A round the world, seismologists are observing something very very significant – a lot less ambient seismic noise, which means the vibrations generated by cars, railway trains, buses and people going about their daily lives has drastically reduced. And in the absence of that noise, Earth’s upper crust is moving just a little less. Thomas Lecocq, a seismologist with the Royal Observatory of Belgium in Brussels has claimed that the observatory has in the past few weeks observed a significant drop in seismic noise because of more than half the countries going into the lockdown mode due to the COVID-19 outbreak. Lecocq, in an article published in the journal Nature, has reportedly also said that the COVID-19 lockdowns globally have not only made air more breathable or rivers cleaner, but have also resulted in the way our Earth moves. According to the article, researchers have reported that there is a drop in seismic noise (the hum of vibrations in the planets crust) because transport networks, real estate and other human activities have come to a near-total halt. According to the article, efforts to curb the spread of coronavirus mean that planet Earth itself is moving a little less, which could “allow detectors to spot smaller earthquakes and boost efforts to monitor volcanic activity and other seismic events.” Vibrations caused by the movement of vehicles including railway trains, and running of industrial machinery produce a background noise, which reduces the ability of seismologists to detect other signals occurring at the same frequency. A fall in human-induced noise – which is literally drastic, thanks to the gloal pandemic – could boost the sensitivity of detectors to natural waves at similar frequencies, scientists have said. On the flip side, Assam felt a brief but significant tremor – 4.4 on the Richter scale – at around 11:20 pm on Sunday, with the epicentre identified near Dhing in Nagaon district, bordering Morigaon district. What could be the reason when there has been a worldwide fall in seismic noise? Any guess?
Earth shaking less?