At 9.04 pm India time Sunday, just after Mexican winger Hirving Lozano scored the goal that would upset Germany in the World Cup, seismic sensors in two boroughs of Mexico City picked up a small earthquake. The Department of Seismology and Volcanism at the Institute of Geological and Atmospheric Investigations said it was “possibly because of mass jumping” by ecstatic fans.
The “earthquake” soon became a global story, triggering astonishment and scepticism. In its report headlined ‘Did Mexico’s Revelry in World Cup Win Over Germany Cause an Earthquake?’, The New York Times referred to a report in the Spanish daily El País, which quoted Arturo Iglesias, an investigator with the Institute of Geophysics at the National Autonomous University of Mexico, as saying that “the scattered activity of fans” could not trigger an earthquake.
The Institute of Geological and Atmospheric Investigations, however, had made it clear that the earthquake was “artificial”. “Artificial quake in Mexico City due to celebration of goal by the Mexican team in the game against Germany during the 2018 World Cup in Russia,” it had tweeted about seven hours after Lozano’s goal. And in a blog on its site, the Institute underlined, “Such events are not very big at all; only sensitive seismographic equipment (and generally nearby) can detect the effects of crowds… (Descriptions of) these events must be accompanied by the word ‘artificial’ to clearly determine that they are not geological events…” (translated from the Spanish).
Indeed, it is not unusual for earthquake-recording instruments to register vibrations from various sources nearby. Earthquakes produce a distinct, sine-wave-like waveform that can be easily identified. The vibrations produced by spectator activity in a stadium, or a low-flying helicopter, usually show up as noise in the recording instrument, said Vineet Gehlot of the Delhi-based National Centre of Seismology. Ajay Paul of the Wadia Institute of Himalayan Geology in Dehradun says one of the ways he introduces schoolchildren to the recording of earthquakes is by stomping his foot near a seismograph in his office. “It instantly produces a disturbance on the screen,” he says.
Activities like mass celebration by sports fans, or detonation of explosives, produce random and haphazard lines. Also, the strength of such signals is extremely weak, and only very sensitive seismographs can pick these up. “Artificial earthquakes” are also generated by equipment used for generating vibrations for earth exploration and seismic surveys.
However, the possibility that a large synchronised activity by celebrating fans can produce a waveform resembling one from an earthquake cannot be ruled out, Paul says. It is not entirely impossible for software to get fooled into believing that the signals actually came from an earthquake. A scientist looking at the data closely, however, would be able to tell the difference.
In fact, this is not the first time that “earthquakes” have been attributed to sports fans. It has happened even in India: during IPL matches, Gehlot says, he has noticed readings on a seismograph whenever a boundary is scored.
In 2016, the BBC reported that an “earthquake” had been created by supporters of the Leicester City football team after a last-minute winner against Norwich. A seismometer set up at the University of Leicester, 500 m from the stadium, had recorded a minor quake of magnitude 0.3. The tremor was attributed to a “sudden energy release” by fans when the goal was scored, and christened “Vardy Quake” after top-scorer and Leicester City and England striker Jamie Vardy.
“It wasn’t just a case of cheering or clapping, it was 30,000 people standing up at the same time — an awful amount of energy,” the report quoted Paul Denton, a British Geological Survey seismologist, as saying.
Again, in 1988, a seismograph in the geosciences centre of Louisiana State University picked up a blip as fans erupted in joy after the university side scored a touchdown in an American football game against the side from Auburn University. The game was dubbed “Earthquake Game”.