An earthquake early-warning system is being planned for the Chilliwack River Valley, and could provide alert capabilities for the wider region.
The system has the ability to provide several seconds of warning before an earthquake, which can be crucial at bridges, tunnels and on railways. It can even give surgeons time to stop surgery before shaking starts, according to a staff report given to the Fraser Valley Regional District on Feb. 13.
The detection system is to be placed at the Chilliwack River Volunteer Fire Hall, and would be "relatively small" at about 3' by 4' by 4', within an exterior metal cabinet. It will also be accompanied by a mounted GPS antenna.
It's all part of Natural Resources Canada work to develop an Earthquake Early Warning (EEW) system for at-risk regions in Canada. The report explains that the system will use a "specially designed network of seismic sensors to provide a few seconds to tens of seconds of warning in the event of a major earthquake, allowing protective actions to be taken."
The report also explains the difference between seismic waves and how the system works, from the first detection to the public alerts.
"The EEW seismic sensors detect the first energy to radiate from an earthquake, the P-waves, which rarely causes damage," the report states. "The sensors transmit this information to data centres where a computer calculates the earthquake's location
and magnitude, and the expected ground shaking across the region.
"This method can provide warning before the arrival of secondary S-waves, which brings the strong shaking that causes most of the
damage."
Patti Macahonic, the director for the Chilliwack River Valley's electoral area (E), called the impending system a "great public service" and thanked staff for their work with Natural Resources Canada.
Alerts would be sent out via national alerting systems, which can give people crucial time to prepare for potential shaking and mitigate risks. That can mean diverting planes from landing, stopping traffic at bridges and tunnels, halting trains, allowing surgeons to stop surgery, or workers to close gas valves.
The staff report said the EEW station will become an "integral part of a much larger early detection system for earthquakes that may impact the area. The resulting licence will provide minimal financial aid to the hall but will serve an important function within the community at large."
Many people in Chilliwack felt the effects of a 5.1-magnitude earthquake that was centred near Pender Harbour Feb. 21.
