Antonio Costa - Profile on Academia.edu (original) (raw)

Papers by Antonio Costa

Earth, Planets and Space, 2025

Preface for EPS Special issue "Magma migration and eruptions in a volcanic group: case studies fo... more Preface for EPS Special issue "Magma migration and eruptions in a volcanic group: case studies for the 2017-2018 activity of the Kirishima Volcano Group and other global examples"

J. Volcanol. Geoterm. Res., 2025

The Ulukıs ¸la Caldera is a collapse structure within the active Hasandag Volcanic Complex (Centr... more The Ulukıs ¸la Caldera is a collapse structure within the active Hasandag Volcanic Complex (Central Anatolia), situated along the southern branch of the Tuz Gölü Fault Zone (TGFZ). This study aims to reconstruct the volcanic history of the Ulukıs ¸la Caldera by characterising its associated pyroclastic deposits using tephrostratigraphy, glass chemistry (major and trace elements), and geochronological data (40 Ar/ 39 Ar and U-(Th)-Pb). Our findings reveal that the Ulukıs ¸la Caldera has undergone at least three major explosive rhyolitic eruptions, which formed the pyroclastic deposits of the Yenipınar Eruption (~442 ka), the Belbas ¸hanı Eruption (~400 ka), and the Ulukıs ¸la Eruption (~326 ka). The Yenipınar unit was produced by an unsteady eruption column originating from paleo-Ulukıs ¸la volcanic structure, that deposited pumice fallout layers and interbedded pyroclastic density current (PDC) deposits. The Belbas ¸hanı Eruption began with a Plinian column that deposited the Belbas ¸hanı Pumice fallout. This phase was followed by the emplacement of thick PDC deposits and co-ignimbrite lithic lag breccias during the collapse, which ultimately led to the formation of the Ulukıs ¸la Caldera. The volume of the Belbas ¸hanı deposits, including the pumice fallout and the caldera-forming ignimbrite, could reach up to 10 km 3 DRE (Dense Rock Equivalent), corresponding to an eruption of magnitude ~6. The Ulukıs ¸la Pumice resulted from a post-caldera eruption, which did not generate PDCs. The Ulukıs ¸la Caldera exhibits an elongated morphology, which is strongly influenced by the NW-SE alignment of the TGFZ. Based on this morphology and the regional tectonic setting, we conclude that the Ulukıs ¸la Caldera is a strike-slip/graben caldera. Reconstructing the volcanic history of this newly identified caldera is essential for enhancing our understanding of the Hasandag Volcanic Complex. Our findings offer valuable context for future eruptive behaviour, improving the hazards assessment for potential caldera collapses, and contribute to mitigating associated risks.

Geothermics, 2025

Equilibrium in the H 2 O-H 2-CO 2-CO-CH 4 gas system has been extensively applied to fumarole dat... more Equilibrium in the H 2 O-H 2-CO 2-CO-CH 4 gas system has been extensively applied to fumarole data for geothermal exploration and volcano monitoring. However, little is known about its application to two-phase (vapor and liquid) geothermal well fluids, which can show an excess of enthalpy. Here, we applied the H 2 O-H 2-CO 2-CO-CH 4 gas indicators to two-phase geothermal well discharges from the Krafla geothermal system, Iceland, to estimate aquifer temperatures and identify secondary processes during resource exploitation. Results suggest that the Krafla resource is drawn from a deep (approximately between-500 and-1,600 m a.s.l.), two-phase aquifer with temperatures ranging from 272 to 320 • C and vapor fractions between 0.26 and 0.93, explaining the excess enthalpy observed in well fluids. These estimates align with the temperatures of the main production zones of geothermal wells, whereas solute geothermometers (SiO 2 and Na/K) appear to record lower temperatures of minor, shallower, liquid aquifers. Wells with liquid-like enthalpy are sourced from the two-phase aquifer but are also influenced by water reinjection or downflows from a colder, shallower aquifer, consistent with the isothermal zone extending approximately between 400 and-900 m a.s.l. in Leirbotnar and Vesturhlíðar subfields. Water isotopes indicate the main aquifer is recharged by meteoric and reinjection fluids. Excess-enthalpy discharges show an influx of Ar-and N 2-rich vapor, with depleted 40 Ar/ 36 Ar and δ 15 N values, suggesting fractionations of atmospheric gases dissolved into the reservoir liquid. On the other hand, δ 13 C CO2 and 3 He/ 4 He values point to a mantle origin, despite the lower δ 13 C CO2 and P CO2 levels that reflect a degassed magma (i.e., a noneruptive phase). These findings underscore the usefulness of the H 2 O-H 2-CO 2-CO-CH 4 gas system and isotopic methods in tracking geothermal reservoir temperatures, their sources, and secondary processes, such as water reinjection or downflows from shallower aquifers.

Journal of Applied Volcanology, 2016

In this study, using the tephra dispersal model HAZMAP, we investigate the effect of using differ... more In this study, using the tephra dispersal model HAZMAP, we investigate the effect of using different meteorological datasets and eruption source parameters on tephra fallout hazard assessment for a sub-Plinian eruption of Vesuvius, which is considered as a reference case for hazard assessment analysis. We analyze the effect of using different meteorological data, from: i) radio-sounding carried out at the meteorological station of Brindisi (Italy) between 1962 and 1976 and between 1996 and 2012, and at Pratica di Mare (Rome, Italy) between 1995 and 2013; ii) meteorological models of the National Oceanic and Atmospheric Administration (NOAA), and of the European Centre for Medium-Range Weather Forecasts (ECMWF). Furthermore, we consider the effects of perturbing reference eruptive source parameters. In particular, we vary the total mass, the total grain-size distribution, the column height, and the effective atmospheric diffusion coefficient to evaluate how these parameters affect the hazard probability maps. Moreover, the effect of the seasonal variation of the wind field and the effect of the rain on the deposit loading are considered. Results show that the parameter that mostly affects hazard maps is, as expected, the total erupted mass; furthermore, keeping constant the erupted mass, the most important control on hazard is due to the particle terminal settling velocity distribution which is a function of the total grain-size distribution, particle density and shape. Within the considered range variations, the hazard depends less on the use of different meteorological datasets, column height and effective diffusion coefficient.

Communications earth & environment

The Campi Flegrei caldera (Italy) is among the most productive volcanoes of the Mediterranean are... more The Campi Flegrei caldera (Italy) is among the most productive volcanoes of the Mediterranean area. However, the volcanic history preceding the VEI 7 Campanian Ignimbrite eruption (~40 ka) is still poorly constrained. Here, we use a tephra dispersal model to reconstruct the eruption source parameters of the Maddaloni/X-6 eruption (~109 ka), one of the most widespread Late Pleistocene Mediterranean marker tephra from Campi Flegrei. Our results suggest that the eruption was characterized by an early Plinian phase involving ~6 cubic kilometers (within the range of 3-21 cubic kilometers) of magma, followed by a co-ignimbrite phase erupting ~148 cubic kilometers (range of 60-300 cubic kilometers). This ranks the Maddaloni/X-6 as a high-magnitude (M7.6) eruption, resulting at least as the second largest known event from Campi Flegrei. This study provides insights into the capability of the Campi Flegrei magmatic system to repeatedly generate large explosive eruptions, which has broad implications for hazard assessment in the central Mediterranean area.

R i e s g o V o l c á n i c o P r o b a b i l i s t a Es importante tener claros algunos concepto... more R i e s g o V o l c á n i c o P r o b a b i l i s t a Es importante tener claros algunos conceptos relacionados con el análisis probabilista del riesgo, para lo cual se transcriben las definiciones propuestas por las Naciones Unidas (United Nations Disaster Relief Coordinato [UNDRO], 1990; UNISDR, 2015 UNISDR, , 2017a)). Amenaza: es un proceso, fenómeno o actividad humana que puede causar la pérdida de vidas, lesiones u otros impactos en la salud, daños a la propiedad, trastornos sociales y económicos o degradación ambiental. Los peligros pueden ser de origen natural, antropogénico o socionatural. Las amenazas naturales están predominantemente asociadas con procesos y fenómenos naturales. Cada amenaza se caracteriza por su localización, intensidad o magnitud, frecuencia y probabilidad. Análisis del riesgo de desastres: es un enfoque cualitativo o cuantitativo para determinar la naturaleza y el alcance del riesgo de desastres mediante el análisis de peligros potenciales y la evaluación de las condiciones existentes de exposición y vulnerabilidad que, en conjunto, podrían dañar a las personas, las propiedades, los servicios, los medios de subsistencia y el medio ambiente del que dependen. Las evaluaciones del riesgo de desastres incluyen: la identificación de peligros, una revisión de las características técnicas de los peligros, como su ubicación, intensidad, frecuencia y probabilidad. Capacidad: comprende la combinación de todas las fortalezas, atributos y recursos disponibles dentro de una organización, comunidad o sociedad para gestionar y reducir los riesgos de desastres y fortalecer la resiliencia. La capacidad puede incluir infraestructura, instituciones, conocimientos y habilidades humanos, y atributos colectivos como las relaciones sociales, el liderazgo y la gestión. Capacidad de afrontar: se refiere a la capacidad de las personas, las organizaciones y los sistemas, utilizando las habilidades y los recursos disponibles, para manejar condiciones adversas, riesgos o desastres. La capacidad de hacer frente requiere una conciencia continua, recursos y una buena gestión, tanto en tiempos normales como durante desastres o Glosario 19 25 condiciones adversas. Las capacidades de afrontamiento contribuyen a la reducción de los riesgos de desastres. Evacuación: se refiere al traslado temporal de personas y bienes a lugares más seguros, antes, durante o después de la ocurrencia de un evento peligroso, con el fin de protegerlos (United Nations Office for Disaster Risk Reduction [UNDRR], 2017; United Nations, 2016). Exposición: comprende la ubicación de las personas, la infraestructura, la vivienda, las capacidades de producción y otros activos humanos tangibles ubicados en áreas propensas a amenazas. Índice de exposición: es una medida cuantitativa utilizada en la evaluación de riesgos para evaluar el nivel de exposición de los elementos en riesgo ante un peligro específico , como erupciones volcánicas, terremotos o inundaciones. Proporciona una representación numérica del impacto potencial de la amenaza en los elementos. Intensidad: nivel, grado, energía o grado de impacto, expresados en términos de presión dinámica, carga de ceniza, espesor de ceniza, profundidad de enterramiento. Riesgo de desastre: es la pérdida potencial de vidas, lesiones o bienes destruidos o dañados que podría ocurrirle a un sistema, sociedad o comunidad en un período de tiempo específico, determinado probabilísticamente en función de la amenaza, la exposición, la vulnerabilidad y la capacidad. Riesgo aceptable: o riesgo tolerable, es la medida en que un riesgo de desastre se considera aceptable o tolerable. Es decir, un riesgo que la sociedad o un individuo decide que se puede asumir, por diferentes factores como son las condiciones sociales, económicas, políticas, culturales, técnicas y ambientales existentes. Riesgo residual: Es el riesgo de desastres que permanece incluso cuando se implementan medidas efectivas de reducción del riesgo de desastres y para el cual se deben mantener las capacidades de respuesta y recuperación ante emergencias.

Bulletin of Volcanology, 2024

Nisyros Island (Greece) is affected by widespread gas emissions from fumarolic fields located at ... more Nisyros Island (Greece) is affected by widespread gas emissions from fumarolic fields located at the bottom of hydrothermal craters in the southern part of its caldera. This morphology and the current low gas fluxes make Nisyros an ideal site for testing the limits of physics-based gas dispersal models in confined and low-emission conditions. Here, we focused our attention on the local scale volcanic gas dispersion from the Stephanos hydrothermal crater. In April 2023, a 1-week survey was carried out to measure weather data, CO 2 and H 2 S gas fluxes, air concentrations from portable gas stations, and chemical composition of fumarolic gases and to acquire thermal images of the crater floor. These data were used as inputs and boundary conditions for numerical simulations using a DISGAS-2.6.0 model in order to quantify the present-day volcanic degassing and its associated uncertainties, accounting for the meteorological variability. Model results are provided in terms of H 2 S probabilistic exceedance and persistence maps, showing gas concentrations within the crater that fall below the thresholds indicated for the occurrence of serious respiratory problems. Since DISGAS-2.6.0 does not account for chemical reactions, this study represents a good opportunity to discuss the methodological limits of simulating the dispersion of H 2 S which is challenging due to its rapid degradation and dilution in the atmosphere. In this regard, we also provided an empirical law of the H 2 S depletion in low-emission conditions that takes into account the uncertainties related to the field measurements.

Bull. Volc., 2024

Calcareous lithics are commonly found within the products of some explosive eruptions of Somma-Ve... more Calcareous lithics are commonly found within the products of some explosive eruptions of Somma-Vesuvius. The pumice fragments from the final phase of the Plinian fallout event of the Pomici di Avellino eruption contain abundant calcareous xenoliths. Previous work on that eruption, including numerical simulations, suggested that the release of CO 2 from the entrapment of carbonates may have prolonged the magmatic phase of the eruption by maintaining sufficient driving pressure in the feeding dike. The texture and thermo-metamorphic reactions of carbonate xenolith-bearing pumice fragments of the Pomici di Avellino eruption are analyzed through petrography, scanning electron microscope images, energy dispersive spectrometer analyses, and micro-computed X-ray tomography to deduce the behavior of short-term carbonate-magma interaction and its contribution to the eruption dynamics. Results show that calcareous xenoliths experienced short-term magma-carbonate interaction, which took place in three steps: (i) entrainment, i.e., the mechanical process of carbonate xenoliths entrapment into a magma; (ii) decarbonation, related to high-temperature decomposition reaction of the xenoliths; and (iii) digestion or dissolution of the incorporated calcareous xenoliths into the melt with diffusion of Ca and Mg. The CO 2 released during the syn-eruptive decarbonation process thus provided extra volatiles to the rising magma, which may have maintained magma buoyancy longer than expected if only magmatic volatiles were involved in the eruption.

Bulletin of Volcanology, 2024

A new method for assessing volumes of tephra deposits based on only two thickness data is present... more A new method for assessing volumes of tephra deposits based on only two thickness data is presented. It is based on the assumptions of elliptical shape for isopachs, a statistical characterization of their eccentricity, and an empirical relationship between their deposit thinning length scale and volumes. The method can be applied if the pair of thickness data are sufficiently distant from the volcano source, with a minimum distance ratio larger than 2. The method was tested against about 40 published volumes, from both equatorial belt and mid-latitude volcanoes. The results are statistically consistent with the published results, demonstrating the usefulness of the method. When applied in forward, the model allowed us to calculate the volume for some important tephra layers in the Mediterranean tephrostratigraphy, providing, for the first time, an assessment of the size of these eruptions or layers.

Bulletin of Volcanology, 2024

Hasandağ volcano (Central Anatolia, Turkey) has recently underwent an increase in local seismicit... more Hasandağ volcano (Central Anatolia, Turkey) has recently underwent an increase in local seismicity and fumarolic activity since 2013. In the past, this volcano has produced multiple large explosive eruptions during the last million years. The Belbaşhanı Pumice is the product of a sub-Plinian to Plinian eruption dated at ~ 417 ± 20.5 ka (40 Ar/ 39 Ar). Here, we present a complete volcanological study including stratigraphy, glass chemistry, pumice morphology, geochronology, and eruption source parameters with the associated uncertainties, to characterize the Belbaşhanı Pumice eruption. The eruption involved a column of 18-29 km in height, with the main dispersal axis towards the northeast. A pumice layer up to ~ 17-m-thick accumulated in proximal deposits along the Belbaşhanı path, and up to 2-m-thick in medial-distal areas (~ 18 km northeast from the vent). The high and tubular vesicularity of the pumice clasts indicates that the Belbaşhanı eruption was predominantly magmatic. The bulk volume of the Belbaşhanı Pumice fallout deposit has been estimated as 0.5 and 8 km 3 (with ~ 2 km 3 being the mean value), which corresponds to Volcanic Explosivity Index (VEI) of at least 4 and up to 6. Both isopach and isopleth maps indicate that the volcanic vent may have been located at the intersection of the Tuz Gölü fault and Ulukışla caldera, within the Hasandağ volcanic complex. The glass composition of Belbaşhanı Pumice confirms that the eruption belongs to the Hasandağ magmatic system. The reconstruction of the Belbaşhanı Pumice eruption represents an essential baseline in providing volcanological constraints for further investigations of tephra fallout hazard assessment in Central Anatolia, especially considering that a new Plinian eruption cannot be ruled out at Hasandağ volcano in the future. The chemical and geochronological datasets presented here could aid in refining tephrochronological correlations, with the goal of synchronizing paleoenvironmental and paleoclimatic records alongside archaeological sites.

Quaternary Science Reviews, 2024

The Campi Flegrei (CF) caldera, in southern Italy, is the source of some of the most powerful Lat... more The Campi Flegrei (CF) caldera, in southern Italy, is the source of some of the most powerful Late Pleistocene eruptions of the European sub-continent (e.g., Campanian Ignimbrite, Neapolitan Yellow Tuff eruptions). Although the CF caldera has been continuously and intensively investigated for decades, relatively little is known regarding its earliest volcanic activity. In this work, integrating existing and new tephrostratigraphic data, we provide a comprehensive and updated framework for the CF volcanic activity which has occurred at ~160 ka and between ~110 ka and ~90 ka. The new tephrostratigraphic, geochemical (EMPA + LA-ICP-MS), chronological (40Ar/39Ar dating) and grain-size distribution data relate to CF tephra deposits preserved in mid-proximal (Campanian Plain), distal (Tyrrhenian Sea) and ultra-distal (Lower Danube area) sedimentary archives. Our results allowed us to recognize the presence of at least 13 CF eruptions covering the investigated time frame, with 12 eruptions occurring between 110 and 90 ka. Our high-resolution stratigraphic and chronological investigation also allowed us to recognize that the Triflisco/C-22 tephra, previously considered as a single marker layer, can be actually separated into three different events, sourced from within the CF area in the short time interval of ~93- 90 ka, suggesting a more complex and intense volcanic history than previously thought. Moreover, a Bayesian age-depth model, constrained by previous and new high precision 40Ar/39Ar ages, has led to a reliable estimate of the ages of those undated CF eruptions. Overall, the updated framework on the stratigraphy, chronology, dispersion, and geochemistry of the CF tephra of ~160 ka and between 110 ka and 90 ka consolidates the notion that the Middle-Late Pleistocene activity in theCF area represents a significant stage of its volcanic evolution, characterised by intense and frequent explosive eruptions.

Solid Earth, 2024

In this study we present a novel general methodology for probabilistic volcanic hazard assessment... more In this study we present a novel general methodology for probabilistic volcanic hazard assessment (PVHA) for lahars. We apply the methodology to perform a probabilistic assessment in the Campanian Plain (southern Italy), focusing on syn-eruptive lahars from a reference size eruption from Somma–Vesuvius. We take advantage of new field data relative to volcaniclastic flow deposits in the target re- gion (Di Vito et al., 2024b) and recent improvements in modelling lahars (de’ Michieli Vitturi et al., 2024). The former allowed defining proper probability density functions for the parameters related to the flow initial conditions, and the lat- ter allowed computationally faster model runs. In this way, we are able to explore the effects of uncertainty in the initial flow conditions on the invasion of lahars in the target area by sampling coherent sets of values for the input model parameters and performing a large number of simulations. We also account for the uncertainty in the position of lahar generation by running the analysis on 11 different catchments threatening the Campanian Plain. The post-processing of the simulation outputs led to the production of hazard curves for the maximum flow thickness reached on a grid of points covering the Campanian Plain. By cutting the hazard curves at selected threshold values, we produce a portfolio of hazard maps and probability maps for the maximum flow thickness. We also produce hazard surface and probability maps for the simultaneous exceeding of pairs of thresholds in flow thick- ness and dynamic pressure. The latter hazard products represent, on one hand, a novel product in PVHA for lahars and, on the other hand, a useful means of impact assessment by assigning a probability to the occurrence of lahars that simultaneously have a relevant flow thickness and large dynamic pressure.

Solid Earth, 2024

In this paper we present a new model for the simulation of lahars based on the depth-averaged cod... more In this paper we present a new model for the simulation of lahars based on the depth-averaged code IMEX-SfloW2D with new governing and constitutive equations introduced to better describe the dynamics of lahars. A thorough sensitivity analysis is carried out to identify the critical processes (such as erosion and deposition) and parameters (both numerical and physical) controlling lahar runout using both synthetic and real case topographies. In particular, an application of the model to a syn-eruptive lahar from a reference size eruption from Somma-Vesuvius, affecting the Campanian Plain (southern Italy), described in Di Vito et al. (2024), is used in this work for the sensitivity analysis. Effects of erosion and deposition are investigated by comparing simulations with and without these processes. By comparing flow thickness and area covered by the flow and their evolution with time, we show that the modelling of both the processes is important to properly simulate the effects of the bulking and debulking as well as the associated changes in rheology. From a computational point of view, the comparisons of simulations obtained for different numerical grids (from 25 to 100 m), scheme order, and grain size discretization were useful to find a good compromise between resolution and computational speed. The companion paper by Sandri et al. (2024) shows an application of the presented model for probabilistic volcanic hazard assessment for lahars from Vesuvius deposits in the Neapolitan area.

Solid Earth, 2024

Lahars represent some of the most dangerous phenomena in volcanic areas for their destructive pow... more Lahars represent some of the most dangerous phenomena in volcanic areas for their destructive power, causing dramatic changes in the landscape with no premonitory signs and impacting the population and infrastructure. In this regard, the Campanian Plain turns out to be very prone to the development of these phenomena, since the slopes of the Somma–Vesuvius and Campi Flegrei volcanoes, along with the Apennine reliefs, are mantled by pyroclastic deposits that can be easily remobilized, especially after intense and/or pro- longed rainfall.
This study focuses on the analysis of pyroclastic fall and flow deposits and of the syn- and post-eruptive lahar deposits related to two sub-Plinian eruptions of Vesuvius in 472 CE (Pollena) and 1631. To begin with, historical and field data from the existing literature and from hundreds of outcrops were collected and organized into a database, which was integrated with several new pieces of data. In particular, strati- graphic, sedimentological (facies analysis and laboratory), and archeological analyses were carried out, in addition to rock magnetic investigations and impact parameter calculations. The new data are also referenced to the finding of ash beds in more distal areas, which were included in new isopach maps for the two sub-Plinian eruptions.
The results show that for both eruptions the distribution of the primary deposits is wider than previously known. A con-
sequence of these results is that a wider areal impact should be expected in terms of civil protection, as the sub-Plinian scenario is the reference one for a future large eruption of Vesuvius. Such a distribution of the pyroclastic deposits directly affects the one of the lahar deposits, also because a significant remobilization took place during and after the studied eruptions, which involved distal phreatomagmatic ash. From these integrated analyses, it was possible to constrain the timing of the deposition and the kind of deposits remobilized (pyroclastic fall vs. flow), and it was possible to calculate the velocities and dynamic pressures of the lahars and ultimately infer the lahar transport and emplacement mechanisms.
The multidisciplinary approach adopted in this work shows how it is crucial to assess the impact of lahars in densely populated areas even at distances of several to tens of kilometers from active volcanoes. This especially applies to large parts of the densely populated areas around Somma– Vesuvius up to the nearby Apennine valleys.

J. Volcanol. Geotherm. Res., 2024

The Krafla geothermal system is located within a volcanic center that periodically erupts basalti... more The Krafla geothermal system is located within a volcanic center that periodically erupts basaltic lavas, and has recently attracted an economic interest due to supercritical fluids forming near a shallow magma intrusion (~ 2 km depth). Here, we discuss new soil CO 2 flux and stable isotope data of the CO 2 efflux (δ 13 C) and hydrothermal calcites (δ 13 C, δ 18 O) of drill cuttings to estimate both the current magmatic outgassing from soils and the thermal flows in the geothermal system. Soil CO 2 emission is controlled by tectonics, following the NNE-SSW fissure swarm direction and a WSW-ENE trend, and accounts for ~62.5 t d − 1. While the δ 18 O of the H 2 O in equilibrium with deep calcites is predominantly meteoric, both the δ 13 C of the soil CO 2 efflux and of the fluids from which calcite precipitated have a clear magmatic origin, overlapping the δ 13 C estimated for the Icelandic mantle (− 2.5 ± 1.1 ‰). Estimates based on the soil CO 2 emission from the southern part of the system show that these fluxes might be sustained by the ascent and depressurization of supercritical fluids with a thermal energy of ~800 MW. Such significant amount of energy might reach 1.5 GW if supercritical conditions extended below the whole investigated area. Finally, we report an increase in the soil CO 2 emission of about 3 times with respect to 14 years ago, likely due to recent changes in the fluid extracted for power production or magmatic activity. Pairing the soil CO 2 emission with stable isotopes of the efflux and calcite samples has important implications for both volcano monitoring and geothermal exploration, as it can help us to track magmatic fluid upflows and the associated thermal energy.

Journal of Volcanology and Geothermal Research, 2024

PROMETHEUS is a statistical tool that allows creating maps showing the probability of finding tep... more PROMETHEUS is a statistical tool that allows creating maps showing the probability of finding tephra deposits of different grain sizes, originating from eruptions of a specific volcanic source, at any location around the vent. It couples wind profiles at different heights in the Mediterranean area with terminal velocity of volcanic particles. The input parameters include the height of the eruption column (which characterizes the intensity of the eruption), wind statistics (directions and intensities), and tephra deposits of a selected grain size. In particular, we used the parameterizations provided by Costa et al. (2016) and performed simulations using the HAZMAP tephra dispersal model to determine the maximum reachable distances that tephra can cover under weak, medium, and strong wind conditions (e.g. 7, 30, and 70 m/s velocities at the tropopause) and with column heights of 10, 20, and 30 km, depositing of at least the loading corresponding to 0.1 mm (corresponding to cryptotephra). Three alternative configurations of the model are validated analyzing first the eruptive source of Somma Vesuvius, with the related explosive eruptions from 22 ka Pomici di Base to the 1944 eruption. A further validation is made by comparing the probabilistic maps with the tephrostratigraphy of known marine and terrestrial cores using standard test of proportions (binomial distributions) and the binary logistic regression model, statistically quantifying the effectiveness of the model against the tephrostratigraphy recorded within this time frame. Based on this validation, a preferred configuration of PROMETHEUS is selected. PROMETHEUS probability maps will guide the selection of sampling sites for specific tephra deposits and could also support the study of the completeness of overall eruption catalogs over time.

Journal of Volcanology and Geothermal Research, 2024

Risk mitigation in long-dormant volcanic provinces is a challenge due to the absence of collectiv... more Risk mitigation in long-dormant volcanic provinces is a challenge due to the absence of collective memory of past disasters as well as the scarcity, and subtlety, of unrest signals that can be monitored. In this study, the impact of a potential limnic eruption is assessed at the 92-m-deep lake Pavin (French Massif Central). The lake is hosted in a maar crater formed during the last eruptive event in metropolitan France (~7 ka) and contains dissolved CO 2 in the deepest water layer, below 60 m. Carbon dioxide (CO 2) emissions measured at the lake surface (0.44 km 2) reach up to 10.1 tons/day during the winter. Beyond this (limited) continuous degassing of the lake, the current CO 2 budget in the monimolimnion layer (at a depth of 60 m to 92 m) was estimated at 1750 tons, of which about 450 tons are available for release in case of overturn of the lake. Scenarios for CO 2 dispersion in the lower atmosphere were simulated with the DISGAS and TWODEE-2 models by varying (i) meteorological conditions, (ii) the amount of CO 2 released, (iii) and the mechanisms of degassing during a potential limnic eruption. The simulations allowed identification and delimitation of areas potentially impacted by hazardous CO 2 levels in the air down-valley from the lake and directly around the lake. The spatio-temporal evolution of the potential CO 2 cloud raises issues regarding the impacts of such a hypothetical event in the close vicinity of the lake and, given the area is populated and highly visited, needs to be considered in future risk mitigation strategies.

COMMUNICATIONS EARTH & ENVIRONMENT, 2024

The Millennium Eruption of Paektu volcano, on the border of China and North Korea, gen- erated te... more The Millennium Eruption of Paektu volcano, on the border of China and North Korea, gen- erated tephra deposits that extend >1000 km from the vent, making it one of the largest eruptions in historical times. Based on observed thicknesses and compositions of the deposits, the widespread tephra dispersal is attributed to two eruption phases fuelled by chemically distinct magmas that produced both pyroclastic flows and fallout deposits. We used an ensemble-based method with a dual step inversion, in combination with the FALL3D atmospheric tephra transport model, to constrain these two different phases. The volume of the two distinct phases has been calculated. The results indicate that about 3-16 km3 (with a best estimate of 7.2 km3) and 4-20 km3 (with a best estimate of 9.3 km3) of magma were erupted during the comendite and trachyte phases of the eruption, respectively. Eruption rates of up to 4 × 10^8 kg/s generated plumes that extended 30-40 km up into the strato- sphere during each phase.

Geological Society of America Special Paper 396, 2005

Risks and damages related to effusive eruptions (e.g., the most recent Etna erup- tions) require ... more Risks and damages related to effusive eruptions (e.g., the most recent Etna erup- tions) require satisfactory models to reliably forecast lava flow paths. An overview of the principal approaches used to forecast lava flow invasion is presented: from the simple probabilistic methods to the more complex computational fluid dynamics (CFD) models. Lava flow simulations can be used for planning the evacuation or organizing countermeasures for risk mitigation during an effusive eruption. In this case, a deter- ministic approach can be very useful to forecast lava flow paths, flow front velocity, and possibly to simulate the effects of the human intervention such as the effects of lava diversion, the presence of natural or artificial barriers, etc. On the other hand, simple probabilistic models (PM) based on the “maximum slope” are able to account only for the topographic effects and, although less accurate, they can provide useful information in a very short time. These simple models also can be used in the production of hazard maps, where lava invasion probability of a given site is indicated. Typically, these maps account for different probabilities of vents opening in different areas.

Earth, Planets and Space, 2025

J. Volcanol. Geoterm. Res., 2025

Geothermics, 2025

Journal of Applied Volcanology, 2016

Communications earth & environment

Bulletin of Volcanology, 2024

Bull. Volc., 2024

Bulletin of Volcanology, 2024

Quaternary Science Reviews, 2024

Solid Earth, 2024

J. Volcanol. Geotherm. Res., 2024

Journal of Volcanology and Geothermal Research, 2024

COMMUNICATIONS EARTH & ENVIRONMENT, 2024

Geological Society of America Special Paper 396, 2005

IAEA SAFETY REPORTS SERIES No. 116, 2025

SSG‑18 describes all flooding hazards for nuclear installations. Since tsunamis and seiches can b... more SSG‑18 describes all flooding hazards for nuclear installations. Since tsunamis and seiches can be major flooding hazards for nuclear sites located on the coast, this Safety Report supports the specific areas of SSG‑18 relating to these and provides detailed methodologies and case studies that can be used by Member States for the evaluation of tsunami and seiche hazards.
Since the Great East Japan earthquake and tsunami of 11 March 2011, the importance of protecting nuclear facilities against coastal flooding and, in particular, tsunamis has received renewed attention. This event highlighted the need for deeper consideration of tsunami hazards in the design and safety assessment of nuclear installations, especially in terms of providing some defence in depth measures in such conditions.
In support of SSG‑18, this Safety Report details state of the art methodologies and provides recent case studies that may be used for the evaluation of tsunami and seiche hazards.

Natural Hazard Uncertainty Assessment: Modeling and Decision Support, Geophysical Monograph 223, 2016

Pyroclastic density currents (PDCs) are extremely dangerous phenomena so their modeling is essent... more Pyroclastic density currents (PDCs) are extremely dangerous phenomena so their modeling is essential for hazard and risk purposes. However, PDCs are governed by very complex processes, making their deterministic prediction impossible. Probabilistic approaches are in a pioneering phase and feature large (and still unknown) uncertainties, from the natural variability of PDCs (aleatory uncertainty) to the main sources of epistemic uncertainty (input, parametric, theoretical and structural). In this chapter, we quantify these uncertainties by using the Energy Cone Model (ECM) in a Monte Carlo scheme applied to Mount Vesuvius. According to our results, theoretical uncertainty has the largest impact, 5 to 100 times bigger than input uncertainty, which seems to play a minor role. We find that conditional probabilities of PDC arrival (given an eruption of a specific size)
show spatial distributions related to the surrounding topography. In particular, for medium and large eruptions, the conditional probability of PDCs traveling beyond Mount Somma is 1%–15% and 50%–60%, while they
reach the Napoli airport in about 0%–1% and 0%–15% of the simulations, respectively. Small‐eruption PDCs remain restricted to the south flank and summit area. These results may guide future research devoted to reduce
epistemic uncertainties and improve volcanic hazard analyses associated with PDCs.

Global Volcanic Hazards and Risk , 2015

Executive summary All explosive volcanic eruptions generate volcanic ash, fragments of rock that ... more Executive summary All explosive volcanic eruptions generate volcanic ash, fragments of rock that are produced when magma or vent material is explosively disintegrated. Volcanic ash is then convected upwards within the eruption column and carried downwind, falling out of suspension and potentially affecting communities across hundreds, or even thousands, of square kilometres. Ash is the most frequent, and often widespread, volcanic hazard and is produced by all explosive volcanic eruptions. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to potentially substantial societal impacts and costs, even at thicknesses of only a few millimetres. Communities exposed to any magnitude of ash fall commonly report anxiety about the health impacts of inhaling or ingesting ash (as well as impacts to animals and property damage), which may lead to temporary socioeconomic disruption (e.g. evacuation, school and business closures, cancellations). The impacts of any ash fall can therefore be experienced across large areas and can also be long-lived, both because eruptions can last weeks, months or even years and because ash may be remobilised and re-deposited by wind, traffic or human activities. Given the potentially large geographic dispersal of volcanic ash, and the substantial impacts that even thin (a few mm in thickness) deposits can have for society, this chapter elaborates upon the ash component of the overviews provided in Chapters 1 and 2. We focus on the hazard and associated impacts of ash falls; however, the areas affected by volcanic ash are potentially much larger than those affected by ash falling to the ground, as fine particles can remain aloft for extended periods of time. For example, large portions of European airspace were closed for up to five weeks during the eruption of Eyjafjallajökull, Iceland, in 2010 because of airborne ash (with negligible associated ash falls outside of Iceland). The distance and area over which volcanic ash is dispersed is strongly controlled by wind conditions with distance and altitude from the vent, but also by the size, shape and density of the ash particles, and the style and magnitude of the eruption. These factors mean that ash falls are typically deposited in the direction of prevailing winds during the eruption and thin with distance. Forecasting ash dispersion and the deposition 'footprint' is typically achieved through numerical simulation. https://www.cambridge.org/core/terms. https://doi.

STRESS FIELD CONTROL OF ERUPTION DYNAMICS, 2017

Conferenza GARR 2023 - Saperi interconnessi - Selected Papers, 2023

The project Digital Twin for GEOphysical extremes-(DT-GEO) aims to use Digital Twin Components to... more The project Digital Twin for GEOphysical extremes-(DT-GEO) aims to use Digital Twin Components to create replicas of physical systems, serving as a virtual laboratory to study natural extreme events. The rationale is the intrinsic risks of potentially catastrophic events to anthropic activities, infrastructures, and cultural heritage. In the framework of the project, this paper describes, how the DTC workflow architecture is designed, focusing on flexibility, scalability, and maintainability, and how it is further developed. To demonstrate how ICT efforts can expand horizons in Geosciences, an application to volcanic hazard is presented taking as a case study the 2019 volcanic eruption of Raikoke (Kuril Islands).