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The April 27, 2016 eruption sequence at White Island was comprised of 6 discrete eruptive events that occurred over a 35-min period. Seismicity included three episodes of VLP activity: the first occurring ~ 2 h and a second occurring 10 min prior to the first eruption. A third larger VLP event occurred just prior to the fourth eruption. A VLP source depth of 800-1000 m below the vent is obtained from an analysis of the waveform semblance, and a volumetric source is obtained from waveform inversion of the largest VLP event. Lag times between VLP occurrence and eruption onsets provide an opportunity to examine gas migration and stress transfer models as potential triggers to the eruptive activity. Plausible lag times for a deep gas pulse to the surface are obtained by application of a TOUGH2 computational model which suggests propagation times of 0.25-1.9 m/s and are informed by previously measured White Island rock porosities and permeabilities. Results suggest that pre-eruption VLP may be plausibly linked to advection of gas from the VLP source at a magmatic carapace located ~ 800-1000 m depth. Alternatively, the large VLP that occurred just prior to the fourth eruption may be linked to a quasi-dynamic or quasi-static stress perturbation. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

At approximately 09:36 UTC on 27 April 2016, a phreatic eruption occurred on Whakaari Island (White Island) producing an eruption sequence that contained multiple eruptive pulses determined to have occurred over the first 30 min, with a continuing tremor signal lasting ~ 2 h after the pulsing sequence. To investigate the eruption dynamics, we used a combination of cross-correlation and coherence methods with acoustic data. To estimate locations for the eruptive pulses, seismic data were collected and eruption vent locations were inferred through the use of an amplitude source location method. We also investigated volcanic acoustic-seismic ratios for comparing inferred initiation depths of each pulse. Initial results show vent locations for the eruptive pulses were found to have possibly come from two separate locations only ~ 50 m apart. These results compare favorably with acoustic lag time analysis. After error analysis, eruption sources are shown to conceivably come from a single vent, and differences in vent locations may not be constrained. Both vent location scenarios show that the eruption pulses gradually increase in strength with time, and that pulses 1, 3, 4, and 5 possibly came from a deeper source than pulses 2 and 6. We show herein that the characteristics and locations of volcanic eruptions can be better understood through joint analysis combining data from several data sources.

Long‐period (LP) volcano seismic events often precede volcanic eruptions and are viewed with considerable interest in hazard assessment. They are usually thought to be associated with resonating fluid‐filled conduits although alternative models involving material failure have recently been proposed. Through recent field experiments, we uncovered a step‐like displacement component associated with some LP events, outside the spectral range of the typically narrow‐band analysis for this kind of event. Bespoke laboratory experiments with step tables show that steps of the order of a few micrometers can be extracted from seismograms, where long‐period noise is estimated and removed with moving median filters. Using these constraints, we observe step‐like ground deformation in LP recordings near the summits of Turrialba and Etna Volcanoes. This represents a previously unobserved static component in the source time history of LP events, with implications for the underlying source process.