Date: March 2009
What is a Strombolian volcano?
A Strombolian volcano is specifically a volcano in the Stromboli, Italy.
Strombolian eruptions are low level or mild eruptions, usually with lava bombs
of altitudes well under 100meters. In general, they are of small volume with
occasional violence. They are minimally violent with small explosions on the
order of minutes.
Nathan A. Unterman
The United States Geological Survey defines strombolian-type eruptions as a type of
volcanic eruption characterized by jetting clots or fountains of fluid, basaltic lava
from a central crater.
The word strombolian is derived from the volcano Stromboli, one of the Aeolian Islands
north of Sicily. Stromboli has been almost continuously in eruption for at least the
past 2,400 years. Other volcanoes that often exhibit strombolian activity include
Etna (Italy), Pacaya (Guatemala), and Erebus (Antarctica).
Strombolian eruptions are characterized by the intermittent explosion or fountaining
of basaltic lava from a single vent or crater. Each episode is caused by the release
of volcanic gases, and they typically occur every few minutes or so, sometimes
rhythmically and sometimes irregularly. The lava fragments generally consist of
partially molten volcanic bombs that become rounded as they fly through the air.
The Volcanic Explosivity Index (VEI) is a measure of the magnitude of volcanic
eruptions. The VEI ranges from 1 (small) to 8 (large) and strombolian-type eruptions
are moderately explosive range from VEI 1 to VEI 3. For comparison, the 1980 eruption
of Mt. St. Helens just barely made a VEI 5 rating.
I think that Big Ben is the only active volcano in Australia, but, what do you think
would happen if the Tweed Volcano Group erupted with a VEI equal to 8?
Leslie Kanat, Ph.D.
Professor of Geology
Department of Environmental Sciences
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Update: June 2012