Geoscience Reference
In-Depth Information
While volcanic activity provided a natural source for the
imaginative myths of the ancient Greeks and Romans, it also drove
early philosophers to attempt to explain what was going on so
violently out of sight. Discussing the four great rivers of the earth,
Plato writes in
Phaedo
of one of them, Pyriphlegethon, which
pours into a huge region all ablaze with fire, and forms a
lake larger than our own sea [the Mediterranean], boiling
with water and mud; from there it proceeds in a circle,
turbid and muddy, and coiling about within the earth it
reaches the borders of the Acherusian Lake, amongst other
places, but does not mingle with its water; then after repeated
coiling underground, it discharges lower down in Tartarus;
this is the river they name Pyriphlegethon, and it is from
this that the lava-streams blast fragments up at various
points upon the earth.7
Plato described the formation of lava or obsidian: 'Some-
times when the earth has melted because of the fire, and then
cooled again, a black-coloured stone is formed.' Being cast into
Pyriphlegethon is the fate that awaits 'those who have outraged
their parents' - so watch out, kids. The Roman hero of Virgil's
Aeneid
, Aeneas, was shocked when visiting the Underworld to
find Pyriphlegethon, 'sweeping round with a current of white-hot
flames and boulders that spun and roared'.8
The Greek dramatist Aeschylus may have witnessed the 479
bc eruption of Etna, or at least some smoke and rumbling,
when he visited the settlements of Magna Graecia in Sicily in
the 470s. Indeed he died there in 456/455 when, according to
legend, an eagle dropped a tortoise on his head from a great
height. A contemporary of Aeschylus, the lyric poet Pindar,
described Etna, 'from whose depths belch forth holiest springs
of unapproachable fire'.9
The first recorded student of Etna was the fifth-century bc
Greek philosopher Empedocles, who formulated the idea of
the four elements, Earth, Air, Fire and Water. However, he used
the mountain not as a laboratory to investigate the workings of
