Onset and evolution of Kilauea's 2018 flank eruption and summit collapse from continuous gravity

Prior to the 2018 lower East Rift Zone (ERZ) eruption and summit collapse of Kilauea Volcano, Hawai'i, continuous gravimeters operated on the vent rims of ongoing eruptions at both the summit and Pu'u 'O'o. These instruments captured the onset of the 2018 lower ERZ eruption and the effects of lava withdrawal from both locales, providing constraints on the timing and style of activity and the physical properties of the lava lakes at both locations. At the summit, combining gravity, lava level, and a three-dimensional model of the vent indicates that the upper similar to 200 m of the lava lake had a density of about 1700 kg m(-3), slightly greater than estimates from 2011-2015 and possibly indicating a gradual densification over time. At Pu'u 'O'o, gravity and vent geometry were used to model both the density and the rate of crater collapse, which was unknown owing to a lack of visual observations. Results suggest the withdrawal of at least 11 x 10(6) m(3) of lava over the course of two hours, and a material density of 1800-1900 k gm(-3). In addition, gravity data at Pu'u 'O'o captured a transient decrease and increase about an hour prior to crater collapse and that was probably related to a small, short-lived fissure eruption on the west flank of the cone and possibly to dike intrusion beneath Pu'u 'O'o. The fissure was the first event in the subsequent cascade that ultimately led to the extrusion of over 1 km(3) of lava from lower ERZ vents, collapse of the summit caldera floor by more than 500 m, and the destruction of over 700 homes and other structures. These results emphasize the importance of continuous gravity in operational monitoring of active volcanoes. Published by Elsevier B.V.

Automated summary

This study utilized continuous gravimeters to monitor the eruption activity of Kilauea Volcano in 2018, providing detailed physical characteristics of lava lakes and data on lava withdrawal, emphasizing the importance of continuous gravity in monitoring active volcanoes.