New research published in the journal Science has shown that lockdown measures to combat the spread of COVID-19 have led to a 50% reduction in seismic noise observed around the world from during 2020.

NCEO scientist Dr Simon Proud is a co-author on the paper, which was led by Dr. Thomas Lecocq and involved a large collaboration of 76 authors from 66 institutions in 27 countries. The study’s lead authors are based in Belgium, the United Kingdom, New Zealand and Mexico.

Dr Lecocq and colleagues compiled seismic observations from over 300 seismometers around the world and found a near-global reduction in high-frequency seismic ambient noise, which began in China in late January 2020 and was followed by the same phenomenon in Europe and the rest of the world in March to April.

Seismometers are sensitive scientific instruments to record vibrations travelling through the ground – known as seismic waves. Traditionally, seismology focuses on measuring seismic waves arising after earthquakes. Seismic records from natural sources however are contaminated by high-frequency vibrations (“buzz”) from humans at the surface – walking around, driving a car, and getting the train all create unique seismic signatures in the subsurface. Heavy industry and construction work also generate seismic waves that are recorded on seismometers.

The seismic noise reduction over recent months makes clear the total effect of physical/social distancing measures, reduced economic and industrial activity, and drops in tourism and travel. The 2020 seismic noise quiet period, coined the “anthropause” is the longest and most prominent global anthropogenic seismic noise reduction on record. This research shows noise levels drop by up to 50% in some places, and the lockdown effect is even visible in stations hundreds of metres below the ground and in remote areas.

Dr Proud analysed aircraft flight data for Barbados international airport, showing a substantial drop in the number of flights that corresponds to a reduction in local seismic noise – highlighting the effect of Barbados’s COVID curfew and lock-down on tourism and the local economy.

Simon Proud (co-author ad NCEO Scientist) comments:

“The drop in seismic noise is an eye-opening illustration of global efforts to combat the Coronavirus, and this seismic data gives a unique insight into broad changes in human behaviour before, during and after the lock-down. We believe that this data will enable us to track the effectiveness of lock-down measures and the subsequent global recover, and represents an alternative to other methods such as mobile phone tracking that are associated with various privacy concerns.

Now, we plan to follow up on this work by linking with other NCEO scientists to look at how this data can be linked to environmental changes over the past few months and, for me, to examine the detailed environmental and seismic effects of the shutdown in the aviation industry.”

To view the article in the journal Science click here.

Flight data provided by Dr S Proud and the Opensky Network. Seismic data provided by Dr Paula Koelemeijer using code developed by Thomas Lecocq