Ground vibrations attenuated in cities where the moon completely obscured the sun
Seismic data captured the tense calm of confinements linked to COVID-19 and the Thunderous excitement from Taylor Swift’s Eras tour. And now another human experience has been written into seismic signals: the shock and awe of witnessing a total solar eclipse.
When a solar eclipse swept across North America on April 8, 2024, there was a lull in seismic vibrations across the continentshows a new analysis – at least in places where the spectacle stopped human observers in their tracks.
Seismic activity decreased during the eclipse in cities that were in the path of totality, where the moon completely obscured the sun. But this pattern did not manifest itself in rural areas or cities outside the path of totality. This suggests that the seismic changes were due to human unrest that stopped during the eclipse, Benjamin Fernando reported April 17 at the annual meeting of the Seismological Society of America in Pasadena, California.
As Fernando watched the 2024 eclipse with friends in Cleveland, he was struck by how calm the world was during those few minutes of totality. As a seismologist, he immediately wondered whether this sensation of the world holding its breath would manifest itself in seismic signals.
Fernando examined data collected by around 250 seismometers. He focused on seismic rumbles with frequencies from about 1 to 50 hertz, because human-caused vibrations — from traffic, machinery and other sources — are expected to be strongest in that range.
Cities in the path of totality, from Dallas to Montreal, had quieter ground vibrations at all frequencies during the eclipse compared to the rest of April 2024. The largest drop was seen in Cleveland, where seismic vibrations at some frequencies were 8 to 9 decibels quieter during totality than the monthly average.
“I’m pleasantly surprised by how clearly these signals appear and I’m curious if we can do similar analyzes on other events,” says Fernando, of Los Alamos National Laboratory in New Mexico. In another recent study, he reported a seismic silence that fell on Seattle during the 2026 Super Bowl — perhaps because so many Seattleites were glued to their TVs, watching their hometown Seahawks compete in California.
Caltech seismologist Gabrielle Tepp measured the ground shaking caused by the tilting of a Swifties stadium. By studying artificial seismic signatures, she says, “we could potentially use seismic instruments to monitor human activity.” This could be useful for designing cities or planning large events, from parades to the World Cup and Olympics.
