Exclusive Seismoacoustic Detection and Characterization of an Unseen and Unheard Fireball Over the North Atlantic

• Main Authors: Hicks, Stephen P, Matos, Sandro B, Pimentel, Adriano, Belli, Giacomo, Gheri, Duccio, Tsekhmistrenko, Maria, Hosseini, Kasra, Geissler, Wolfram H, Silva, Rita, Wallenstein, Nicolau, Ferreira, Ana MG
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2023
• Subjects: North Atlantic
• Online Access: https://discovery.ucl.ac.uk/id/eprint/10181805/1/Hicks_Exclusive%20Seismoacoustic%20Detection%20and%20Characterization%20of%20an%20Unseen%20and%20Unheard%20Fireball%20Over%20the%20North%20Atlantic_VoR.pdf; https://discovery.ucl.ac.uk/id/eprint/10181805/

Small meteoroids that enter Earth's atmosphere often go unnoticed because their detection and characterization rely on human observations, introducing observational biases in space and time. Acoustic shockwaves from meteoroid ablation convert to infrasound and seismic energy, enabling fireball detection using seismoacoustic methods. We analyzed an unreported fireball in 2022 near the Azores, recorded by 26 seismometers and two infrasound arrays. Through polarization analyses, array methods, and 3‐D ray‐tracing, we determined that the terminal blast occurred at 40 km altitude, ∼60 km NE of São Miguel Island. This location matches an unidentified flash captured by a lightning detector aboard the GOES‐16 satellite. The estimated kinetic energy is ∼10−3 kT TNT equivalent, suggesting a 10−1 m object diameter, thousands of which enter the atmosphere annually. Our results demonstrate how geophysical methods, in tandem with satellite data, can significantly improve the observational completeness of meteoroids, advancing our understanding of their sources and entry processes.