Episodic earthquake mechanisms and intervening seismicity during the 2018 summit collapse at Kilauea caldera
- 1Institute of Earth Sciences, Lausanne, Switzerland (celso.alvizuri@unil.ch)
- 2Department of Earth Science, University of California Santa Barbara
- 3Department of Earth Sciences, University of Hawaii at Manoa Honolulu
The 2018 rift zone eruption of Kilauea volcano was accompanied by a remarkable and episodic collapse of its summit. Between May-August the eruption and collapse sequence included over 70,000 earthquakes (M≥0) and 54 major earthquakes (M≥5). We analyzed the seismicity in the Kilauea summit region and estimated seismic full moment tensors with their uncertainties for the 54 M≥5 events. These events occurred at almost daily intervals and were accompanied by intense seismicity which was concentrated between 0-3 km depths beneath the Halema‘uma‘u pit crater. The hypocenters reveal partial elliptical patterns (map view) that migrated downward by ∼200 m. The moment tensors reveal remarkably consistent mechanisms, with negative isotropic source types and localized uncertainties, and vertical P-axis orientations. From the moment tensors we derived Poisson’s ratios which are variable (ν = 0.1 − 0.3) for the first half of the collapse events and converged to ν ∼ 0.28 from June 26 onward.
How to cite: Alvizuri, C., Matoza, R., and Okubo, P.: Episodic earthquake mechanisms and intervening seismicity during the 2018 summit collapse at Kilauea caldera , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14433, https://doi.org/10.5194/egusphere-egu21-14433, 2021.