Scientists from the Royal Observatory of Belgium, Brussels have observed a decline in vibrations within the Earth’s crust. Something that is observed only during holidays, scientists say that reduced human activity, due to the government imposed lockdown is causing the same effect.
Normally, the vibrations caused due to the hustle and bustle from cities can even bore through to the crust leading to anthropogenic noise— disturbances in seismic waves due to human activities. And scientists have observed a reduction in these disturbances within Earth’s crust.
According to an article in Nature, the seismometer at the Royal Observatory of Belgium observed about a one-third reduction in anthropogenic noise. Seismologist Thomas Lecocq from the Royal Observatory of Belgium described that a reduction is only experienced around Christmas.
Such reductions have been observed all over the world. Gizmodo reports that other seismologists from the United Kingdom, France and New Zealand have observed a similar reduction in the areas where lockdown has reduced human activity. But this will be limited to areas where there was human activity in the first place.
Most seismological studies are conducted in remote areas where the effect of anthropogenic noise is very low. So, seismometers at these locations will see a smaller decrease in noise compared to the ones located near cities like Brussels.
The reduction in noise is allowing them to detect earthquakes of smaller magnitude and better monitor seismic activity. This will allow seismologists to get better data based on the seismic activity due to ocean waves and even volcanoes as the sensitivity of the instrument are essentially boosted.
So, yes, the reduced human activity has led to reduced disturbances, but that doesn’t mean the Earth has stopped shaking. Prof. Supriyo Mitra from the Indian Institute of Science Education and Research (IISER) Kolkata explains to Economic Times that it would be wrong to say Earth’s crust is “moving or shaking slowly”.