We Will Rock You: Noisy and Quiet Times Around the Michigan Stadium

Abstract:

A RaspberryShake seismometer (R208E) was installed in 2018 to measure audience responses during home football games of the Michigan Wolverines in Ann Arbor (MichiganShake, https://ben.earth.lsa.umich.edu/seismo/michiganshake.html). Perhaps unsurprisingly, touchdowns by the home team create a lot more activity than those by the visiting teams, amplified by the home team’s familiar fight song. Songs played over the football stadium sound system during breaks in play result in the strongest signal. Particularly anthems by Queen (We will Rock You) and The Killers (Mr Brightside) were able to move the crowd in unison; popular stadium ballads, like Journey’s Don’t Stop Believing, produced mostly vocal impact. Nearby RaspberryShake seismometers on campus (R10DC; 1.7 km away) and residential (R12C1; 6 km away) show no effect of game moments or singalongs.

Michigan’s 23 March 2020 lockdown order in response to the COVID19 pandemic provided a unique opportunity to measure societal noise as a function of location and behavior from this minicluster of instruments. The greatest drop in signal, >60%, is measured on central campus, where buildings were closed. The Michigan Stadium unit shows less impact, ~30% reduction, reflecting its location at a busy intersection of main roads in the city. The residential unit shows only modest decrease over the same period. A low-noise, nearby broadband seismometer (AAM; 8.5 km away), located away from city noise, shows ~50% decrease in daytime noise, mostly reflecting reduced highway traffic in the area. A fourth RaspberryShake station at Michigan’s field station near Jackson, WY (R2FF2) shows no appreciable change over the time period, reflecting its remote setting. The gradual loosening of stay-at-home rules by late May is recorded by a similar rise in societal seismic noise to levels before the lockdown.