New
satellite pictures from NASA show the dark brown smoke and
ash plume originating from Mt. Etna stretching for hundreds
of miles over the Mediterranean Sea.
The Moderate Resolution
Imaging Spectroradiometer (MODIS) instrument on NASA’s Terra
satellite captured a spectacular true-color image of the eruption
October 29, 2002. A long, grayish-brown plume of ash and smoke
is streaming southward from the volcano.
Located
on the island of Sicily, Etna is one of the most studied volcanoes
on Earth. Just last summer, French scientists reported that
Etna appeared to be undergoing a gradual shift from being
a "hot spot" volcano, in which magma wells up from
within the Earth, to an "island arc" volcano, in
which magma is produced from the collision of tectonic plates.
In keeping with that idea, this most recent eruption occurred
after a series of hundreds of small earthquakes affected eastern
Sicily. Unfortunately for area residents, the transition from
a hot-spot volcano to a island-arc volcano signals the potential
for greater danger, as the latter produces explosive, as opposed
to oozing, eruptions.
