It is a phenomenon that is also known as volcanic lightning, because gigantic electrical discharges are produced like those of conventional storms , but in the plume – the gas column of a volcano when it erupts.
As José Miguel Viñas, physicist, scientific communicator and consultant to the World Meteorological Organization (WMO) explains, “these discharges are formed by a mechanism in some way analogous to that which takes place in storm clouds, in cumulonimbus clouds. If in these it is the friction between the hailstones in the upper part of these cumulonimbus that separates the electric charge and gives rise to these discharges, in the volcanic cloud the elements that escape from the crater, the pyroclasts and the volcanic ash, enter into friction which also causes the separation of electrical charge and the appearance of lightning ”.
In any volcano
Dirty storms, therefore, are a phenomenon that can occur in any erupting volcano. The first recorded observation is from the year 79, when the Roman historian Pliny the Younger described the eruption of Mount Vesuvius. It was also there that the first scientific studies of dirty storms were carried out, carried out by Professor Luigi Palmieri during the eruptions of 1858, 1861, 1868 and 1872, which often included lightning activity.
An investigation published in 2008, in the Volcanology Bulletin, pointed out that between 27% and 35% of the eruptions are accompanied by these flashes. In this sense, spectacular dirty storms have been photographed in various parts of the world, such as the Chaitén volcano in Chile; in Colima, from Mexico; on Mount Augustine, Alaska; in the Eyjafjallajökull, of Iceland; and on Etna, from Sicily.
