As the countdown to a major earthquake that researchers expect to hit the Pacific Northwest continues, local utilities are taking steps to prevent as much damage as possible.
The last time the region was hit by a mega-quake was in the 1700s, but Northeast Sammamish Sewer and Water District general manager Laura Keough said they installed an automatic pump-shutoff station to help avoid even greater damages. Researchers are expecting that another 9.0 magnitude earthquake is coming, but they don’t know when.
“The area is prone to earthquakes, the big one is coming,” she said.
The automatic shutoff system was installed at the Crest Reservoir treatment and pump station in Sammamish. The well-fed system holds around 500,000 gallons of water in the facility which if not shut off could empty during an earthquake when pipes break.
Bill Steele is the director of outreach at the University of Washington’s Pacific Northwest Seismic Network with which the pump shutoff is integrated. When an earthquake starts, it sends out two types of vibrations. The first are fast and minor and travel faster through rock than air.
“It carries a lot of information about the earthquake but not much damage,” Steele said.
Seismographs pick up these signals and send a warning to the Seismic Network monitors which in turn are sent out as a warning and shutoff command to the pump station. Computers at the pump station blast a warning siren over speakers and employees receive phone calls telling them the earthquake is on the way.
The powerful, damaging earthquake waves follow the first waves and often rupture pipes and wires, which if not for the automatic shutoff could drain the reservoir and start electrical fires which would ruin expensive equipment.
A demonstration of the system on June 10 simulated a 7.5 magnitude earthquake from the Olympia area. The alarms went off around 30 seconds before the shaking would have started and the pumps shut down a full 10 seconds ahead of the simulated earthquake.
The system is the first of its kind in the Pacific Northwest and cost around $10,000 but can run up to $50,000 per facility. Keough said they are planning to expand it across the water district.
Michele Campbell, associate director for RH2 Engineering which designed the system, said the pump system is the first in a pilot program.
“We needed a partner to really step up and help us pilot the program,” she said.
The spectre of the Big One, a powerful and likely devastating earthquake along or off the U.S. West Coast has been in the news since an article ran on it in The New Yorker in 2015. Since then, municipalities have been working to find ways to minimize the anticipated damage when the Cascida Subduction does rupture.
The UW last October simulated how a 9.0 earthquake would shakedown in the Pacific Northwest. The Juan du Fuca oceanic plate is slowly moving beneath the North American plat which will eventually generate a massive earthquake and tsunami. The last major earthquake happened in 1700 and it repeats itself roughly every 500 years. Researchers are expecting the shaking to last around 100 seconds, or four times longer than the major 2001 Nisqually earthquake.