Was that an earthquake or a Taylor Swift concert? Swifties give new meaning to “shake it off”

Like Taylor Swift, her fans are apparently lightnin’ on their feet. When thousands of Swifties shook it off last August as the pop star’s record-breaking “Eras Tour” touched down at SoFi Stadium in Inglewood, Calif., they caused earthquake-esque activity, according to a study conducted by researchers at Caltech and UCLA. “It’s been well known that concerts make these harmonic signals and it’s not always been clear as to why,” Caltech seismologist Gabrielle Tepp, who oversaw the study, told The Los Angeles Times. “This was one thing that we were kind of interested in seeing if we could really nail down what was causing it.”

The study, titled, “Shake to the Beat: Exploring the Seismic Signals and Stadium Response of Concerts and Music Fans,” centered on Swift’s Aug. 5 performance, which was reportedly attended by 70,000 Swifties. Tepp and other researchers were able to trace the “seismic signature” of each song Swift performed, with “Shake It Off” resulting in the “largest local magnitude of 0.851.” But what, specifically, was the cause of the seismic activity? It was likely the “dancing and jumping motions” of the singer’s own fans — not SoFi’s audio system.

“It turns out jumping is very effective at creating these harmonic signals. The stronger or the more people you have jumping, the more energy is going into [the ground],” Tepp added. “I would definitely say for the stronger songs, you probably have a lot more people excited, a lot more people jumping around.”

This isn’t the first time we’ve heard rumblings of a so-called “Swift Quake.” Last July, following Swift’s two-night stay at Seattle’s Lumen Field, a geology professor from Western Washington University determined that the concerts “caused seismic activity equivalent of a 2.3 magnitude earthquake.”