Europe 2017 - Day 5. Around Mount Etna

We have a lot of plans for today, so we stated a firm departure time of 9:30 am, and working in our best Sicilian time, we started at about 10:15 am. Boris was our guide, and he and his family wanted to show us their favorite places around the volcano. Boris is married to Catherine, and they have a single daughter, Ida, who is 12 years old and thus the perfect model for photographs. We were going around the mountain clockwise, starting in the south at our hotel, the Hotel Corsaro.

Rather than describe the different stops, let me see if I can summarize for you all that I learned today about Mount Etna. It is a large volcano, in the same league as Mount Shasta or the Nevado de Toluca, but it is largely basaltic in composition. The bulk of the magma erupted can be described as a mildly alkaline basalt, or hawaiite, although in some instances it has erupted magmas that could be better described as mugearites (a mildly alkaline basaltic andesite) or benmoreites (a mildly alkaline andesite). Being a large volcano, it is subject to gravitational spreading, which expresses itself as extensional rifts where many of the eruptions form parasitic cones. There are maybe 50 of such cones along the flanks of the volcano, and just by looking on the topographic map I would say there are a south rift, a western rift, and a northeastern rift.  Boris tried to explain to us the tectonic setting, but it is not easy to grasp. On one hand you have the African plate pushing north, and apparently causing a subduction zone to form under Greece and southern Italy. To the west, the African continental plate has already met the continental crust of the European sub-plate, so subduction cannot take place. It is at the odd junction of these two regimes that Etna is located, perhaps the result of a tear end of the Greek-Italian subduction zone causing mantle decompression, partial melting, and alkaline basalt volcanism.

The puzzle of geology aside, the rift zones are decked with beautiful forests, whereas the slopes away from them are covered by young and spiney lava flows (aa lavas being a lot more abundant than pahoehoe lavas). Volcanic activity in the area seems to have started half a million years ago, but most of the volcanic edifice was built in the last 100,000 years, and most of the surface lava flows are variously dated to the Roman era, the Middle Ages, and of course historic and quite recent times.

Throughout our outing the summit loomed above us, with its continuous plume of steam that eventually coalesces to form clouds.

On our way we passed many beautiful Sicilian towns, perched precariously on top of a cinder cone or on the sides of the rifts. We made sure to make many stops along the way, to check “refreshment stations” because the day was pretty warm (although the breeze and the shade of the many trees made it bearable). But Boris had saved the best for last, and as the afternoon got on its way on the north side of the volcano he led us to the Rio Alcantara, where we found a shady cleft in the basalts with one of the best swimming holes you can imagine. The water was deliciously cool and we enjoyed ourselves tremendously.