The drop in activity on Malta's roads since people were asked to stay indoors because of COVID-19 has been such that it has even been detected by seismograph stations which were set up to detect earth tremors. 

The Malta Seismic Network, operated by the Department of Geosciences of the University of Malta has seven state-of-the-art digital seismographs in Malta, Gozo and Comino.

Their aim is to detect local and regional earthquakes, but the sensitive instruments also record ground vibrations originating from man-made sources such as traffic and industrial machinery, as well from natural sources such as wind and sea waves.

"The figures show the level of background seismic noise over the past few weeks recorded at the seismic station installed in the grounds of the University Msida campus. The daily variation in noise level between night and day can be observed and the sharp reductions in daytime noise is evident on Sundays and public holidays. However, these peaks have dropped even further, by about 20 - 25%, over the past few weeks, when the public was urged to stay indoors, as shown by the lines on the graph. This indicates a substantial decrease in traffic on the nearby Regional Road and Birkirkara Bypass," the seismic network said.

Similar observations have been noted across Europe.

Thomas Lecocq, a seismologist at the Royal Observatory in Belgium, discovered that ambient seismic noise has fallen drastically in Brussels since mid-February, around the time the country closed schools and businesses. Whilst the decrease in social activity is unwelcome by society, it may give seismologists the opportunity to detect smaller earthquakes whose weak signal is usually lost in the cultural noise, the centre said.