Geoscience Reference
In-Depth Information
Image not available - no digital rights
to flood into the valley beneath. There were many casualties
and much damage to buildings, crops and livelihoods. The artist
Halut was present during the 1977 eruption, and was among
the many refugees.
Vesuvius, whose lava has a relatively high silica content,
produces slow-flowing pyroclastics, the hot mixture of materials
erupted from the interior. This gradualism has the tendency to
cause the eruptions to be more powerful, and to eject to greater
altitudes, as happened during the ad 79 eruption, witnessed and
described by Pliny the Younger. In that event a column of fiery
lava drove skywards for three or more kilometres. The thicker
the lava, as at Vesuvius, the longer the eruption column holds its
shape; the thinner it is, on the other hand, the more it spatters
and fountains, as is characteristic of the Hawaiian volcanoes.
The author Norman Lewis was present at the 1944 eruption of
Vesuvius: 'At the time of my arrival the lava was pushing its way
very quietly down the main street . . . I had been prepared for
rivers of fire, but there was no fire and no burning anywhere -
Lava in Hawaii pouring
into the oceans.
