ABSTRACT
Lava flows present a recurring threat to communities on active volcanoes, and volumetric eruption rate is one of the primary factors controlling flow behavior and hazard. The time scales and driving forces of eruption rate variability, however, remain poorly understood. In 2018, a highly destructive eruption occurred on the lower flank of Kilauea Volcano, Hawai'i, where the primary vent exhibited substantial cyclic eruption rates on both short (minutes) and long (tens of hours) time scales. We used multiparameter data to show that the short cycles were driven by shallow outgassing, whereas longer cycles were pressure-driven surges in magma supply triggered by summit caldera collapse events 40 kilometers upslope. The results provide a clear link between eruption rate fluctuations and their driving processes in the magmatic system.
ABSTRACT
In 2018, Kilauea Volcano experienced its largest lower East Rift Zone (LERZ) eruption and caldera collapse in at least 200 years. After collapse of the Pu'u 'O'o 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 (M w) 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 to M w 4.7 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 Kilauea enabled successful forecasting of hazardous events.
