The full range of effects of strong volcanic eruptions on the electrical characteristics of the atmosphere is not yet fully understood. On April 10, 2023, the largest in recent decades eruption of the Shiveluch volcano in Kamchatka occurred. At the same time, a sharp increase in electron concentration was observed in the F layer of the ionosphere above the volcano. Simultaneously, at a distance of 450 km from the volcano, an intense anomaly was observed in the vertical component of the electric field potential gradient in the surface atmosphere. At this distance, the anomaly could not have been caused by a space charge of volcanic ash. The article examines the atmospheric-electrical effects of a volcanic eruption and proposes a physical mechanism for these phenomena. The formation of strong electric field splash as result of volcano eruption was confirmed by the consecutive Shiveluch volcano eruption on 18 August 2024.