COVID-19 has made the planet less noisy, helping scientist
Unprecedented levels of public restrictions (like the lockdown in India) around the world amid the novel coronavirus disease pandemic (COVID-19) has surreally slowed life down.
Researchers from across the globe have found a rare opportunity to study the modern world and they are scrambling to collect as much data as they can. The impacts of the pandemic are being felt across land, air, and sea.
The Earth's crust moves less during a global Lockdown. According to geoscientists, seismic noise detectors in London, Paris and Brussels have recorded huge drops in vibrations.
Noises produced together from public transport, private cars, factories, agriculture, construction works and other day-to-day human activities mask the sound of seismic activity beneath the soil. This reduces seismologists’ ability to detect other signals occurring at the same frequency. Hence, the current less seismic noises phase is a boon for geoscientists around the world.
A seismologist from Royal Observatory of Belgium on Twitter reported a 33 per cent drop in noise levels on March 27, 2020. The current drop in noise level has raised the sensitivity of the observatory’s equipment, enhancing its ability to detect waves in the same high frequency range as the noise. Now, the surface seismometers are equally sensitive to small earthquakes and quarry blasts as its counterpart detector buried in a 100-metre borehole.
This can also boost efforts to monitor volcanic activity and other seismic events . Seismometers detect seismic waves (vibrations) in the Earth's crust. But they also pick up human-induced noises which show as high-frequency noise. If the lock down continues longer, city-based detectors may become able to detect the earthquake aftershock better.
However, stations purposefully located in remote areas or deep boreholes to avoid human noise may not be affected by this change. Reduced noise level could also benefit those seismologists who use naturally occurring background vibrations such as crashing ocean waves to probe Earth’s crust.
Because volcanic activity and changing water tables affect how fast these natural waves travel, scientists can study these events by monitoring how long it takes a wave to reach a given detector. A fall in human-induced noise could boost the sensitivity of detectors to natural waves at similar frequencies.
This is not only the land which has become quieter, there are other positive changes in the environment around the world. One of them is the clean air.