Fans attending recent concerts by Metallica and Iron Maiden in Athens created measurable seismic activity, with Metallica supporters producing the strongest tremors, according to Greece’s National Observatory.
Researchers from the Institute of Geodynamics analysed data collected by earthquake-monitoring equipment installed at the Olympic Stadium and found that crowd movements at both concerts generated micro-quakes.
The study concluded that Metallica fans were not only more numerous but also more energetic, producing seismic activity equivalent to a magnitude 1.5 earthquake during the performance of the song Moth Into Flame.
By comparison, Iron Maiden concertgoers generated tremors equivalent to a magnitude 0.9 earthquake during Killers.
The researchers also examined crowd activity during the EuroLeague basketball final held near the stadium on May 24. While supporters generated measurable vibrations, the seismic activity was lower than that recorded at Iron Maiden’s concert.
“The results highlight how seismology can record not only natural phenomena but also the effect of human activity on the environment,” the institute said.
“The two concerts served as a large-scale natural laboratory where… the Geodynamic Institute was able to study how the collective movement, rhythm and enthusiasm of tens of thousands of fans can be converted into measurable seismic waves.”
Around 80,000 people attended Metallica’s Athens concert on May 9, approximately 30,000 more than the crowd at Iron Maiden’s performance two weeks later.
Researchers said the findings demonstrate how large gatherings can produce detectable seismic signals, offering scientists a unique opportunity to study the effects of human activity through earthquake-monitoring technology.