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摘要
Ischia is a volcanic island located at the margin of the Gulf of Naples in the southeastern Tyrrhenian Sea, Italy. In this article, we investigate the stability of the deep-seated block known as Mt. Nuovo in the northwestern flank of the Mt. Epomeo volcano under a combined gravitational and seismic load. Mt. Nuovo is bounded by a number of active seismic faults and is placed close to the epicentral area of the 1883 Casamicciola earthquake (I-MCS = X, M-w 5.8), that is, the largest shock occurring in the island in historical times. We explore the hypothesis that a Casamicciola-like earthquake might occur with an epicenter in the Mt. Nuovo block area. Using relationships between maximum seismic intensity and peak ground acceleration found in the literature as well as a new relationship derived specifically for this study, we apply the minimum lithostatic deviation method, which is a variant of the limit-equilibrium method, to assess the stability of the block. The main finding is that Mt. Nuovo would be mobilized if such an earthquake took place on a fault very close to the block, which would give rise to a catastrophic mass failure and to a disastrous tsunami. This calls for the need of continuous monitoring of the volcano seismicity and deformation pattern.
- 出版日期2017-4
