage their risk,” he says. “Any opportunity to mitigate loss is welcome, and the ShakeAlarm can do just that. It’s a win-win for both the brokers and the consumers.”
The benefits of an early warning system vs. a rapid response system have important differences to note. “Early warning happens prior to the ground shaking,” says Taale. “There is a time frame to shut off utilities and prepare for the actual earthquake. Rapid response is when the S-waves hit the location. It takes from one to 15 seconds to finish. The ground is already moving and you can still do some preparations, but not as much as when the early warning is given.”
Complementing the ShakeAlarm system is the ShakeMonitor™, a device that assesses how structures respond to environmental disturbances. “The ShakeMonitor gives real-time feedback on a number of factors including vibration, torsion, settlement, uplift and seismic activities,” says Taale. “Another feature of the ShakeMonitor is its ability to provide real-time damage assessment. Some buildings survive earthquakes well, but some do not. From a structural point of view it is important that the building is intact and serviceable, including elevator function. Incidences can occur up to one week post-earthquake, which is dangerous to residents or workers.”
For more information on the ShakeAlarm™ and ShakeMonitor™ go to www.weir-jones.com.