When sports fans get really excited it seems like there's an earthquake – and scientists don't want to let that phenomenon go to waste. As the American football teams the Seahawks and the Green Bay Packers faced off in Seattle on the weekend, University of Washington seismologists with the Pacific Northwest Seismic Network (PNSN) planted seismographs to study the fanmade "earthquake" caused as a way of testing new sensors and software.
If you've ever spent any time in Washington State, you'll know that it's gone a bit mad ever since the Seahawks won the Superbowl last year. Seahawk flags fly regularly from pickup trucks, "12th Man" banners fly from balconies, and you can tell when a game is scheduled because the bakeries start selling cakes and pastries frosted in the team colors – which is unfortunate because they're rather unappetizing shades of green and blue.
The fans' enthusiasm has become notoriously boisterous, so as the Seahawks squared off on Sunday against the Green Bay Packers at the Seahawk's home stadium in Seattle for the 2015 NFL playoff, it isn't surprising that scientists were keen to harness all that energy for science. In this case, it was to test new earthquake sensors and communications systems for warning the public.
Seismographs are a vital tool in the fight to reduce the property damage and loss of life due to earthquakes. But while great advances have been made in seismic sensors and software, testing them is a problem. That's because earthquakes aren't predictable, so it's hard to set up testing schemes.
That changed in 2011 when PNSN seismologists noticed that at the climax of a Seahawks game a nearby seismograph was picking up the vibrations caused by the excited football crowd reacting following Marshawn Lynch's touchdown run. The resulting seismograph records were dubbed the "Beast Quake."
Scientists decided to exploit the phenomenon.
Before Sunday's game, PNSN installed a series of sensors in and around the stadium, which included seismographs, the QuickShake tool for faster connections between the sensors and the internet, and new software capable of displaying seismic vibrations inside three seconds and five to ten times faster than previous versions. These don't record the noise made by the crowd, but rather how their jumping and stomping make the stadium rock. Since winning Sunday's game meant the Seahawks would have a shot at taking the Superbowl for the second year in a row, the crowd would be particularly excited, and the scientists confessed to rooting for a Seahawks win.
In addition, two PNSN team members were stationed in the stadium to look for explanations for previously recorded odd spikes, such as the those seen during television commercials between plays that PNSN calls "dance quakes."
The scientists point out that Sunday's Beast Quake wasn't a true earthquake, which are caused by sudden, near instantaneous slips down in the Earth's crust while the fans' stomping was on the surface and went on for several seconds or minutes at a time.
The hope is that tests like this will one day lead to a network of properly calibrated sensors with which it will be possible to provide the public with earthquake warnings ranging from ten seconds to ten minutes before impact. Though seconds may not seem like much, it is often sufficient time to reach shelter, switch off electrics, or close gas mains.
Another aspect of the test was that it gave PNSN a chance to practice using social media tools.
The results of the test were better than anticipated with PNSN tweeting "TOUCHDOWN @Seahawks!!! @DangeRussWilson to @chopchop_15 for a seismic signal close to a real earthquake! #QuickShake." This was accompanied by an image of the resulting seismograph.
“We’re mostly interested in the speed and the reliability of the communications,” says John Vidale, a UW professor of Earth and space sciences and director of the seismic network. “It’s hard to simulate thousands of people using this [social media] tool all at once. When we can get a lot of people looking, we can see problems that we’d encounter during an actual earthquake.”
One practical upshot of the experiment was that attentive fans got a tip off about big plays because the PNSN website showing the sensor readouts gave “Early Football Rowdiness Warnings” that weren't subject to the 10-second delay that television broadcasters use.