But the response to the pandemic has unwittingly produced some other large-scale, though less conspicuous, effects. In a bittersweet twist, the surreal slowdown of life as we know it has presented researchers with a rare opportunity to study the modern world under some truly bizarre conditions, and they’re scrambling to collect as much data as they can. Here are four ways the pandemic is being felt across land, air, and sea.

There’s less rumbling on the surface

Seismologists around the world have noticed the same effect Koelemeijer detected in London, and at more traditional stations than a fireplace.

The trend started with Thomas Lecocq, a seismologist at the Royal Observatory of Belgium, in Brussels. Seismic stations are usually found well outside metropolitan areas, away from vibrations that could obscure subtle tremors within Earth’s interior, but the Brussels station was established more than a century ago, before a city grew around it. Today, it provides a fascinating glimpse of the ebb and flow of a bustling city; Lecocq has found that when it snows, anthropogenic seismic activity decreases, and on the day of a road race, it spikes. Lecocq checked seismic data the day before Belgium began a nationwide lockdown, and then the following morning. The drop in activity, he said, was “immediate.” Right now, daytime in Brussels resembles Christmas Day.

Lecocq shared his approach online, and seismologists in the United States, France, New Zealand, and elsewhere are now seeing the effects of their country’s own social-distancing measures on seismic activity. For seismologists who study seismic signals from Earth’s interior—rather than other sources, including people, animals, even storms—quarantines seem to have made it easier to listen. “Normally we wouldn’t pick up a 5.5 [magnitude earthquake] from the other side of the world, because it would be too noisy, but with less noise, our instrument is now able to pick up 5.5’s with much nicer signals during the day,” Koelemeijer said.

There’s Less Air Pollution

As cities and, in some cases, entire nations weather the pandemic under lockdown, Earth-observing satellites have detected a significant decrease in the concentration of a common air pollutant, nitrogen dioxide, which enters the atmosphere through emissions from cars, trucks, buses, and power plants. The drop, observed in China and Europe, coincided with stringent social-distancing measures on the ground. Air pollution can seriously damage human health, and the World Health Organization estimates that conditions stemming from exposure to ambient pollution—including stroke, heart disease, and respiratory illnesses—kill about 4.2 million people a year.

Read: 5 big trends that increased Earth’s carbon pollution

The cleaner air could lead to a brief respite in parts of the world with severe air pollution even as they battle the coronavirus. According to an analysis by Marshall Burke, a professor in Stanford’s Earth-system science department, a pandemic-related reduction in particulate matter in the atmosphere—the deadliest form of air pollution—likely saved the lives of 4,000 young children and 73,000 elderly adults in China over two months this year.