DID THE LOCKDOWN OF SLOVENIA DUE TO COVID-19 CAUSE A REDUCTION IN SEISMIC NOISE

Abstract

Following the outbreak of Covid-19 in the first half of 2020, special measures were introduced in most countries, which drastically limited various human activities. These measures were given the uniform term “lockdown”. Shortly after they began, reports came from some seismological centres that in larger urban areas seismometers were detecting significantly less seismic noise at high frequencies in a seismological sense. There was interest in whether this phenomenon had also been observed in Slovenia. In fact it was not directly detected at the Slovenia National Seismic Network (SNSN), but it was detected at the seismic station located in the area of Ljubljana-Bežigrad. Indirectly, the phenomenon was also detected at two seismic stations of the SNSN, but with high-frequency seismic noise actually increasing at one of them. On 12 April 2020, we also noticed an interesting phenomenon – the reduction of high-frequency seismic noise during the day at most seismic stations, which was also related to the lockdown.