Since seismic waves produce sound waves, the information carried by them is transferred from the ground to the atmosphere. In this way, it is feasible to obtain valuable scientific information by studying sound waves from the air in a similar way to how conventional seismologists would study seismic waves from the ground. Following this strategy, a globe properly equipped with highly sensitive scientific instruments can detect an earthquake.
Between July 4-6, 2019, a sequence of powerful earthquakes rumbled near Ridgecrest, California, triggering more than 10,000 aftershocks in a six-week period. Seeing an opportunity to test their scientific ideas, researchers from the California Institute of Technology (Caltech) and NASA’s Jet Propulsion Laboratory (JPL), all these entities in the United States, flew over the region with instruments attached to balloons. high altitude, hoping to make the first detection from a balloon of a naturally occurring earthquake. His goal was to test a new technology designed for future applications on Venus, where globes equipped with scientific instruments could detect earthquakes from high up in the atmosphere, without the need to send devices to the much more hostile surface.
And they succeeded. On July 22, the highly sensitive barometers (instruments that measure changes in air pressure) on one of the balloons detected the low-frequency sound waves caused by an aftershock on the ground.
In a new study, the team that worked with these globes describe how a similar technique could help reveal Venus’s innermost mysteries, without going down to its surface where temperatures are hot enough to melt lead and pressures. atmospheres are high enough to crush a submarine.
When heated by the Sun, balloons of this kind rise up in the atmosphere; at dusk they descend. (Image: NASA JPL / Caltech)
Venus, roughly the size of Earth, is believed to have been in its most hospitable day before transforming into a strikingly different place in our world. Scientists are not sure why this transformation occurred.
One way to find out how a rocky planet evolved is to study what’s inside it, and one of the best ways to do that is to measure the seismic waves that bounce under its surface. On Earth, different materials and structures refract these underground waves in different ways, characteristic of each type of material or structure. By studying the strength and velocity of waves produced by an earthquake or explosion, seismologists can determine what rock layers look like below the surface and even locate deposits of liquid, such as oil or water. These measurements can also be used to detect volcanic and tectonic activity.
JPL and Caltech have been developing this balloon-based seismology technique since 2016.
If the same detection capacity that was demonstrated with the 2019 Californian earthquakes is achieved on Venus, we will be facing a way to study the enigmatic interior of the planet without having to land any vehicle on its infernal surface. In the new study, Jennifer M. Jackson of the Caltech Seismological Laboratory and her colleagues lay out the technical details of the concept. The study is titled “The First Detection of an Earthquake From a Balloon Using Its Acoustic Signature.” And it has been published in the academic journal Geophysical Research Letters. (Source: NCYT from Amazings)