Cálculo de la probabilidad absoluta de una nueva erupción en la isla de Ischia (Italia)

Abstract

The isle of Ischia is the largest and the more populous of the Neapolitan Archipelago. It forms part of the volcanic complex of the middle-western Italian coast and its activity is related to the presence of deep fractures, associated to the aperture of the Tirreno sea, which began ten million years ago. The record of several historical eruptions reflects the possibility that in the future not so far could be produced a new volcanic event.
The calculation of this possibility represents an essential estimation to evaluate adecuately the impact that can be occasioned when the volcanic activity starts again in the isle; in fact, in a next paper, the results reached in the present study will be used to evaluate the volcanic risk in Ischia.
One of the aspects of analyses has taken into account the reconstruction of a recorder of eruptions that have been verified in the last 55.000 years, this date coincides with the emission of the Tufo Verde, one of the classification scheme proposed by Newhall and Self (1982), to each eruption has been assigned a intensity index, VEI, in order to divide all the record of classes. As follows, by applying the Poisson’s statistics, it has determined the absolute probability with which it can be produced a volcanic event of each class of VEI in a lapse of time of ten years.
The results reflect that the value of probability of eruption is not high; however, is should no be underestimated, specially with respect to two peculiar characteristics of this territory that influxes directly on the grade of volcanic risk: its high touristy flux and its insular character.