Before last weekend’s game, network scientists set up two near real-time seismic monitors at CenturyLink to augment data from a third seismograph about a block away. Together they provided a scientific measurement of the energy of Seahawks’ “12th man” – the fans – and the most difficult real-life test for the recently redesigned website, , as fans inundated the site.

“I was watching the traffic from the CenturyLink Field press box and saw the web slow way down as tens of thousands of requests for seismograms were arriving almost simultaneously,” said Jon Connolly, a seismic network software engineer. “I was able to tune and rebalance how the requests were managed and we learned a lot about how to reorganize some services to be ready for the next big earthquake or volcanic eruption.”

Those seismograms, dubbed “,” were so popular that Steve Malone, a 91̽»¨professor emeritus of Earth and space sciences, had to shut down his experimental “Fan-O-Meter,” which combined the three stations’ outputs in a streaming graph that was almost synchronized with the TV broadcast delay.

“Folks were getting bounced out after a few minutes or could not see the display at all when the servers became overwhelmed by the demand,” Malone said. But a private version of his software running within the seismic network turned out to be very useful for associating crowd reaction with seismic signals.

“We could tell from these signals something about what we were about to see on TV seconds later, due to the broadcast delay,” Malone said.

The seismometers picked up local traffic, trains and the stadium’s powerful heating and cooling pumps. It also picked up a strange harmonic vibration a couple of minutes after Seahawks touchdowns.

The signal from the heating and cooling pumps was so strong at one of the stations that technicians this week moved that instrument to a quieter spot near the field, and placed an additional seismograph on the third deck of the stadium.

That means the network now has four instruments ready to measure the seismic aftermath of what they expect will be another “Beast Quake” during Sunday’s game between the Seahawks and the San Francisco 49ers, which will determine which team wins the NFC championship and goes to the Super Bowl on Feb. 2 in East Rutherford, N.J.

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For more information, contact John Vidale at 310-210-2131 or vidale@uw.edu; Paul Bodin 206-257-8047 or bodin@uw.edu; or Bill Steele at 206-601-5978 or wsteele@uw.edu.

91̽»¨ seismologists this week installed two strong-motion seismometers at CenturyLink Field in Seattle to augment an existing station in recording shaking from “earthquakes” expected on Saturday during the NFC divisional game between the Seattle Seahawks and New Orleans Saints.

The Pacific Northwest Seismic Network is preparing a special website at for the game to display seismograms from all three seismic stations in near-real time, and seismologists will also be available to explain interesting signals. Seismologists also will highlight interesting signals in tweets (@PNSN1) and on Facebook (thePNSN).

Seahawks fans, collectively known as “the 12th man,” have a well-known reputation for generating noise and shaking in the stadium during games. Perhaps the best-known example occurred on Jan. 8, 2011, during a by the Seahawks Marshawn Lynch that helped Seattle defeat New Orleans in an NFC Wild Card game.

Scientists hope to record similar shaking during Saturday’s game to better understand how the stadium responds to the activity, and to measure the energy transmitted to the ground within the stadium and within the surrounding neighborhood.

The experiment provides a test of equipment that will be used to monitor aftershocks following a traditional earthquake and will provide technical training for staff of the UW-based Pacific Northwest Seismic Network.

“Because the fault ruptures that generate earthquake waves are almost always buried by miles of rocks, scientists aren’t sure about the action at the source that results in seismic shaking. In a way, the Seahawks’ 12th man provides us an opportunity to get inside the source that’s generating seismic waves,” said seismic network operations manager Paul Bodin, a 91̽»¨research associate professor of Earth and space sciences.

“While the basic mechanics are quite different – earthquakes release energy stored in rocks by frictional sliding on a fault while the fans produce energy by excited jumping in reaction to events on the field – both of those processes produce organized seismic waves that may travel long distances and have similar characteristics,” Bodin said.

“We think that it’s actually the CenturyLink stadium structure itself that acts as the organized seismic source, energized by the excited, although disorganized, crowd movement.”

The resulting seismic signals could be similar to what scientists would be able to see if they could place a sensor inside a complex geological fault system, he said.

Other scientific benefits of the work could include understanding:

• Unusual ground vibrations in an urban setting and understanding the variability in ground motions at different sites.
• The vibrational response of a large structure, helping engineers to learn about different design elements.
• How the seismic network’s website is used by the general public, and how it stands up to heavy user traffic.

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For more information, contact Vidale at 310-210-2131 or vidale@uw.edu; Bodin 206-257-8047 or bodin@uw.edu; or Bill Steele at 206-601-5978 or wsteele@uw.edu.