A subaerial eruption is any sort of

volcanic eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are ...

that occurs on the Earth's surface, or in the open air 'under the air', and not underwater or underground. They generally produce

pyroclastic flow A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...

lava fountain Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

s, and lava flows, which are commonly classified in different subaerial eruption types, including Plinian, Peléan, and

Hawaiian eruption A Hawaiian eruption is a type of volcanic eruption where lava flows from the vent in a relatively gentle, low level eruption; it is so named because it is characteristic of Hawaiian volcanoes. Typically they are effusive eruptions, with basaltic ...

s.Hawaii's Volcanoes Revealed
/ref> Subaerial eruptions contrast with subaqueous, submarine and

subglacial eruption Subglacial eruptions, those of ice-covered volcanoes, result in the interaction of magma with ice and snow, leading to meltwater formation, jökulhlaups, and lahars. Flooding associated with meltwater is a significant hazard in some volc ...

s which all originate below differing forms of a water surface.

References

Volcanic eruption types {{Types of volcanic eruptions