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

On 23 November 2025, the Hayli Gubbi volcano in the Danakil Depression (Afar, northern Ethiopia) erupted in a massive explosion. We present the first seismic characterization of this event using data from ten regional seismological stations. Seismic records reveal a complex eruption sequence consisting of a minute-long precursor, a main explosive phase, and secondary events hours later. Two distinct surface-wave trains indicate that the main phase comprised two major explosions separated by minutes rather than a single event. The explosion sources were localized by jointly inverting epicentral coordinates and wave velocity from surface-wave arrivals. Waveform modeling supports an explosive sequence, as observed signals are reproduced only when two sequential sources are assumed. Pulse-like precursor signals minutes before the main explosions indicate pressurization, conduit processes, or magmatic fracturing prior to failure. This exceptional event provides new insights into the eruption and highlights the need for improved local monitoring in the region.