(Fig. 2.16) Vulcanian Eruption.
Vulcanian eruptions burst into life suddenly after a dormant period. They are similiar to hydrovolcanic activity.
Vulcanian eruptions begin with a violent, noisy explosion. Afterwards fragments of magma are expelled with loud bangs.
Vulcanian eruptions give off much gas as well as ash, cinders and pumice. Ash and pumice are blown away from the vent which may result in rather small cones (350m to 600m high). Vulcanian eruptions can last, with long intervals of repose, for several millennia.
The Vulcanian type of eruption was discovered from studies of the activity, between 2 August 1888 and 22 March 1890, of Fossa cone at Vulcano in the Aeolian Islands, Italy.