Seismometers may be built to detect earthquakes, but their mechanical ears hear so much more: hurricanes thundering hundreds of miles away and meteoroids exploding in the skies on the other side of the planet. Even the everyday hum of humanity — people moving about on cars, trains and planes — has a seismically detectable heartbeat.

But coronavirus has upended our lives. Hoping to curtail the pandemic’s spread, nations have closed their borders, cities have been shut down and billions of people have been instructed to stay home. Today, in cities large and small, the thumping pulse of civilization is now barely detectable on many seismograms.

“It did make the scale of the shutdowns a bit more real to me,” said Celeste Labedz, a graduate student in geophysics at the California Institute of Technology.