FTI.2 | Somma-Vesuvio volcanic history and impact of the 79 AD eruption in archaeological excavations
The Somma-Vesuvio is built up from an older volcano, Mt. Somma, truncated by a summit caldera, and a more recent cone, Vesuvio, within the caldera. Mt Somma consists of a pile of thin lava flows interbedded with spatter and cinder, cut by a nested, poly-phased caldera structure formed by several collapses related to the main explosive eruptions. The first plinian event, the Pomici di Base eruption (around 20 ka), was followed by three other plinian events, each preceded by long repose periods: Mercato Pumice eruption (8.0 ka), Avellino Pumice eruption (3.9 ka), and Pompeii Pumice eruption (A.D. 79). The Vesuvio cone began to form after A.D. 79, growing discontinuously (with minor summit collapses) during periods of open conduit activity. High- intensity, explosive eruptions sporadically occurred, the two largest being the subplinian events of A.D. 472 (also known as the Pollena eruption) and A.D. 1631. The most recent period (1631-1944) was characterised by lava effusions and semi-persistent, mild explosive activity (small lava fountains, gases and vapour emission from the crater), interrupted by pauses lasting from months to a maximum of seven years.
An introduction to the geology and the volcanological evolution of the volcano will be possible along an itinerary starting from Napoli to the summit of Mt Vesuvio, driving along the southern slopes of Somma-Vesuvio and inside the Mt Somma caldera. On the top of the volcano the view of the present crater wFilol tgoivdei SatenfaonoppBorarntcuanity to describe last eruption of Vesuvio in 1944 and the evolution of the crater after the 1906 eruption. Here, we can take in the wonderful view of the Vesuvio surroundings and shed light on the physical and socio- economical features linked to the volcano activities. At an elevation of 609 m a.s.l.- is situated the Osservatorio Vesuviano, the oldest volcano observatory in the world, founded in 1841 by King Ferdinand II of Bourbon. The historical building of the Osservatorio Vesuviano, today hosts an information centre on volcanic hazards and risk and represents the perfect site to discuss future eruptive scenarios and the emergency plan for the Vesuvian area. The itinerary will be completed by a visit to one the main archaeological excavation sites, the Villa di Poppea in Oplontis, the Herculaneum and the Pompei excavations. During the visit to the sites, destroyed by the A.D. 79 Pompeii eruption, we will address the main problems related to Vesuvio’ explosive activity, and the different effects on inhabited areas related to pyroclastic fallout and pyroclastic flow activity linked to the most renowned Plinian eruption.