An earthquake isn’t an equal-opportunity shaker.
So to determine how a quake’s power differs across the Puget Sound region, scientists are setting up sensitive monitoring equipment in someplace solid, such as a house basement, to track that power as part of the NetQuakes project.
A handful of seismographs have been installed in Renton and Kent, where soils, topography and the ground rupture itself all play a role in how a quake affects buildings.
“We discovered in the Nisqually quake and other quakes around the world that ground motion can vary pretty dramatically from neighborhood to neighborhood,” said Bill Steele, Seismology Lab coordinator for the Pacific Northwest Seismograph Network.
Monitoring of the State Route 167 corridor has been emphasized, because of a lack of monitoring stations to track ground motion, he said.
There were some ground-motion stations in 2001 that monitored the Nisqually quake, but not in Renton and Kent, he said. In that quake, a production building at the Boeing plant in Renton was red-tagged, he said. But scientists didn’t have a direct measurement of the ground motion there.
“We want to begin filling in so that doesn’t happen again,” he said.
The network, run out of the UW Seismology Lab, is looking for volunteers in the Auburn area, where there are currently no NetQuakes seismographs.
The equipment uses a wireless router to send the measurements to a U.S. Geological Survey facility in California, then almost immediately to the UW lab in Seattle. The USGS oversees the NetQuakes program nationally and provides the equipment.
Ideally, scientists would like one of the strong-motion monitors every kilometer or roughly every two-thirds of a mile in the urban Puget Sound region. A national plan calls for 600 strong-motion monitors in then Puget Sound region; right now there are about 100.
“We have a long ways to go,” Steele said. Each year the network is allocated a certain number of seismographs.
NetQuakes continues to look for volunteers to host the small monitoring equipment, which is anchored to something solid in a house or business.
“The idea is to involve citizens in the science,” he said.
Interest in the science is what drew Sarah Markham of Renton to volunteer to host one of a seismograph in the basement of her north Renton home.
“I could do that,” she said, after learning about the program.
Her home is not far from Lake Washington and Boeing’s Renton production plant. Her location helps fill in the gap that Steele mentioned near the Boeing plant.
The wireless router that sends data to the USGS sits in her living room. The blue seismograph is anchored to the basement floor next to the furnace in her home, built in 1920.
Markham is a fairly recent resident of Renton. Her family has deep roots in Illwaco, on the Washington coast. There the concern was a tsunami from the Pacific. She has never experienced an earthquake.
In 1986, her family fled to higher ground after an Alaska quake triggered a tsunami warning across the Pacific.
Several factors are considered in locating a seismograph. Ideally, it’s a single-family dwelling with a concrete slab lying directly on the ground and not a deep basement.
The geographic location is important, including the floor of a valley or a ridge, so scientists can understand the impact of a quake on different structures.
“We can’t predict earthquakes,” Steele said, but the network of seismographs help scientists better understand the effects of a quake.
HOW TO VOLUNTEER
The NetQuakes project
The NetQuakes project is operated in the Northwest by the Pacific Northwest Seismic Network at the University of Washington Seismology Lab. The network is taking applications for volunteers to host a seismograph, especially in Auburn. Information about NetQuakes and volunteering is available at the U.S. Geological Service website at http://earthquake.usgs.gov/monitoring/netquakes/
