The COVID-19 lockdowns of 2020 reduced the ambient noise on Earth by up to 50%, according to research from the Swiss Seismological Service at ETH Zurich. The scientists analyzed measurements from 268 seismic sensing stations around the globe and found lower noise levels at 185 of them locations. The reduced human noise enabled researchers to better study tiny earthquakes that might have been drowned out by the hum of human activity. From Reuters:
Urban ambient noise fell by up to 50% at some measuring stations during the tightest lockdown weeks, as buses and train services were reduced, aircraft grounded and factories shuttered.
"The weeks during lockdown were the quietest period we have on record," said seismologist John Clinton, referring to data archives covering the last 20 years.
"With human noise always increasing, it is highly likely that it was the quietest period for a very long time."