This Sunday gone, Mexico and Germany’s soccer teams were engaging in battle on the pitch when the former’s Hirving Lozano scored the only goal of the match. Understandably, plenty of people in Mexico City, their eyes glued to giant television screens in squares and public parks, went bananas.
According to SIMMSA, the seismological branch of the country’s Institute of Geological and Atmospheric Research, this jubilance was picked up on at least two seismometers within the city. The group’s Twitter account explained that this shaking was caused “possibly by massive jumps” during the goal.
This, by the way, is not technically a real earthquake. That requires tectonic movements involving faults, which would have generated a true seismic wave. Real earthquakes, even smaller ones, are also incredibly energetic compared to anything we can muster, and have their own clear seismic signals.
As ever, although we don’t wish to dampen the scale of the excitement of soccer fans, this recent event in Mexico was in fact incredibly tiny.
“Such events are not very large at all; only sensitive and generally close seismographic equipment can detect the effects of the crowds,” the SIMMSA blog entry explains. “The event is not noticeable to the general population.”
These artificial earthquakes, or pseudoquakes, are actually more common than you think, pretty much because seismometers are necessarily highly sensitive.
Back in November 2017, a tremor-like event shook the city of Lima. It registered as a 1.0M event, which was enough for the Sismo Detector app on people’s phones to send out an earthquake alert. According to Sismologia Chile – which also detected this weekend's Mexico pseudoquake – this was caused by “the emotion of Peruvians” who jumped up and down when Peru’s Jefferson Farfan broke the 0-0 stalemate with New Zealand.
The creator of the Sismo Detector app suggested that this jumping wobbled the accelerometer inside people’s smartphones, which is what triggered the false earthquake alert. At the same time, the Geophysical Institute of Peru confirmed that there was a vibration “propagated by the ground caused by the euphoric jumps in unison” of the 50,000 or so fans at the capital’s National Stadium, which hosted the game.
Compared to people, though, meteors have us beat. Back in January of this very year, a smallish meteor exploded in the skies above Michigan. The subsequent shockwave slammed into the ground, which registered as a 2.0M tremor on seismometers. The larger Chelyabinsk event in 2013 over Russia, which released the same energy as 500,000 tons of TNT exploding, came in as a 2.7M event.
Even hurricanes can give seismographs a bit of a fake-out. 2017’s Hurricane Irma’s windy fury, for example, was picked up on instruments as it plowed toward the Lesser Antilles.
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