Mexico’s victory over Germany in an early World Cup game on Sunday caused quite the stir in Mexico City. At 11:35 am, when Hirving Lozano scored the game-winning goal at a match in Russia, seismometers in Mexico City picked up a spike in seismic activity. Mexico’s Institute of Geological and Atmospheric Research claims these tremors were caused by thousands of soccer fans jumping up and down in celebration, but some scientists are not so sure.

“It was probably a person, or people, jumping up and down next to the [seismology] station,” says Xyoli Pérez Campos, who heads Servicio Sismológico Nacional (SSN), Mexico’s national seismological service. Campos says the vibrations picked up by the seismometers do not resemble an