Multi-disciplinary constraints on the onset and early evolution of the May 2026 Titan Ridge submarine eruption

The onset and early evolution of submarine volcanic eruptions are rarely observed directly, limiting our understanding of the processes that govern shallow marine volcanism. Here, we reconstruct the first 3 weeks of the May 2026 eruption of Titan Ridge Volcano, Bismarck Sea, Papua New Guinea from a large multi-disciplinary dataset: regional seismic records, a hydroacoustic array at 3159 km range, and multi-sensor satellite imagery. Coherent acoustic radiation began at 08:04 UTC on May 8, 17 min before the first regional seismic detection, 4 h before the largest earthquake, and 17 h before any surface expression was visible from orbit. The combination of hydroacoustic array data with high spatial resolution satellite data enables both precise timing of acoustic onset and precise location of the eruption source. Multi-sensor satellite observations document two upwelling zones located ~ 2.5 km apart atop the volcanic eruption, and track their migration over time. The sea-surface features suggest that the discolored-water and pumice-raft products were sourced from multiple eruptive vents. These vents fed pumice rafts giving a dense-rock-equivalent volume of at least 0.011 to 0.014 km 3 and a time-averaged discharge of order 10 4 kg s −1 , from a pre-eruption vent depth of 400 to 700 m. Our study demonstrates the potential of combining seismic, hydroacoustic, and satellite-based observations for the detection and characterization of remote shallow submarine eruptions in tectonically complex and sparsely monitored oceanic environments.