During the COVID-19 outbreak, most countries imposed lockdowns with varying levels of stringency to contain the spread of the novel coronavirus
COVID-induced lockdowns caused 50 percent drop in seismic noise, with the main quiet being observed from March to May 2020, according to research conducted by a team of 76 scientists.
"We have provided a global-scale analysis of high-frequency anthropogenic seismic noise. Global median hiFSAN dropped by as much as 50 percent during March to May 2020. The length and quiescence of this period represents the longest and most coherent global seismic noise reduction in recorded history, highlighting how human activities impact the solid Earth."
The research was led by the Royal Observatory of Belgium and other institutions, including Imperial College London and the University of Auckland in New Zealand.
The period of seismic quite is likely due to the combined effect of social distancing, industrial shutdowns and drops in travel and tourism across the globe.
During the COVID-19 outbreak, most countries imposed lockdowns with varying levels of stringency to contain the spread of the novel coronavirus.
The study also found a correlation between seismic noise and human mobility."While the reduction is strongest at surface seismometers in populated areas, this seismic quiescence extends for many kilometers radially and hundreds of meters in depth. This provides an opportunity to detect subtle signals from subsurface seismic sources that would have been concealed in noisier times and to benchmark sources of anthropogenic noise," the scientists said.