On 14 December 2021, a 7.3-magnitude earthquake struck Indonesia; its epicentre was located just under the seabed near the island of Flores.
Within minutes, seismometers around the world were jolted by the earthquake waves as they rippled through and around the Earth.
And, for the first time, a network of balloons, 12 miles (20km) above Earth’s surface and as far as 190 miles away from the source, felt the impact of the earthquake via the pressure waves travelling through the atmosphere.
In the case of the Flores earthquake, the balloon data did not especially add to our knowledge but scientists are excited by the potential of this technique for measuring earthquakes in hard-to-reach places such as the planet Venus, whose hot surface and cloudy corrosive atmosphere limits our ability to observe quakes there.
Three missions to Venus have been accepted for the early 2030s and several teams are working on balloon-based seismic monitoring. “The story for our interest in Venus is that we know nothing of its interior,” said Raphaël Garcia, from the University of Toulouse, France.
“We don’t know how it’s made inside, and on Earth, seismology is one of the best tools to figure that out.”
The findings are published in Geophysical Research Letters.