In this article types of eruption will be used to refer to the mechanism causing the eruption. The style of eruption will be used to describe subcategories of eruption, which have the same eruptive mechanism. For example strombolian and vulcanian are two eruptive styles, but they are the same type. The styles of volcanic eruption are often named after famous volcanoes where characteristic behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during an interval of activity—others may display an entire sequence of types.

Types

There are three very, very, very hot, hot, hot,hot mechanisms of very, very hot ash formation: very, very hot gas release under very hot decompression causing very hot magmatic eruptions; very hot thermal contraction from chilling on contact with water causing phreatomagmatic eruptions and ejection entrained particles during steam eruptions causing phreatic eruptions (Heiken & Wholtez 1985.)

Magmatic Eruptions

Magmatic Eruptions produce juvenile clasts during explosive decompression from gas release. They range in size from the relatively small fire fountains on Hawaii to >30 km Ultra Plinian eruption columns, bigger than the eruption that buried Pompeii. (Heiken & Wohletz 1985)

Strombolian

main: Strombolian eruption Strombolian eruptions are named because of activity of Stromboli in Sicily. They are characterised by huge clots of molten lava bursting from the summit crater to form luminous arcs through the sky. Collecting on the flanks of the cone, lava clots combine to stream down the slopes in fiery rivulets. The explosions are driven by bursts of gas slugs that rise faster than surrounding magma.1

Vulcanian

main: Vulcanian eruption Vulcanian eruptions are named after Vulcano, following Giuseppe Mercalli's observations of its 1888-1890 eruptions. Another example was the eruption of Parícutin in 1947. They are characterised by a dense cloud of ash-laden gas exploding from the crater and rising high above the peak. Steaming ash forms a whitish cloud near the upper level of the cone

Peléan

main: Peléan eruption In a Peléan eruption or nuée ardente (glowing cloud) eruption, such as occurred on the Mayon Volcano in the Philippines in 1968, a large amount of gas, smoke, dust, ash, and lava fragments are blown out of a central crater, fall back, and form avalanches that move downslope at speeds as great as 160 km per hour. Such eruptive activity can cause great destruction and loss of life if it occurs in populated areas, as demonstrated by the devastation of Saint-Pierre during the 1902 eruption of Mont Pelée on Martinique, Lesser Antilles.

Hawaiian