EGU21-14433
https://doi.org/10.5194/egusphere-egu21-14433
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Episodic earthquake mechanisms and intervening seismicity during the 2018 summit collapse at Kilauea caldera 

Celso Alvizuri1, Robin Matoza2, and Paul Okubo3
Celso Alvizuri et al.
  • 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.

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