Monitoring the Development of Volcanic Eruptions through Volcanic Lightning: A Statistical Investigation into Volcanic Electrification and Seismic/Infrasound Signals

A goal for the adoption of volcanic lightning to volcanic monitoring systems is to understand what the presence of volcanic lightning/electrification can tell us about the ongoing eruption dynamics at the volcano. We used a lightning mapping array (LMA) with a two-array network of (2) seismic and (6) infrasound sensors deployed at Sakurajima Volcano, Japan from 29 May - 07 June 2015 to examine this relationship. Through multi-variable statistical analysis, using logistic and linear models, we have determined the relationships between commonly recorded seismic and infrasound measurements and quantified metrics of volcanic electrification. Advancements in this work over the past year have expanded our understanding of these complex relationships. By examining over 1500 total events, of which ~600 had measured electrical activity, we are able to show how increases in the explosive nature of the eruption effect the resulting electrification of the volcanic plume. Results show specifically that the amount of energy partitioned into the air as infrasound has a significant relationship with the presence of continual radio frequency signals and the presence of lightning flashes. Additionally, the interaction between seismic and infrasound signals is statistically significant for the overall duration of electrical activity and the total number of electrical sources detected by the LMA. These statistical models will help create a base for understanding how recorded volcanic lightning may be used to monitor volcanic eruptions by helping estimate eruption parameters