A new study showed that the ground tremors resulting from traffic and industrial works fell by half globally during the global shutdown due to the "Covid-19" pandemic.

The social divergence, and the limited number of cars on the roads, while limiting tourism and travel, led to the "longest and most visible period of calm" of seismic noise in recorded history.

Seismic noise refers to vibrations in the ground, caused by traffic or heavy machinery and natural phenomena, such as earthquakes and bad weather.

Global (anthropogenic) seismic noise decreased by 50% during the period from March to May, as the provinces entered a closure to prevent the SARS-CoV-2 spread.

The largest decrease in seismic noise was recorded in the most densely populated regions around the world, such as Singapore and New York City.

However, a decrease in seismic noise was recorded in remote areas, such as the German Black Forest and Rondo in the African country of Namibia.

The closure gave geologists an opportunity to monitor natural events, which may have remained undiscovered - especially during the day when there is more human-made noise.

This relative calm allowed scientists to listen to signs of previously hidden earthquakes, and could help distinguish between human and natural seismic noise more clearly than ever before.

The study, which includes contributions from experts at Imperial College London, provides the first evidence that seismic signals that were previously hidden, were more evident in urban seismometers during closure.

This can help ecologists find ways to predict upcoming natural disasters.

"With increasing urbanization and a growing world population, more people will live in geologically dangerous areas. Therefore, it will become more important than ever before to distinguish between natural noise and the noise that it causes," said lead author Dr. Thomas Lockoc of the Royal Belgian Observatory. The human being, so that we can "listen" and better observe the ground movements under our feet. This study can help start this new field. "

The research team used devices called seismometers to measure seismic noise, which travels like waves and can also be caused by earthquakes, volcanoes and bombs, in addition to daily human activity such as travel and industry.

The researchers relied on professional seismographs and "citizen seismographs" - smaller devices that can be ordered online and assembled at home.

Dr. Lucoc and colleagues studied seismic data from a global network of 268 seismic stations, in 117 countries.

The team found that noise levels decreased during closure at 185 from 268 seismic stations, set globally.

In a permanent seismic station in Sri Lanka, there was a 50% decrease in seismic noise after closure, which is the strongest that the team has observed in the data available from that station since at least July 2013