A Characteristic Electrostatic Structure of Eruptive Plumes Emitted by Large Explosive Eruptions of Shiveluch and Bezymianny Volcanoes, Kamchatka

This paper presents an analysis of recorded variations (anomalies) in the potential gradient of electrical field in the atmosphere caused by the propagation of eruption plumes discharged by eruptions of Shiveluch and Bezymianny volcanoes in Kamchatka. The anomalies were recorded at various distances from eruption centers and under different conditions of atmospheric stratification. These conditions have enabled us to show that the eruption plumes of Shiveluch and Bezymianny possessed a 3D electrostatic structure that is consistent with a known phenomenological model derived on the basis of surveys conducted on various volcanoes worldwide. According to this model, the top of an eruption plume contains a positive volumetric electrostatic charge, while the respective charges are negative in the middle, and positive in the lower part of the plume.