COVID-19 lockdowns sent seismic noise plummeting

An international team of researchers used data from seismic stations in 117 countries to determine that restrictions aimed at preventing the spread of COVID-19 led to an unprecedented drop in noise.

The study published in the journal Science shows seismic noise, or vibrations generated by human activity, dropped by as much as 50 per cent in March and April, particularly in urban areas.

Mika McKinnon, one of the study's authors, says they've dubbed this quiet period the "anthropause," as traffic, planes, cruise ships, conventions, concerts and sports games slowed or stopped.

And while it was most pronounced in cities, McKinnon says the sound of silence could also be seen in data from an abandoned mine shaft in Germany that's one of the quietest places on Earth.

The adjunct professor in the department of earth, ocean and atmospheric sciences at the University of British Columbia says a seismic station in Vancouver showed noise levels plummeted when the province closed schools, followed by bars, restaurants and other establishments.

As the pandemic wears on, McKinnon says data from the quiet period will help scientists detect more earthquakes and differentiate better between human-caused and natural seismic noises.

"We're getting a much better understanding of what these human-generated wave shapes are, which is going to make it easier in the future to be able to filter them back out again."

The latest data won't help predict if and when earthquakes will hit, but it does offer scientists deeper insight into the planet's seismology and volcanic activity, McKinnnon says.