Balloon seismology enables subsurface inversion without ground stations

Earth’s interior structure is derived primarily from data recorded by ground-based seismometers. Such instruments would provide essential insight into the composition and evolution of Venus, but harsh surface conditions hinder their deployment. Balloon-borne seismology offers an alternative by capturing upper-atmospheric infrasonic signatures of seismic waves. We show that subsurface seismic velocities and earthquake source location can be jointly inverted from balloon observations. We demonstrate this method using infrasound signals recorded by four stratospheric balloons following a major earthquake in the Flores Sea, Indonesia. A Bayesian inversion using Markov chain Monte Carlo sampling is implemented to account for trade-offs in the joint location and subsurface velocity estimation. The inverted seismic parameters are consistent with results obtained using ground-based seismometers. This demonstration of the ability to estimate source and velocity parameters without ground deployments motivates further development of seismo-acoustic mission concepts to Venus, and provides new opportunities for seismic exploration in remote Earth regions. Balloon-borne infrasound data enables joint inversion of earthquake source location and velocity structure, matching results from ground-based seismometers and opening new paths for seismic exploration on Venus and remote Earth regions.