Witness of Mount Etna eruption

by Antonio Capponi and Johannes Thun

The Volcanic Processes Field Course on Mt Etna, Sicily, was carried out entirely in the field, developing an understanding of many of the complex processes on the surface and beneath volcanoes. We visited many different localities like lava flows, lava tubes, several vents and dikes, exceptionally large ejects and some Lapilli deposits from the 122 B.C. Plinian eruption. The lecturers Mike James and Steve Lane put a special focus on lava flows and we studied their features on different scales, from the composition and structure up to geometrical properties. We then discussed the relation of these to internal and external processes like for example effusion rate, changes in composition, cooling, topography etc.

Furthermore we were lucky enough to witness the changes of activity during the 10th eruptive episode from the New SE Crater, from the initial phases until its climax on our last day in the field.
The activity started 9th April from the New SE crater with occasional explosive ash emissions, producing relative small ash plumes. The time interval between the explosions initially was up to a couple of hours but kept decreasing while the activity gradually intensified throughout 9th and 10th April.

On 11th April, after this first phase of “vent cleaning”, the activity was characterized by Strombolian eruptions every few seconds without visible emission from our position and producing strong acoustic emissions. And this was only the prelude for the paroxysm…
These strong Strombolian-type explosions continued all day until late in the afternoon (and we were lucky enough to see a beautiful smoke ring from the vent), when the explosions started to produce jets of pyroclasts and small ash emissions and a small lava flow started to flow from the vent. The activity increased over the next hours and entered in the lava fountaining phase at around dinner time. Naturally we decided to give up a (free) pizza in order to witness the fireworks! The fountaining continued all night and the explosions were intense, with jets of variable height.

On 12th April the activity changed to a dense ash plume and in the morning there was also a small collapse of the vent that triggered a small pyroclastic flow! During this phase, a large plume, mainly steam and other gases, was produced and moved toward E-SE with a constant column pushing up; there were several explosions every few minutes with strong ash emissions and ejection of some nice bombs. The activity started to decrease slowly until it ended in the afternoon.
For most of the students this was the first time on Etna. Some of us have been there several times but always unlucky… This time, Etna decided to give us a great show! The spectacular views, the hands-on study and discussions in the field, a good mix of motivated people with different backgrounds and last but not least the amazing food and wine of Sicily made this course not only valuable but also a great personal experience for us!

For more photos, visit the “official” album created by Mike James and Steve Lane for the campus