The Foo Fighters' recent concert in Auckland, New Zealand rocked... Literally! The movement of the fans in addition to the sound of the show itself resulted in shaking that was strong enough to get a reading from seismic equipment from up to two kilometers away.
According to GeoNet, the Auckland seismic network detected a signal akin to that of a volcanic tremor throughout the Foo Fighters' Tuesday performance.
GeoNet suggests that the shaking began during
Tenacious D's opening set and peaked once the Foo Fighters came on stage at 8:20 pm. At the highest recorded frequency the ground was "
shaking 3 times per second in a nice rhythmic motion."
"The strong correlation in time with the Foo Fighters concert and the fact it was only recorded on the 2 stations close to Western Springs assured us it was of man-made origin," Outreach Coordinator Sara Page posted to her blog. "There are lulls in the signal between the songs and peaks in signal intensity during the songs."
"The cause of the shaking is most likely the weight of the 50, 000 fans dancing, as 50, 000 fans is equal to around 5, 000 tonnes of mass moving (or moshing) on the ground for the duration of the concert... The sound system, probably contributed as well, especially the bass frequencies coupling in to the earth."
Probably Jack Black doing a knee-slide across the stage, LOL.