Time evolution of magma feeding system during a Plinian eruption.

Massaro S., Sulpizio R., Costa A.
  Giovedì 14/09   09:00 - 11:30   Aula A210   IV - Geofisica e fisica dell'ambiente
The geometry evolution of feeding systems due to wallrock erosion and collapse during large eruptions remains a big question mark in volcanology. Here a dynamic picture of such evolution is provided for the Pomici di Avellino (PdA) eruption (Somma-Vesuvius, Italy), an ideal case study, showing a continuous magma discharge feeding a sustained column. The PdA Plinian phases were reconstructed by coupling field data and numerical simulations. Key constraints were the lithology and amount of lithics, together with the inferred mass flow rates. The changes of the system geometry indicate a partition of driving pressure between magma ascent and changes in dyke dimensions.