Flow channel in a prehistoric flow on Etna's
south flank.
Partially drained flow channel in a (probably) prehistoric lava flow, about
1 km east of Rifugio Sapienza, photographed on 24 May 1998. Width of the
channel at bottom is about 1 m.
Active and drained flow channels, May 1999.
Left: Lava flowing from an "ephemeral" effusive vent (that
is, a vent that is fed by a lava tube and is not a true eruption vent)
into a well-defined channel about 0.8-1 m wide, on the western wall
of Valle del Bove, 12 May 1999. Right: Drained lava channel after supply
to the effusive vent at its head (in the foreground) was suddenly cut
off. Depth of the channel (about 1.2-1.5 m) is greater than its width
(0.7-1 m). This photo was taken in about the same area as left image,
but one week later.