Impulsive Volcanic Plumes Generate Volcanic Lightning and Vent Discharges: A Statistical Analysis of Sakurajima Volcano in 2015

Smith, Cassandra M.; Gaudin, Damien; Eaton, Alexa R. van; Behnke, Sonja A.; Reader, Steven; Thomas, Ronald J.; Edens, Harald; McNutt, Stephen R. and Cimarelli, Corrado (2021): Impulsive Volcanic Plumes Generate Volcanic Lightning and Vent Discharges: A Statistical Analysis of Sakurajima Volcano in 2015. In: Geophysical Research Letters, Vol. 48, No. 11, e2020GL092323

Abstract

The origin of electrical activity accompanying volcanic ash plumes is an area of heightened interest in volcanology. However, it is unclear how intense an eruption needs to be to produce lightning flashes as opposed to vent discharges, which represent the smallest scale of electrical activity. This study targets 97 carefully monitored plumes <3 km high from Sakurajima volcano in Japan, from June 1 to 7, 2015. We use multiparametric measurements from sensors including a nine-station lightning mapping array and an infrared camera to characterize plume ascent. Findings demonstrate that the impulsive, high velocity plumes (>55 m/s) were most likely to create vent discharges, whereas lightning flashes occurred in plumes with high volume flux. We identified conditions where volcanic lightning occurred without detectable vent discharges, highlighting their independent source mechanisms. Our results imply that plume dynamics govern the charging for volcanic lightning, while the characteristics of the source explosion control vent discharges.

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences
• Subjects: 500 Science > 550 Earth sciences and geology
• ISSN: 0094-8276
• Language: English