NEW INSIGHTS INTO LAVA FLOW DYNAMICS AND HAZARDS FROM THE 2018 ERUPTION OF KĪLAUEA, HAWAIʻI (Invited Presentation)

The 2018 lower East Rift Zone eruption of Kīlauea volcano, Hawaiʻi, was the most destructive Hawaiian eruption in the past 200 years and posed a significant challenge for monitoring and forecasting the extensive lava flow hazards over time. Documentation of the lava flow-field emplacement in unprecedented detail with ground-based observations and airborne remote sensing informed eruption response. These novel datasets are now yielding new insights into lava flow dynamics and hazard forecasting. This talk will review some of these observations, particularly from uncrewed aircraft systems (UAS) and airborne lidar data, and discuss syn-eruptive and post-eruptive analyses for hazard assessment and investigations of lava flow behavior. An integrated time series of topographic data and UAS lava channel video captured long-term and short-term changes in lava effusion rate and flow morphology, improving our understanding of the controls, evolution, and implications of effusion rate and terrain on lava flow emplacement. Varying effusion rates allowed characterization of undular hydraulic jumps in the proximal lava channel, verifying the application of hydraulic theory to lava, and providing a new tool to better measure effusion rates by analyzing these structures. Remote sensing of flow-field evolution shows that combined forcing from fluctuating effusion with topographic variation and rheologic change caused secondary flow widening from overflows, ooze-outs, and levee failures with profound hazard impacts. These new data, models, and interpretations are broadening our knowledge of the complex dynamics of lava flow fields and are informing tools and planning for improved monitoring and hazard assessment in future eruptive crises.