Analysis of Seismic‐Driven Instability of Mt. Nuovo in the Ischia Island, Italy

We investigated the contribution of earthquake-induced surface movements to the ground displacements detected through Interferometric Synthetic Aperture Radar (InSAR) data, after the M w 3.9 Ischia earthquake on 21 August 2017. A permanent displacement approach, based on the limit equilibrium method, allowed estimation of the spatial extent of the earthquake-induced landslides and the associated probability of failure. The proposed procedure identified critical areas potentially affected by slope movements partially overlapping the coseismic ground displacement retrieved by InSAR data. Therefore, the observed ground displacement field is the combination of both fault slip and surficial sliding caused by the seismic shaking. These findings highlight the need to perform preliminary calculations to account for the non-tectonic contributions to ground displacements before any estimation of the earthquake source geometry and kinematics. Such information is fundamental to avoid both the incorrect definition of the source geometry and the possible overestimation of the coseismic slip over the causative fault. Moreover, knowledge of the areas potentially affected by slope movements could contribute to better management of a seismic emergency, especially in areas exposed to high seismic and hydrogeological risks.

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“…In particular, volcaniclastic deposits with variable thickness and strength cover the north-western flanks of Mt. Epomeo [6,29,30] (Figure 1).…”

Section: Geological Settingmentioning

confidence: 99%

The Relationship between InSAR Coseismic Deformation and Earthquake-Induced Landslides Associated with the 2017 Mw 3.9 Ischia (Italy) Earthquake

et al. 2018

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“…Among the many different potential volcanic sources, only the Somma‐Vesuvius eruptions have left geological evidence of tsunamigenesis reaching the Gulf of Naples due to dense

P D C s

entering the sea (Tinti et al, ). Other potential volcanic sources include the underwater explosions at the Campi Flegrei (Paris et al, ); lahar flows entering the sea (Paris et al, ; Tierz et al, ); potential submarine volcanic activity from other volcanoes such as Marsili, Palinuro, and Vavilov (Caratori Tontini et al, ); and the insular volcanoes (as Ischia, Stromboli, Salina, and Vulcano) (Paparo & Tinti, ; Selva et al, ).…”

Section: Discussionmentioning

confidence: 99%

“…Additional potential sources of tsunamis, which could affect the Neapolitan coast, are the debris avalanches (Tinti et al, ). The consequences of an Ischia debris avalanche were explored as single scenarios by Tinti et al () and Paparo and Tinti (). A few studies for long‐ and short‐term tsunami hazard were carried out in the region including both submarine mass failures and submarine earthquakes (Grezio et al, ; Selva et al, ).…”

Section: Introductionmentioning

confidence: 99%

Multisource Bayesian Probabilistic Tsunami Hazard Analysis for the Gulf of Naples (Italy)

et al. 2020

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A methodology for a comprehensive probabilistic tsunami hazard analysis is presented for the major sources of tsunamis (seismic events, landslides, and volcanic activity) and preliminarily applied in the Gulf of Naples (Italy). The methodology uses both a modular procedure to evaluate the tsunami hazard and a Bayesian analysis to include the historical information of the past tsunami events. In the SourceModule the submarine earthquakes and the submarine mass failures are initially identified in a gridded domain and defined by a set of parameters, producing the sea floor deformations and the corresponding initial tsunami waves. Differently volcanic tsunamis generate sea surface waves caused by pyroclastic density currents from Somma‐Vesuvius. In the PropagationModule the tsunami waves are simulated and propagated in the deep sea by a numerical model that solves the shallow water equations. In the ImpactModule the tsunami wave heights are estimated at the coast using the Green's amplification law. The selected tsunami intensity is the wave height. In the BayesianModule the probabilistic tsunami analysis computes the long‐term comprehensive Bayesian probabilistic tsunami hazard analysis. In the prior analysis the probabilities from the scenarios in which the tsunami parameter overcomes the selected threshold levels are combined with the spatial, temporal, and frequency‐size probabilities of occurrence of the tsunamigenic sources. The prior probability density functions are integrated with the likelihood derived from the historical information based on past tsunami data. The posterior probability density functions are evaluated to produce the hazard curves in selected sites of the Gulf of Naples.

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“…In literature there are several regression laws computed for the Italian territory (see Chiaruttini and Siro, 1981;Margottini et al, 1992;Decanini et al, 1995;Faccioli and Cauzzi, 2006;Faenza and Michelini, 2010;Caprio et al, 2015). If we use the relation computed recently by Paparo and Tinti (2017), one sees that in correspondence of an MCS intensity XI, the PGA is 0.51 g, much larger than the value associated with the third seismic zone. In the Fig.…”

Section: Stability Analysis Of the Hme Slopes Off Augusta Baymentioning

confidence: 95%

“…In the Fig. 6a-c, the dotted black line indicate the PGA = 0.511 g and the grey areas outline the un- Paparo and Tinti (2017). Grey areas mark the uncertainty band associated with the estimated PGA value.…”

Section: Stability Analysis Of the Hme Slopes Off Augusta Baymentioning

confidence: 99%

Earthquake-triggered landslides along the Hyblean-Malta Escarpment (off Augusta, eastern Sicily, Italy) – assessment of the related tsunamigenic potential

et al. 2017

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Abstract. Eastern Sicily is affected by earthquakes and tsunamis of local and remote origin, which is known through numerous historical chronicles. Recent studies have put emphasis on the role of submarine landslides as the direct cause of the main local tsunamis, envisaging that earthquakes (in 1693 and 1908) did produce a tsunami, but also that they triggered mass failures that were able to generate an even larger tsunami. The debate is still open, and though no general consensus has been found among scientists so far, this research had the merit to attract attention on possible generation of tsunamis by landslides off Sicily. In this paper we investigate the tsunami potential of mass failures along one sector of the Hyblean-Malta Escarpment (HME). facing Augusta. The HME is the main offshore geological structure of the region running almost parallel to the coast, off eastern Sicily. Here, bottom morphology and slope steepness favour soil failures. In our work we study slope stability under seismic load along a number of HME transects by using the Minimun Lithostatic Deviation (MLD) method, which is based on the limit-equilibrium theory. The main goal is to identify sectors of the HME that could be unstable under the effect of realistic earthquakes. We estimate the possible landslide volume and use it as input for numerical codes to simulate the landslide motion and the consequent tsunami. This is an important step for the assessment of the tsunami hazard in eastern Sicily and for local tsunami mitigation policies. It is also important in view of tsunami warning system since it can help to identify the minimum earthquake magnitude capable of triggering destructive tsunamis induced by landslides, and therefore to set up appropriate knowledge-based criteria to launch alert to the population.

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Analysis of Seismic‐Driven Instability of Mt. Nuovo in the Ischia Island, Italy

Cited by 14 publications

References 41 publications

The Relationship between InSAR Coseismic Deformation and Earthquake-Induced Landslides Associated with the 2017 Mw 3.9 Ischia (Italy) Earthquake

The Relationship between InSAR Coseismic Deformation and Earthquake-Induced Landslides Associated with the 2017 Mw 3.9 Ischia (Italy) Earthquake

Multisource Bayesian Probabilistic Tsunami Hazard Analysis for the Gulf of Naples (Italy)

Earthquake-triggered landslides along the Hyblean-Malta Escarpment (off Augusta, eastern Sicily, Italy) – assessment of the related tsunamigenic potential

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