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Empirical scaling correlations between fault lengths and fault slip-rates in seismically-active extensional regions: The Calabria and Messina Strait region (southern Italy) as case study
No full textIn this study, we present scaling relationships between fault lengths, fault slip-rates and historical seismicity for an active normal fault system, seismically accommodating crustal extension within the upper plate of the Ionian subduction zone (southern Italy). This crustal extension is confirmed by historical seismicity and instrumental geodesy, with GNSS-derived values of horizonal deformation within a range of 2-3 mm/yr throughout Calabria and the Messina Strait region. We collated data for fault slip-rates, fault lengths and historical earthquakes for a given fault to explore whether fault slip-rates are correlated with fault size and their geometric moment.We present new results showing a robust correlation between fault lengths and fault slip-rates, which supports the idea of a relationship for a given fault between fault slip-rates and the geometric moment.We discuss our results in terms of how these correlations should be used if regional deformation is accommodated by localised strain on faults mostly arranged along strike rather than distributed strain on multiple faults across-strike. For instance, we compare our empirical correlation between fault lengths and fault throw-rates over the Middle-Late Pleistocene in Calabria and the Messina Strait with those from Central and Southern Apennines over the Holocene, characterized by strain distributed on multiple faults across-strike and strain localised on faults mostly arranged along-strike, respectively.Tectonic and seismic hazard implications are discussed for future investigations based on fault slip-rates, fault size and historical seismicity.PublishedVienn
Mount Etna as a terrestrial laboratory to investigate recent volcanic activity on Venus by future missions: A comparison with Idunn Mons, Venus
No full textThe recently selected missions to Venus have opened a new era for the exploration of this planet. These missions
will provide information about the chemistry of the atmosphere, the geomorphology, local-to-regional surface
composition, and the rheology of the interior. One key scientific question to be addressed by these future missions
is whether Venus remains volcanically active, and if so, how its volcanism is currently evolving. Hence, it is
fundamental to analyze appropriate terrestrial analog sites for the study of possibly active volcanism on Venus.
To this regard, we propose Mount Etna - one of the most active and monitored volcanoes on Earth - as a suitable
terrestrial laboratory for remote and in-situ investigations to be performed by future missions to Venus. Being
characterized by both effusive and explosive volcanic products, Mount Etna offers the opportunity to analyze
multiple eruptive styles, both monitoring active volcanism and identifying the possible occurrence of pyroclastic
activity on Venus. We directly compare Mount Etna with Idunn Mons, one of the most promising potentially
active volcanoes of Venus. Despite the two structures show a different topography, they also show some interesting
points of comparison, and in particular: a) comparable morpho-structural setting, since both volcanoes
interact with a rift zone, and b) morphologically similar volcanic fields around both Mount Etna and Idunn Mons.
Given its ease of access, we also propose Mount Etna as an analog site for laboratory spectroscopic studies to
identify the signatures of unaltered volcanic deposits on Venus.Published115959OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Spatio-temporal evolution of rift volcanism controlled top-down by a deepening graben
No full textVolcanism in continental rifts is generally observed to shift over time from the inside of the basin to its flanks
and vice versa, but the controls on these switches are still unclear. Here we use numerical simulations of dike
propagation to test the hypothesis that the spatio-temporal evolution of rift volcanism is controlled by the crustal
stresses produced during the development of the rift basin. We find that the progressive deepening of a rift rotates
the direction of the principal stresses under the basin, deflecting ascending dikes. This causes an early shift of
volcanism from the inside of the graben to its flanks. The intensification of this stress pattern, due to further
deepening of the basin, promotes the formation of lower crustal sill-like intrusions that can stack under the rift,
shallowing the depth at which dikes nucleate, eventually causing a late stage of in-rift axial volcanism. Given
the agreement between our model results and observations, we conclude that the temporal shifts in the location
of rift volcanism are controlled to first order by the elastic stresses developing in the crust as the rift matures.
We thereby suggest that geodynamic models should account for elasticity and the redistribution of surface loads
in order to effectively reproduce rift-related magmatism.Published118593OSV1: Verso la previsione dei fenomeni vulcanici pericolosiJCR Journa
A physically consistent AI-based SPH emulator for computational fluid dynamics
No full textThe integration of artificial intelligence (AI) into computational fluid dynamics (CFD) has significantly expanded the scope of fluid modeling, allowing enhanced analysis capabilities and improved simulation performance. While Eulerian methods already benefit extensively from AI, notably in reliable weather prediction, the application of AI to Lagrangian methods remains less consolidated. Smoothed particle hydrodynamics (SPH) is a Lagrangian mesh-less numerical method for CFD with well-established advantages for the simulation of highly dynamic free-surface flows. Here, we explore an application of AI to SPH simulations, utilizing an artificial neural network (ANN) to estimate hydrodynamic forces between particle pairs, learning from SPH-simulated results. A model of this nature, which emulates the mathematical representation of physics, is termed an emulator. We examine the physical significance of the emulator, presenting its applications in benchmark tests, assessing its faithfulness to traditional SPH simulations, and highlighting its ability to generalize and simulate test cases with varying levels of complexity beyond its training data.Published20220359JCR Journa
Imaging buried anticlines in the Po Plain, northern Italy, based on HVSR frequency and amplitude analyses
No full textKnowing the location, the extent and the characteristics of any earthquake-induced environmental phenomenon is becoming an increasingly pressing need for civil protection agencies and local administrations. In particular, earthquake-triggered landslides are known for being among the most important sources of secondary hazard, as they may cause significant losses and may delay rescue operations across large areas. The combination of the relatively frequent seismic release with a very high landslide susceptibility makes the Italian territory especially prone to the occurrence of earthquake-induced landslides. The CFTIlandslides dataset features over 1,000 landslides triggered by historical Italian earthquakes (up to 1997). The landslides effects are subdivided into classes based on location accuracy and type of movement. Knowing the distribution of the past earthquake-induced landslides provides the input information for assessing the related hazard. This dataset is addressed to a large audience of potential users, including researchers and scholars, administrators and technicians belonging to local institutions, and civil protection authorities.Published1457–1473OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Volatile organic compounds (VOCs) from diffuse degassing areas: Interstitial soil gases as message bearers from deep hydrothermal reservoirs
No full textThe chemical composition of volatile organic compounds (VOCs) in interstitial soil gases from hydrothermal areas is commonly shaped by both deep hydrothermal conditions (e.g., temperature, redox, sulfur fugacity) and shallow secondary processes occurring near the soil-atmosphere interface. Caldara di Manziana and Solfatara di Nepi, i.e., two hydrothermal systems characterized by diverse physicochemical conditions located in the Sabatini Volcanic District and Vicano-Cimino Volcanic District, respectively (Central Italy), were investigated to evaluate the capability of VOCs in soil gases to preserve information from the respective feeding deep fluid reservoirs. Hierarchical cluster analyses and robust principal component analyses allowed recognition of distinct groups of chemical parameters of soil gases collected from the two study areas. The compositional dissimilarities from the free-gas discharges were indeed reflected by the chemical features of soil gases collected from each site, despite the occurrence of shallow processes, e.g., air mixing and microbial degradation processes, affecting VOCs. Four distinct groups of VOCs were recognized suggesting similar sources and/or geochemical behaviors, as follows: (i) S-bearing compounds, whose abundance (in particular that of thiophenes) was strictly dependent on the sulfur fugacity in the feeding system; (ii) C4,5,7+ alkanes, n-hexane, cyclics and alkylated aromatics, related to relatively low-temperature conditions at the gas source; (iii) C2,3 alkanes, benzene, benzaldehyde and phenol, i.e., stable compounds and thermal degradation products; and (iv) aliphatic O-bearing compounds, largely influenced by shallow processes within the soil. However, they maintain a chemical speciation that preserves a signature derived from the supplying deep-fluids, with aldehydes and ketones becoming more enriched after intense interaction of the hypogenic fluids with shallow aquifers. Accordingly, the empirical results of this study suggest that the chemical composition of VOCs in soil gases from hydrothermal areas provides insights into both deep source conditions and fluid circulation dynamics, identifying VOCs as promising geochemical tracers for geothermal exploration.Published169047JCR Journa
Scoring and ranking probabilistic seismic hazard models: an application based on macroseismic intensity data
No full textA probabilistic seismic hazard model consists of a set of weighted models/branches that describes the center, the body and the range of seismic hazard. Owing to the intrinsic nature of this kind of analysis, the weight of each model/branch represents its scientific credibility. However, practical uses of this model may sometimes require the selection of one or a few hazard curves that are sampled from the whole model, which often consists of thousands of branches. Here we put forward an innovative procedure that facilitates the scoring, ranking and selection of the hazard curves to account for the requirements of a specific application. The approach consists of a careful quality check of the data used for scoring and the adoption of a proper scoring rule. To show the applicability of this approach, we present an example that consists of scoring and ranking a set of multiple models/branches constituting a recent seismic hazard model of Italy. To score these branches, hazard estimates produced by each of them are compared with time series of macroseismic observations available in the Italian macroseismic database for a carefully selected set of localities deemed sufficiently representative, homogeneously distributed in space and complete with respect to time and intensity levels. The proper scoring parameter used for such a comparison is the logarithmic score, which can always be applied independently of the distribution of the data.Published1401–1413OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Eugenio Scacchi e la scoperta dell’hauerite di Raddusa (notizie storiche, polemiche comprese)
No full textOne of the most interesting minerals on the Italian panorama is hauerite. This species initially found in the type-locality
of Kalinka, Slovakia (ex Hungary) was later found in Italy at Destricella, Raddusa, Sicily. This small deposit has given the
largest and qualitatively most beautiful crystals ever. Subsequently in the world hauerite was identified in several other
occurrences. Who first indirectly studied the Sicilian mineral was Eugenio Scacchi, a Neapolitan mineralogist, son of the
more famous Arcangelo, defined as the "father of Vesuvian mineralogy". The discovery of hauerite will lead to a strong
controversy between Eugenio Scacchi and Orazio Silvestri for reasons of the priority of the mineralogical discovery.Published284-292N/A or not JC
Reconciling complex stratigraphic frameworks reveals temporally and geographically variable depositional patterns of the Campanian Ignimbrite
No full textThe 39.8-ka Campanian Ignimbrite was emplaced during a large caldera-forming eruption of Campi Flegrei near Naples, Italy. The ignimbrite is found up to 80 km from the caldera, and co-ignimbrite ash-fall deposits occur 3200 km away. The proximal and distal stratigraphy of the Campanian Ignimbrite has not been definitively correlated due to the dissimilar appearance of the proximal and distal deposits, a lack of medial exposures, and the inconsistency and heterogeneity of the proximal stratigraphy. Here, we document the majorelement glass-shard chemistry, matrix componentry, and lithic componentry of the proximal and distal stratigraphic sequences of the ignimbrite to attempt to correlate the units. The results of these disparate observations taken together suggest that the established stratigraphic units cannot be directly and uniquely correlated between the proximal and distal regions and that neither the proximal nor distal stratigraphy provides a record of the entire eruptive sequence. However, the characteristics studied can be used to demarcate eruptive phases that are connected to some of the defined units in the proximal and distal stratigraphyPublished1-22OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
PSHA: Does It Deal with What It Is or What We Want It to Be?
No full textIn a recent opinion piece Albarello and Paolucci (2023; hereafter, AP23) provide their view as members of the past Seismic Group of the Commissione Grandi Rischi (CGR-SRS) in Italy, which represents the main scientific consultant for Italian Civil Protection, about the difficulty using probabilistic seismic hazard analysis (PSHA) models for building code purposes. Here, we refer to this specific kind of PSHA modeling as National Seismic Hazard Model (NSHM). We agree with AP23 that the topic is of great and general importance, and here we aim at contributing to this discussion by offering our perspective on two points that are at the heart of the matter, concluding that AP23 is misguided in how to deal with them. First, we assert that the credibility of an NSHM has to be rooted only in the use of the best available science, which includes a rigorous testing phase with observations, independent from the consequences in terms of risk. (PSHA deals with what it is.) Second, we claim that the difficulties in accepting a new NSHM with some major changes with respect to the previous model are mostly due to too rigid building code procedures that do not account for the epistemic uncertainty in the hazard estimates.Published1469–1472OST2 Deformazione e Hazard sismico e da maremotoJCR Journa