Scientists at Penn State University recorded the sounds associated with COVID-19-related lockdowns and subsequent re-openings using underground telecommunication fiber optic sensors.

To better understand the impact of COVID-19 lockdowns on the human activities of those living in and around the Penn State University Park campus and State College, Pennsylvania, scientists began analyzing sound signals captured by underground fiber optic sensors between March 2020, which was the start of COVID-19 associated lockdowns, and June 2020, when the state moved to different phases of re-opening.

To assess the impact of the COVID-19 lockdowns and subsequent re-openings on human activity, the team employed the telecommunication fiber optic cables already underneath the campus. Using technology dubbed a distributed acoustic sensing (DAS) array, scientists sent a laser to the fibers contained within the fiber optic cables to detect changes caused by pressure. These measurements were reportedly taken every 6.5 ft, creating a network of about 2,000 sensors.

Source: Patrick Mansell, Penn State University

Examining the small vibration changes detected at the surface, the team determined that construction activity and vehicle traffic recovered faster than pedestrian activity.

"Footsteps disappeared and really did not recover after business re-opening in late May," said Tieyuan Zhu, assistant professor of geosciences at Penn State University. "But if you look at car traffic, it shows a different pattern. It decreased and recovered. This may give us a hint that people were conservative, working remotely and driving when they had to go outside for things like groceries."

According to the team of scientists, the findings serve as a tool for determining how well lockdown efforts work in the event of future pandemics as well as a better understanding of how a pandemic impacts human activities.

The team reported their findings in the journal The Seismic Record.