<p>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&#8805;0) and 54 major earthquakes (M&#8805;5). We analyzed the seismicity in the Kilauea summit region and estimated seismic full moment tensors with their uncertainties for the 54 M&#8805;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&#8216;uma&#8216;u pit crater. The hypocenters reveal partial elliptical patterns (map view) that migrated downward by &#8764;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&#8217;s ratios which are variable (&#957; = 0.1 &#8722; 0.3) for the first half of the collapse events and converged to &#957; &#8764; 0.28 from June 26 onward.</p>
Subdivision of seismicity beneath the summit region of Kilauea volcano: Implication for the preparation process of the 2018 eruption