Central Type Of Eruption

  Central type of eruption is one of the eruption when hot molten magma comes out through the central pipe or several parasite cones either in a very explosive manner or in a quiet manner. If the volcanic eruption would be explosive or quiet manner, it depends on the composition of magma and gasses comes out through the vent.

Hawaiian Explosion:

This type of eruption are very common occurrence on Hawaiian island. Hawaiian eruption form where basic basaltic lavas are exuded regularly, with very little explosive activity and produce flows or lava sheets. Limited explosion sometimes release gas which may create cinder cones, seldom exceeds the height of 300m at central or parasite cone or spatter cones of lava globules up to 100m high resulting fire fountain develops during lava release. Tephra are also thrown to the air only a few hundred metres in some eruption. 

Strombolian Eruption:         

Such volcanoes are named after Stromboli volcano of Lipari island in the Mediterranean sea. This volcanoes are remarkable for its regularity and frequency of basaltic eruptions of mild to moderate explosion. Strombolian eruption congeal the vent which may collapsed or fragmented during the next eruption. At this time debris and bombs of fresh lava are thrown to the air and fall onto the rim, or back into the crater. Fir fountain and luminous eruption clouds are common characteristics of Stromboli.  The bright light of the ejected materials are regularly seen from the ship, called as the ‘Light house of Mediterranean sea’.

Vulcanian Type Of Eruption:

These are named after volcano of Lipari island in the Mediterranean sea. Such volcanoes erupt with great force and intensity. The lavas are so viscous and pasty that they are quickly solidified and hardened between teo eruptions and thus they crust over the volcanic vents. Vulcanian eruptions produce large volumes of fine dust and rock fragments which form many nuees ardentes on the flaks of strato volcanoes.

Visuvious Type Of Eruption:

These are more or less similar to vulcanian and strombolian types of volcanoes. The difference lies only in the intensity of expulsion of lavas and gases. There is extremely violent expuslsion of magma due to enormous volume of explosive gases.

Plinian Eruption :

These are highly explosive, with huge billowing, dense clouds of gas and tephra being thrown upwards to 5-60km above the sea level.  The volume of explosion is usually great enough to disrupt the structure of strato volcano. Thus, crater wall totally destroyed and fragmentation of solidified lavas are common characteristics of these volcanoes. The gases, lavas are released from the crater with velocities of hundred metres per second.
   On the basis of range of magnitudes plinian eruption is useful to distinguish subplinian,plinian and ultraplinian in an ascending order of power, mass of material ejected, altitude to which ejection are carried and area on which they fall. Subplinian are similar to vulcanian and ultraplinian are extremely rare.

Pelean Type:

  These are name after the pelee volcano of Martinique island in the Caribbean sea. These are the most violent and most explosive type of volcanoes. The ejected lavas are most viscous and pasty. Such type of disastrous violent eruptions are named as ‘nuees ardentes’ meaning thereby ‘glowing cloud’ of hot gases, lava etc, coming out of a volcanic eruption.

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