- Volcanoes
Types of volcanic eruptions
Lava and other volcanic matter are expelled in many distinctive ways. These ways were named after how some well-known volcanoes gave out lava. These are as follows:
Strombolian eruption:
In this eruption, clots of molten lava burst from the vent (summit) into the sky. It looks like fireworks, displaying luminous arcs or fire. It was observed during an eruption of the Iruzu Volcano in Costa Rica in 1965.
Vulcanian eruption:
This involves the expulsion of ash-laden gas from the peak, forming whitish clouds of ash at the top of the cone. This type was observed in an eruption of Parícutinin 1947.
Vesuvian eruption:
Here, ash-laden gas gushes out violently, forming thick cauliflower shapes of ash-clouds. It was observed in the eruption of Mount Vesuvius in Italy, in the year 79 A.D
Peléan / Nuée Ardente eruption:
Here, incandescent lava, together with ash and gas is blown out from the crater, vertically upwards and falling in again. The spilling of glowing avalanches along the slopes can be very deadly and destructive. This type of eruption occurred on the Mayon Volcano in the Philippines in 1968
Hawaiian eruption:
As observed with Mauna Loa Volcano in Hawaii, 1950, this eruption occurs along a fracture (linear vent) with burning lava sprouting from the fracture. It can also occur in a central vent, in which case incandescent lava gushes out in the form of a fountain.
Phreatic (say free-a-tic) eruption:
This type does not involve the outpour of lava but is usually set off when cold ground or water comes into contact with hot molten matter. The resulting steam that is forced upwards usually contains the débris of surface rocks. No new magma erupts.
Plinian eruption:
This eruption type ejects massive viscous lava, with gases and ash, miles into the air. The light nature of the lava is carried miles away by the wind action and tends to spread many miles from the eruption point.