Abstract

It is currently impractical to measure what happens in a volcano during an explosive eruption, and up to now much of our knowledge depends on theoretical models. Here we show, by means of large-scale experiments, that the regime of explosive events can be constrained on the basis of the characteristics of magma at the point of fragmentation and conduit geometry. Our model, whose results are consistent with the literature, is a simple tool for defining the conditions at conduit exit that control the most hazardous volcanic regimes. Besides the well-known convective plume regime, which generates pyroclastic fallout, and the vertically collapsing column regime, which leads to pyroclastic flows, we introduce an additional regime of radially expanding columns, which form when the eruptive gas-particle mixture exits from the vent at overpressure with respect to atmosphere. As a consequence of the radial expansion, a dilute collapse occurs, which favors the formation of density currents resembling natural base surges. We conclude that a quantitative knowledge of magma fragmentation, i.e., particle size, fragmentation energy, and fragmentation speed, is critical for determining the eruption regime.

Autore Pugliese

• Mele Daniela , Dellino Pierfrancesco , Sulpizio Roberto

Tutti gli autori

• MELE D.;DELLINO P.;SULPIZIO R.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2010

ISSN

2156-2202

ISBN

Non Disponibile

Numero di citazioni Wos

28

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

32

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile