During a show in Auckland, New Zealand on December 13th, the Foo and 50,000 crazed fans made so much commotion and noise that they literally created tremors similar in size to a volcanic event. According to two seismic stations outside the Western Springs stadium, where the performance took place, 1.5 and 2 kilometers from the stadium, strong low frequency tremors were detected during the time of the show. Upon further inspection, the tremors highs and lows correlated exactly with the highs and lows of the show and were in comparison to that of volcanic activity.
All this information coming from New Zealand's GeoNet Blog, which recorded the geological tremors from the show.
“The concert vibrations were recorded as a semi continuous harmonic signal with a peak osculation of 3Hz, i.e. the ground was shaking 3 times per second in a nice rhythmic motion. There are lulls in the signal between the songs and peaks in signal intensity during the songs.”
Need we say more. The Foo Fighters, a.k.a. "the hardest working band in the business," are definitely rock n' fuckin' roll.