Multidisciplinary investigation on a lava fountain preceding a flank eruption: The 10 May 2008 Etna case

A multidisciplinary approach integrating a wide data set ranging from bulk rock compositions of the
erupted products to volcanic tremor, long‐period events, and tilt and gravity signals is used to investigate
the source depth and magma dynamics of the 10 May 2008 lava fountain at Southeast crater (SEC) of
Mount Etna. The investigation was undertaken in the framework of the previous 2007 explosive activity
as well as the subsequent effusive eruption beginning 13 May 2008 and lasting up to July 2009. All the
data concur in indicating that the 10 May lava fountain was generated by the fragmentation of a foam layer
trapped at the top of a shallow reservoir, about 1500–1700 m below the summit of SEC. The shift from the
episodic strombolian/lava fountain activity occurring in 2007 at SEC to the more powerful 10 May 2008
lava fountain is explained by the intrusion of a new more primitive magma into the shallow reservoir.
Data also indicate that an attempted magma intrusion east of the summit area occurred during the
10 May fire fountain. This event caused the fracturing and weakening of the surrounding rocks and
created a preferential pathway for the penetration of the magma that, only 3 days later, started to feed
the 2008–2009 effusive eruption.