Electromagnetic manifestations of Tonga eruption in Schumann resonance band

We present results of concurrent observations of anomalous Schumann resonance (SR) signals during the major phase of eruption of Tonga volcano on 15 January 2022. The experimental data were recorded at French, Italian, Russian, and Japanese observatories that monitor natural electromagnetic signals in the ELF and ULF bands. The major phase of eruption ended by a huge blast, and all ELF/ULF observatories concurrently detected anomalous SR signals for the first time in the ELF observations, while the ULF records showed nothing unusual. The paper presents anomalous dynamic SR spectra detected at four widely separated observatories during the Tonga eruption on January 15, 2022. We show that a fourfold increase in the SR intensity was caused by a compact ELF source localized in the vicinity of Tonga volcano during the major and concluding phase of eruption. Thus, the volcanic SR anomaly emerged from the enormous amount of lightning strokes in the erupted cloud.