Volcanic Eruptions – The most common type of volcanic eruption occurs when magma is released from a volcanic vent. Eruptions can be effusive, where lava flows like a thick, sticky liquid, or explosive, where fragmented lava explodes out of a vent. In the explosive type of eruptions, the fragmented rock may also be surrounded by ash and gases. Volcanologists typically eruptions into different types. Some of these types are named for particular volcanoes where the type of eruption is most common. Here are some of the most common classifications:
Hawaiian Eruptions – In a Hawaiian eruption, fluid basaltic lava is thrown into the air in jets from vents at the summit or on the flank of a volcano. The jets can last for hours or even days. Hawaiian eruptions get their name from the Kilauea volcano on the Big Island of Hawaii.
Strombolian Eruption –Strombolian eruptions are distinct bursts of fluid lava from the mouth of a magma-filled summit conduit. The explosions usually occur every few minutes at regular or irregular intervals. Strombolian eruptions are often associated with small lava lakes, which can build up in the conduits of volcanoes.
Vulcanian Eruption –A Vulcanian eruption is a short, violent, relatively small explosion of viscous magma. This type of eruption results from the fragmentation and explosion of a plug of lava in a volcanic conduit, or from the rupture of a lava dome.
Plinian Eruption – The largest and most violent of all the types of volcanic eruptions are Plinian eruptions. They are caused by the fragmentation of gassy magma, and are usually associated with very viscous magmas.
Lava Domes – Lava domes form when very viscous, rubbly lava is squeezed out of a vent without exploding. The lava piles up into a dome, which may grow by inflating from the inside or by squeezing out lobes of lava.