Plinian and Subplinian Eruptions

In modern volcanology, the term “plinian” encompasses explosive eruptions characterized by the quasi-steady, hours-long, high-speed discharge into the atmosphere of a high-temperature, multiphase mixture (gas, solid, and liquid particles), forming a buoyant vertical column that reaches heights of tens of kilometers . After having attained its maximum height, the column eventually spreads laterally into an “umbrella” cloud, which maintains its identity for hundreds of kilometers. Conversely, when buoyancy of the erupting mixture is not achieved, the basal part of the column collapses and forms a sustained, ground-hugging cloud of hot gases and pyroclasts, which disperse around the volcano