The 2024-2026 Kīlauea eruption sequence: eruption patterns, magma source migration and the evolution of the plumbing system

Kīlauea, Hawaii, one of the world's most active volcanoes, has experienced 40 episodic eruptions (at the time of writing) with remarkable lava fountain heights in Halemaʻumaʻu Crater since December 2024. Following a dike intrusion and successive opening of a conduit to the surface within the Halemaʻumaʻu crater on December 23rd 2024, the eruption episodes entered a stable pattern from January 2025 onwards, consisting of ~hours-long lava fountain events separated by days-to-weeks long repose periods. Lava fountaining events have reached heights of 450 m and all lava flows to date have been confined to Halemaʻumaʻu crater.We study this outstanding eruption sequence with a combination of seismic and geodetic data analyses to understand how melt moves through Kīlauea’s plumbing system and how the system has evolved over time. We estimate the location of seismic tremor, which is the most dominant seismic signal of this eruption sequence, to study the eruption dynamics and inter-eruptive recharge of magma reservoirs. We also examine relative changes in frequency (df/f) and seismic velocity (dv/v), as well as tilt, GNSS and InSAR data. Taken together, these data allow us to study the geophysical response to the eruption dynamics in close detail.We infer that the current eruptions are controlled by a complex subsurface magma plumbing system with migrating melt sources. We derive three distinct phases of activity which show the subsequent deflation of a shallow and then deeper magma reservoir, as well as melt recharge from depth and the dynamics of the shallow reservoir controlling the lava fountaining. Our study sheds light on the dynamics between different magma reservoirs and links to surface processes. It further showcases how tremor locations could be used, in combination with seismic velocity changes, to track melt movement in near-real time in the future.