Detection of Artificially Generated Seismic Signals Using Balloon-Borne Infrasound Sensors

We conducted an experiment in Pahrump, Nevada, in June 2017, where artificial seismic signals were created using a seismic hammer, and the possibility of detecting them from their acoustic signature was examined. In this work, we analyze the pressure signals recorded by highly sensitive barometers deployed on the ground and on tethers suspended from balloons. Our signal processing results show that wind noise experienced by a barometer on a free-flying balloon is lower compared to one on a moored balloon. This has never been experimentally demonstrated in the lower troposphere. While seismoacoustic signals were not recorded on the hot air balloon platform owing to operational challenges, we demonstrate the detection of seismoacoustic signals on our moored balloon platform. Our results have important implications for performing seismology in harsh surface environments such as Venus through atmospheric remote sensing. Plain Language Summary Seismology has traditionally been performed by placing sensors on the ground. However, on Venus, high temperature and pressure on the surface drastically shorten the lifetime of sensors placed on the ground. This is one of the major reasons why we know so little about the interior of Venus. Earthquakes are known to generate pressure waves in the atmosphere at various frequencies. The low-frequency components are found to travel long distances with relatively little damping. Here we demonstrate that these waves can be detected by pressure sensors floating on balloons. By demonstrating that we can detect artificial earthquakes from their atmospheric signature using a pressure sensor suspended on a balloon, we motivate a new way to perform seismology on Venus-by detecting seismic waves while floating at a high altitude, where the temperature and pressure are more benign. The success of this technology offers a compelling alternative to landing on the surface and surviving for long periods of time to study the internal structure of Venus.