Beast Quake (Taylor’s Version): Analysis of Seismic Signals Recorded during Two Taylor Swift Concerts in Seattle, July 2023

Taylor Swift’s concerts at Lumen Field in Seattle, Washington, USA, on 22 and 23 July 2023 were detected by an accelerometer located proximal to the stadium. The signals were nearly identical over the two nights, consistent with a repeated setlist. Ground shaking is recorded in two frequency bands: broadband energy between 30 and 80 Hz, and harmonic low frequencies between 1 and 8 Hz. Discrete songs are clearly visible within the data, with narrow-band low-frequency signals matching the published tempo of each song. Signals recorded during the sound check contain little to no low-frequency energy, suggesting that low-frequency energy is associated with the synchronous motion of a dancing crowd. High-frequency energy is observed only during songs that include a full band, as opposed to solo acoustic performances by Swift. Video data provided by citizen scientists at the concerts allow us to correlate changes in seismic amplitude with observations of crowd motion. The synchronized motion of 72,000 fans created sustained energy that exceeded the iconic “Beast Quake” in 2011.