The pandemic-led shutdowns have resulted in what appears to be the longest and highly reduced global seismic noise in recorded history! The shock waves and noise of civilization travels through the rocky ground and ricochets around the planet, as geologists have learnt from decades of listening and looking out for earthquakes using sensitive seismometers. However, Covid19 and lockdowns led to an unprecedented period of silence which resulted in sharpening the ability of scientists differentiating between human-caused noise and signals of upcoming natural disasters like an earthquake, and there has been a 50% global reduction in human-caused noise/vibrations, and this relative quietness has allowed scientists to listen to hidden earthquake signals that were previously concealed.
This 50% reduction has been noted by a team of 70+ scientists from more than 24 countries in a study led by Royal Observatory of Belgium, the University of Auckland in New Zealand and the Imperial College London, and others. Dr Thomas Lecocq, lead author of the study from the Royal Observatory of Belgium wrote, “With increasing urbanization and growing global populations, more people will be living in geologically hazardous areas. It will, therefore, become more important than ever to differentiate between natural and human-caused noise so that we can listen in and better monitor the ground movements beneath our feet. This study could help to kickstart this new field of study.” The main quieting, that took place from March to May, was compared with noise levels of previous months. It began in China in late January and spread to Europe and across the world by March and April. These researchers further added that physical isolations, social distancing, drops in travel and tourism, and industrial shutdowns have majorly contributed to the quieting.
Participants of this team included the seismological laboratory in Albuquerque of the U.S. Geological Survey, as well as Stanford University, Princeton University, the University of Alaska, the University of California, and the University of Maine. 337 seismometers run by citizen scientists along with 268 stations run by corporate, university and government geologists. The authors further explain how seismometers that measure seismic vibrations within the planet are interconnected to tracking human activities, “Like earthquakes and other geophysical processes and events, humans are a major source of seismic signals detected by seismometers worldwide. Everyday human activity — from our involvement in industrial processes and construction projects to our raucous outbursts at football stadiums — generates vibrations in the earth that are recorded as a near-continuous stream of high-frequency seismic waves. In general, this seismic noise closely tracks with human behaviour; it’s typically stronger during the day than at night and weaker on weekends and holidays than it is on typical weekdays.” It is beautiful how the virus quarantining humans within their concrete boxes has given our planet a much needed quiet time, a break from the constant hustling of humans; indeed every cloud has a silver lining.