Football vs. NASCAR: Which Fans Rock Hardest?

By Becky Oskin
Senior Writer

NASCAR has loud fans and even louder engines, but can it beat the "Beast Quake?" 

Football, NASCAR and their rowdy, roaring crowds faced off in a head-to-head battle this year to see which sport hits highest on the seismic charts, scientists reported Dec. 18 at the American Geophysical Union's annual meeting in San Francisco. 

Seattle Seahawks football fans have stomped their way to several "earthquakes," shaking the football stadium so hard that nearby seismometers register tremors. . . 

Not to be outdone, this year the Texas Motor Speedway asked seismic experts from Southern Methodist University in Dallas to record the Duck Commander 500 race. It's a typical NASCAR race, with 43 stock cars roaring around a 1.5-mile (2.4 kilometers) track and twice the number of fans as a Seahawks game. 

"The owner wanted to be able to say his race had larger ground motions than the Seattle Seahawks," joked Brian Stump, a seismologist at Southern Methodist University and co-leader of the project. More seriously, Stump and other scientists are interested in monitoring large crowds with seismic and acoustic signals transmitted through the earth and the air. And large structures such as stadiums, bridges and tunnels have natural frequencies that can change when something is amiss, such as unwanted cracks. As such, monitoring the vibrations is a way to detect unseen damage to these imposing structures. 

"We're thinking about how we can use these techniques to monitor a number of sources," Stump said. . . 

The higher frequencies detected at the Texas race can't travel far through the earth, so little in the way of race noise was picked outside the speedway. The strongest signal that appeared on the researchers' distant instruments was from a magnitude-4.5 earthquake in Oklahoma that rattled the stadium during the study, though it was not strong enough to be felt by race fans in Texas. 

Inside the Speedway, the Texas researchers and their instruments could also "see" weekend fireworks, two helicopters tracking the race, machines drying the track after a Sunday rain, a fiery crash, and green flag and yellow flag laps. Stump said the overall experiment was a great success. 

"We can directly relate the recordings to things going on in the race," Stump said. "Seeing the physics of the race itself and pairing it with the waveforms was a great educational experience."

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