COVID-19 made an impact on people all over the world, but curiously, it’s reduced our impact on the planet. The New York Times reports that self-quarantining has had an observable effect on seismic activity beneath city streets.

Thomas Lecocq, a seismologist at the Royal Observatory of Belgium in Brussels, measured the seismic noise beneath the city after Brussels established a lockdown in mid-March. He found that it had diminished quickly and significantly once Belgians and their cars were off the streets.

Other scientists around the world have followed his lead and detected similar declines. In Great Britain, one seismologist tracking activity from her suburban house observed a 20%–25% reduction in average weekly noise one week after the British commenced their lockdown.

In the center of London, another seismometer recorded a 30% drop. Similarly, noise levels in Los Angeles have declined more than 50% of normal, and the Paris Institute of Earth Physics has detected a 38% drop in average daytime seismic noise in the city. It seems that all our footsteps have more an impact than we realized.