MAGAZINE0 2 | 9
ERUPTION POWER
Geologists measure volcano eruption
power by means of the Volcanic
Explosivity Index (VEI). The index
compares the violence of different
eruptions based on the ash column
height, volume of emitted material and
eruption time. The index ranges from 0
to 8. The first value indicates a non-
explosive eruption, while the last one
refers to the so-called “mega colossal
eruption”.
Pyroclast is the designation for solid
rock fragments expelled to the air by a
volcano eruption. Between April 22 and
23, 2015, Calbuco volcano in Chile, was
classified as IEV 4, expelling 1.1 km3 of
pyroclasts.
It is believed that the Yellowstone
volcano, in the USA, holds the record
of the history’s largest eruption, with
an emission of 1,000 km3 of pyroclasts,
which classifies it as IEV8. Fortunately,
this occurred 640,000 years ago.VOLUME OF EMITTED
PYROCLASTS
IEV0.001 km^30.1 km^30.01 km^31 km^310 km^3- 000001 km^3
100 km^30 1 2 3 4 5 6 7DESTRUCTIVE CLOUDS
An aircraft encountering ashes of volcanic clouds
in its route will suffer extended and potentially
catastrophic damages.
Ash columns expelled by volcanoes carry tons of
micro-particles of obsidians, rocks and silicates.
The contact of these materials with an aircraft is
potentially destructive, acting like a powerful sander,
which, in seconds, is able to destroy an engine.
In most of eruptions are found large quantities of
silicon dioxide (SiO2), sodium carbonate (Na2CO3)
and calcium carbonate (CaCO3). The combination of
these three materials is known as glass.
The clouds created by volcanoes contain gigantic
amounts of sulfur dioxide, hydrogen sulfide and
hydrogen chloride, all known to be powerful acids.
100,000 CANCELLED
FLIGHTS
In 2010, the ashes of the Icelandic volcano,
with an unpronounceable name for many
people, Eyjafjallajokull, led to the cancellation
of at least 100,000 flights in Europe. It was
the greatest disturbance caused to date by
an eruption. Later, authorities considered the
cancellations to be an exaggeration.
Even so, during the Eyjafjallajokull eruption,
an F-16 of NATO suffered great damages when
passing near the ashes. Large quantities of
volcanic glass were found inside the engine.