Seismic Constraints of the 23 November 2025 Hayli Gubbi Eruption Sequence in Afar, Ethiopia

On 23 November 2025, the Hayli Gubbi volcano in Afar (Ethiopia) erupted in a massive explosion. We present the first seismic characterization using data from 13 regional seismological stations. Seismograms reveal signals consisting of a minute‐long precursor, a main eruptive phase, and secondary events hours later. The main phase comprised a fast succession of two major seismic events separated by minutes and recorded 20 min after initial gas release detected by satellites. Sources are localized near Hayli Gubbi by jointly inverting epicentral coordinates and wave velocity from surface‐wave arrivals. Numerical modeling using an isotropic source mechanism reproduces the observed waveform accurately. Pulse‐like signals preceding the main events may reflect ongoing volcanic outbursts or subsurface processes leading up to the Hayli Gubbi explosion or potential collapse at Erta Ale, clearly observed in satellite imagery. This study highlights the value of using a regional seismic network for monitoring under‐instrumented volcanoes in Afar.