CHARACTERIZING AND EXPLAINING MILDLY EXPLOSIVE BASALTIC VOLCANISM: EXAMPLES FROM KILAUEA IN 2018 (Invited Presentation)

The eruptions from numerous fissure segments along the lower East Rift Zone (LERZ) of Kilauea in May-August 2018 showed a diverse range of eruptive styles and processes from weak discrete explosions to emergent sustained fountaining. Contrasting styles and intensities occurred simultaneously and from vents often only 10 meters apart. The products of such activity cannot be constrained from the final deposits. However high resolution imagery permits us for the first time to constrain pyroclasts velocity, grain size and shape while still in-flight. We can then derive other critical source terms for modelling such as total mass and in-flight mass eruption rates.

We show that data can be constrained with spatial and temporal resolutions not possible from the in situ deposits. We present here examples of these parameters for the opening phase of eruptions from fissure 8 in the LERZ in May 2018, and contrast them with data from short-lived explosions elsewhere. We also map the transitions between pulsating outgassing (‘puffing”), transient explosions and sustained discharge during the birth of fissure 8.