The 2018 rift eruption and summit collapse of Kīlauea Volcano

Abstract

In 2018, Kīlauea Volcano experienced its largest lower East Rift Zone (LERZ) eruption and caldera collapse in at least 200 years. After collapse of the Pu‘u ‘Ō‘ō vent on 30 April, magma propagated downrift. Eruptive fissures opened in the LERZ on 3 May, eventually extending ~6.8 kilometers. A 4 May earthquake [moment magnitude (Mw) 6.9] produced ~5 meters of fault slip. Lava erupted at rates exceeding 100 cubic meters per second, eventually covering 35.5 square kilometers. The summit magma system partially drained, producing minor explosions and near-daily collapses releasing energy equivalent toMw4.7 to 5.4 earthquakes. Activity declined rapidly on 4 August. Summit collapse and lava flow volume estimates are roughly equivalent—about 0.8 cubic kilometers. Careful historical observation and monitoring of Kīlauea enabled successful forecasting of hazardous events.

Decrease in Seismic Velocity Observed Prior to the 2018 Eruption of Kīlauea Volcano With Ambient Seismic Noise Interferometry

“…We suggest that the South Caldera reservoir is pressurizing at this time, while a blockage prevents further pressurization of the Halema'uma'u reservoir. This in turn would require a volume change of 8 × 10 6 m 3 in the South Caldera reservoir, which is roughly 1% of the estimated total erupted volume of the 2018 LERZ eruption (Neal et al, 2019). The pre-eruptive decrease in dv/v we observe is 0.4 %.…”

“…Remarkably there are little other geophysical indication of instability at the summit during this time period (see chronology of events from USGS in the supporting information S2 and Neal et al, 2019). Remarkably there are little other geophysical indication of instability at the summit during this time period (see chronology of events from USGS in the supporting information S2 and Neal et al, 2019).…”

“…Although this constraint is speculative, it provides the only conceivable mechanism for the decrease in velocity before the eruption for an elastic model Therefore, we can model this as a deeper point source at 4 km depth (Anderson et al, 2015). Such a rapid volume change at the South Caldera reservoir in a 10-day period of time is unlikely, as it would require the magma supply to the South Caldera reservoir to be more than three times higher than the long-term rate (Neal et al, 2019), even when assuming no magma loss to the Halema'uma'u reservoir or the East Rift Zone. Assuming the velocity strain sensitivity found during intereruptive periods, we would need the strain change produced by the South Caldera reservoir to be more than +1.4 microstrain at a radial distance of 3 km from the Halema'uma'u reservoir.…”

Large‐Scale Drainage of a Complex Magmatic System: Observations From the 2018 Eruption of Ambrym Volcano, Vanuatu

“…The populations of many volcanic islands are concentrated along the coast away from the summit and main crater areas which are considered to have the highest hazard (Calder et al, ). However, recent major eruptions at Kīlauea and Bárdabunga (Neal et al, ; Sigmundsson et al, ) demonstrate that magma can be transported tens of kilometers from the main summit region. Mafic caldera systems are often associated with flank eruptions which are fed by magma draining out from a reservoir beneath the caldera floor (Neal et al, ; Sigmundsson et al, , e.g.).…”

Groundwater Inflow Toward a Preheated Volcanic Conduit: Application to the 2018 Eruption at Kīlauea Volcano, Hawai'i

“…In May–June 2018, during the evolving eruption of Kīlauea Volcano, Hawai'i (Neal et al, ), scientists relied heavily on analogy with the 1924 eruption, including a long‐standing conceptual model of explosive summit eruptions triggered when lava lake levels drop below the water table (Figure ).…”