Types of Volcanic Eruptions

As we know, there are different kinds of volcanoes (strato, conder cone, shield,). So today instead, i'll be discussing the type of volcanic ERUPTIONS. Very different things.

Hawaiian

Most often seen in Shield volcanoes, especially Kilauea and Mauna Loa (hence the name), Hawaiian eruptions

are more subtle with a fluid Basaltic lava flow. The Basaltic magma is becuase of the low silica content in that specific area as well as a low water content in the ground. Before lava flows are formed, the lava will be shot into the air at great heights from the vent. These are called 'fire fountains'.

Hawaiian eruptions sometimes occur on fissure vents (vents were eruptions arent needed for lava to show up). Very little ash is realeased in these eruptions.

Strombolian

These eruptions are alot more exciting than Hawaiian ones in my opinion in terms of thier activity. Like Hawiian

eruptions, Stombolian eruptions realease fluid Basaltic lava and produce small amounts of ash. But the difference between the two is that Strombolian eruptions are caused by gas bubbles forming in magma, and when they arrive at the Earth's surface, they explode and cause lava to be shot ou tin every direction, throwing glowing cinder, and volcanic bombs around the place. The most famous Stombolian eruptions happen on the island of Stromboli off the coast of Italy, where these eruptions occur very often. Eruptions dont last very long.

Vulcanian

Like Stomboli, Vulcanian eruptions are produced by the build up of gas in magma. But instead of Basaltic Lava, these eruptions more Andesitic, usually meaning they are more explosive. Vulcanian eruptions will normally have lots of ash being spwed out, and pyroclastic flows. Though short lasting, eruptions will be very powerful with large amounts of rock material being realeased from the volcano.

Plinian

"And the walls came tumbling down, on the city that we love. Gray clouds rolled over the hills bring darkness

from above" - Pompeii by Bastille

Yup. The famous eruption of Mount Vesuvius was a Plinian eruption. Already from knowledge on the destruction of Pompeii we can guess the intensity and danger of a Plinian eruption. Named after Pliny the Younger, a magistrate in Anchient Rome whom witnessed first hand the eruption of Vesuvius in 79 AD, Plianian eruptions can create ash clouds up to 55 km tall. Pliny the Younger described the ash as "a pine tree, for it shot up to a great height in the form of a very tall trunk, which spread itself out at the top into a sort of branches". They have extermely large amounts of gas and ash realeased in pyroclastic flows. Lava is highly very vicous and explosive, usually composed from Rhyolitic lava which makes it so thick.

Pelean

Pelean eruptions are named after Mount Pelee, Martinique. They will not have a large lava flow, but that doesnt mean they arent deadly. The thing that make Pelean eruptions, along with other types of eruptions are the pyroclastic flows. And Pelean eruptions are mainly just that. Hot rock, ash, and gas speeding at extreme speeds straight towards people are what makes volcanoes so dangerous.

Phreatomagmatic

When lava reaches a surface with water surrounding it, the eruption will result in a Phreatomagmatic eruptions. There are 3 types of these eruptions:

A Surtseyan is the eruption when lava come in contact with SHALLOW water and are like Strombolian eruptions, but in the water. They can create pyroclastics surges, which unlike flows, can travel over hills for they are less dense and con

sist of more gas. (Its name comes from the famous Surtsey volcano, Iceland)

Submarine eruptions applies to ones that occur completely underwater. They release basaltic lava, and because it is under water, many interesting features are formed by it, for example pillow lava. Some occur on hotspots and are what form island chains like Hawaii.

Subglacial eruptions, as you may guess from the name, are those that take place underneath ice, and will melt ice, creating risks like possible floods and lahars.

Phreatic

I think ive mentioned these before, but just to recap. Phreatic eruptions are the

heating of water from magma to the point where it turns to steam and is shot out of vents. Sometimes, Phreatic eruptions can happen before a more severe eruption. For example, the 1980 eruption of Mt St Helens, Washington. Also Krakatoa's humoungous bang was the phreatic explosions that was heard world wide.

Thanks for reading, and sorry for not writing in a long time. Ive been slaving away at exams and revision.

Live Long and Prospere!

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