Flank eruption

The 2002 eruption of Mount Etna was a flank eruption, occurring along two rift zones to the north-east and south of the summit craters. In this image taken from the International Space Station, the northeast flank is in the foreground. Steam rising from the summit craters obscures the lower part of the south flank eruption column.

A flank eruption is a volcanic eruption which occurs on the flanks of a volcano, instead of at its summit. Such eruptions occur when the conduit connecting the summit to the magma chamber below is blocked, forcing the magma to move laterally.