Antonio Costa | Istituto Nazionale di Geofisica e Vulcanologia (original) (raw)
Papers by Antonio Costa
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.
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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.
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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.
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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.
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Solid Earth, 2024
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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.
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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.
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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.
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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.
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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.
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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.
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Natural Hazards and Earth System Sciences Discussions, 2014
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Chemical Geology, 2023
While long-term interactions of magma with carbonate wall-rock (a.k.a. carbonate assimilation) ar... more While long-term interactions of magma with carbonate wall-rock (a.k.a. carbonate assimilation) are well-studied, only recently some experimental studies focused on short-term interactions (seconds to minutes) at magma chamber conditions (0.5 GPa and 1200 • C). They have shown that carbonate assimilation can effectively release CO 2 and dissolve the ingested clast in syn-eruptive timescales. Carbonate wall-rock xenoliths in eruptive products can hence be seen as proof of even shallower ingestion (i.e., within the feeding dyke). To study these shallower interactions, we performed 66 experiments at atmospheric pressure (i.e., at the second endmember of the volcanic feeding system) and at 950-1230 • C with varying melt compositions and limestone compositions. Decarbonation was found to be mainly dependent on temperature and limestone composition while clast dissolution is largely dependent on magma composition, temperature, pressure and interaction time. In natural systems during magma ascent and with increasing quantities of assimilated wall-rock, the magma temperature would steadily decrease, limiting its own decarbonation and assimilation ability. But even in the 950 • C-experiments decarbonation (i.e., CO 2 release) remained a syn-eruptive process. We subsequently discussed the limits of carbonate assimilation as well as the potential effect of syn-eruptive addition of CO 2 to the magmatic mixture on magma ascent and eruption dynamics.
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Journal of Applied Volcanology, 2023
The Aso-4 explosive eruption on Kyushu, Japan, 89,500 years ago was one of the biggest eruptions ... more The Aso-4 explosive eruption on Kyushu, Japan, 89,500 years ago was one of the biggest eruptions in the last one hundred millennia, with a magnitude of approximately M8. Modern society requires the likelihood of natural events with potentially disastrous consequences to be evaluated, even if probabilities of occurrence are diminishingly small. For some situations, it is not satisfactory to assert an event scenario probability is “negligible” or can be “ignored”. Judicial hearings or litigation may require risk levels to be quantified, in which case, statements of scientific confidence could be decisive. Internation- ally, e.g., for nuclear site safety evaluations, event likelihoods on order of 10–7/year are often considered for quantitative assessment. At such hazard levels, this might include evaluating the proposition that a particular volcano can deliver
a future super-eruption, a supposition that could be attached to Aso volcano. But, simplistically taking the average recurrence interval between past caldera-forming eruptions at a given volcano is an unreliable guide to the likelihood
of a future repeat: each past event represented a unique set of tectonic and magmatic conditions within a continually evolving volcanic system. Such processes are not temporally stationary nor statistically uniform. To evaluate the probability of a new M8 event at Aso, within the next 100 years, we performed a comprehensive stochastic probability uncertainty analysis using a model implemented with advanced computational Bayes Net (BN) software. Our eruption process
model is informed by multiple strands of evidence from volcanology, petrology, geochemistry and geophysics, together with estimates of epistemic (knowledge) uncertainty, adduced from reviews of published data, modelling and from expert judgement elicitation. Several lines of evidence characterise the likely structure, magmatic composition and eruptive
state of the present-day Aso volcano, which has had numerous smaller eruptions since Aso-4. To calculate the probability of another M8 eruption of Aso, we implemented probabilistic ‘Importance Sampling’ in our model. With this approach, we find the chance of an Aso-4 scale eruption (characterised by mean volume 500 km3 DRE and approximate 90% credible interval [210 .. 1200] km3 DRE) is less than 1–in–1 billion in the next 100 years (i.e., < 10–9 probability). Based on current volcanological understanding and evidence, we believe this probability estimate is robust to within an order of magnitude.
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Geosci. Model Dev., 2023
In recent years, there has been a growing inter- est in ensemble approaches for modelling the atm... more In recent years, there has been a growing inter- est in ensemble approaches for modelling the atmospheric transport of volcanic aerosol, ash, and lapilli (tephra). The development of such techniques enables the exploration of novel methods for incorporating real observations into tephra dispersal models. However, traditional data assimilation algorithms, including ensemble Kalman filter (EnKF) meth- ods, can yield suboptimal state estimates for positive-definite variables such as those related to volcanic aerosols and tephra deposits. This study proposes two new ensemble- based data assimilation techniques for semi-positive-definite variables with highly skewed uncertainty distributions, including aerosol concentrations and tephra deposit mass load- ing: the Gaussian with non-negative constraints (GNC) and gamma inverse-gamma (GIG) methods. The proposed methods are applied to reconstruct the tephra fallout deposit resulting from the 2015 Calbuco eruption using an ensemble of 256 runs performed with the FALL3D dispersal model. An assessment of the methodologies is conducted consider- ing two independent datasets of deposit thickness measurements: an assimilation dataset and a validation dataset. Different evaluation metrics (e.g. RMSE, MBE, and SMAPE) are computed for the validation dataset, and the results are compared to two references: the ensemble prior mean and the EnKF analysis. Results show that the assimilation leads to a significant improvement over the first-guess results obtained from the simple ensemble forecast. The evidence from this study suggests that the GNC method was the most skilful approach and represents a promising alternative for assimilation of volcanic fallout data. The spatial distributions of the tephra fallout deposit thickness and volume according to the GNC analysis are in good agreement with estimations based on field measurements and isopach maps reported in previous studies. On the other hand, although it is an interesting approach, the GIG method failed to improve the EnKF analysis.
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Nat. Hazards Earth Syst. Sci., 2023
Nowadays, modeling of tephra fallout hazard is coupled with probabilistic analysis that takes int... more Nowadays, modeling of tephra fallout hazard is coupled with probabilistic analysis that takes into account the natural variability of the volcanic phenomena in terms of eruption probability, eruption sizes, vent position, and mete- orological conditions. In this framework, we present a proto- typal methodology to carry out the long-term tephra fallout hazard assessment in southern Italy from the active Neapolitan volcanoes: Somma–Vesuvius, Campi Flegrei, and Ischia.
The FALL3D model (v.8.0) has been used to run thousands of numerical simulations (1500 per eruption size class), considering the ECMWF ERA5 meteorological dataset over the last 30 years. The output in terms of tephra ground load has been processed within a new workflow for large-scale, high- resolution volcanic hazard assessment, relying on a Bayesian procedure, in order to provide the mean annual frequency with which the tephra load at the ground exceeds given criti- cal thresholds at a target site within a 50-year exposure time. Our results are expressed in terms of absolute mean hazard maps considering different levels of aggregation, from the impact of each volcanic source and eruption size class to the quantification of the total hazard. This work provides, for the first time, a multi-volcano probabilistic hazard assessment posed by tephra fallout, comparable with those used for seismic phenomena and other natural disasters. This method- ology can be applied to any other volcanic areas or over dif- ferent exposure times, allowing researchers to account for the eruptive history of the target volcanoes that, when available, could include the occurrence of less frequent large eruptions, representing critical elements for risk evaluations.
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J. Volcan. Geotherm. Res., 2023
Caldeiras da Ribeira Grande is one of the degassing areas of Fogo, a trachytic central volcano lo... more Caldeiras da Ribeira Grande is one of the degassing areas of Fogo, a trachytic central volcano located at São Miguel Island (Azores archipelago). Recently, new steam emissions, soil CO 2 and temperature anomalies developed towards the inhabited area, causing high indoor CO 2 values and affecting the vegetation and several small animals that were found dead in depressions and low-ventilated zones. During July-August 2021, a soil CO 2 flux survey was carried out on the north flank of the volcano, estimating a soil gas release of at least 40 t d − 1 (excluding the contribution of the fumaroles) over an area of ~0.27 km 2. Two populations for the CO 2 released were found, highlighting the biogenic and volcanic-hydrothermal origins. General NW-SE diffuse degassing structures (DDS) were identified, in agreement with the tectonic lineaments previously recognized in the area. In this regard, we investigated the passive gas dispersion in the atmosphere at Caldeiras da Ribeira Grande performing a model validation aimed to estimate the fumarolic gas flux at source and the potential hazard for human and animal lives posed by CO 2. Numerical simulations were carried out with the DISGAS-2.3, a 3D Eulerian advection-diffusion model, and the relative outputs processed through the VIGIL-1.3 workflow able to provide probabilistic long-term CO 2 concentration maps, considering a meteorological variability over the last 30 years (1991-2020) taken from the ECMWF ERA5 reanalysis dataset. A best-fit between observed and simulated CO 2 concentrations allowed us to estimate the total gas flux of the area (~209 t d − 1) obtained by scaling the soil CO 2 gas flux by a factor 30. Such an estimate is composed of ~174 t d − 1 as unknown fumarolic and ~ 35 td − 1 as diffuse contribution, in a good agreement with measurements. Although the present-day CO 2 concentration at 0.3 m height cannot be considered to raise serious concerns for human health, we reasonably infer that the death of small animals may be due to local conditions of CO 2 accumulation or to the presence of H 2 S. The current study highlights the relevance of coupling gas flux maps, concentration data, and gas dispersion modeling to obtain robust estimation of gas fluxes, including the fumarolic contribution, and identify zones potentially impacted by dangerous concentrations of volcanic gases, which are relevant for land-use planning and hazard assessment in case of renewed escalations of volcanic activity.
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Future Generation Computer Systems, 2023
The EU Center of Excellence for Exascale in Solid Earth (ChEESE) develops exascale transition cap... more The EU Center of Excellence for Exascale in Solid Earth (ChEESE) develops exascale transition capabilities in the domain of Solid Earth, an area of geophysics rich in computational challenges embracing different approaches to exascale (capability, capacity, and urgent computing). The first implementation phase of the project (ChEESE-1P; 2018-2022) addressed scientific and technical computational challenges in seismology, tsunami science, volcanology, and magnetohydrodynamics, in order to understand the phenomena, anticipate the impact of natural disasters, and contribute to risk management. The project initiated the optimisation of 10 community flagship codes for the upcoming exascale systems and implemented 12 Pilot Demonstrators that combine the flagship codes with dedicated workflows in order to address the underlying capability and capacity computational challenges. Pilot Demonstrators reaching more mature Technology Readiness Levels (TRLs) were further enabled in operational service environments on critical aspects of geohazards such as long-term and short-term probabilistic hazard assessment, urgent computing, and early warning and probabilistic forecasting. Partnership and service co-design with members of the project Industry and User Board (IUB) leveraged the uptake of results across multiple research institutions, academia, industry, and public governance bodies (e.g. civil protection agencies). This article summarises the implementation strategy and the results from ChEESE-1P, outlining also the underpinning concepts and the roadmap for the ongoing second project implementation phase (ChEESE-2P; 2023-2026).
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Geological Society, London, Special Publications
The interaction of magma and wall-rocks is inevitable when magma is moving through Earth's cr... more The interaction of magma and wall-rocks is inevitable when magma is moving through Earth's crust. These interactions happen on different timescales and especially the short-term interactions (seconds to days) during the final ascent of the magma can induce changes in eruption dynamics. However, information on this matter is scarce and scattered in different scientific fields. We conducted this review in order to present a full picture of the state of the art for short-timescale magma–wall-rock interactions. According to the three existing studies on short-term magma–carbonate interactions, magma viscosity is the most important controlling factor for carbonate assimilation. Lower viscosity magmas enhance CO2-bubble migration away from the reaction site, resulting in a higher carbonate assimilation rate. The released CO2 plays an important role regarding eruption dynamics since a higher CO2 release rate would result in accelerated magma ascent and may increase eruption intensity. ...
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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.
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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.
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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.
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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.
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Solid Earth, 2024
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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.
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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.
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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.
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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.
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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.
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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.
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Natural Hazards and Earth System Sciences Discussions, 2014
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Chemical Geology, 2023
While long-term interactions of magma with carbonate wall-rock (a.k.a. carbonate assimilation) ar... more While long-term interactions of magma with carbonate wall-rock (a.k.a. carbonate assimilation) are well-studied, only recently some experimental studies focused on short-term interactions (seconds to minutes) at magma chamber conditions (0.5 GPa and 1200 • C). They have shown that carbonate assimilation can effectively release CO 2 and dissolve the ingested clast in syn-eruptive timescales. Carbonate wall-rock xenoliths in eruptive products can hence be seen as proof of even shallower ingestion (i.e., within the feeding dyke). To study these shallower interactions, we performed 66 experiments at atmospheric pressure (i.e., at the second endmember of the volcanic feeding system) and at 950-1230 • C with varying melt compositions and limestone compositions. Decarbonation was found to be mainly dependent on temperature and limestone composition while clast dissolution is largely dependent on magma composition, temperature, pressure and interaction time. In natural systems during magma ascent and with increasing quantities of assimilated wall-rock, the magma temperature would steadily decrease, limiting its own decarbonation and assimilation ability. But even in the 950 • C-experiments decarbonation (i.e., CO 2 release) remained a syn-eruptive process. We subsequently discussed the limits of carbonate assimilation as well as the potential effect of syn-eruptive addition of CO 2 to the magmatic mixture on magma ascent and eruption dynamics.
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Journal of Applied Volcanology, 2023
The Aso-4 explosive eruption on Kyushu, Japan, 89,500 years ago was one of the biggest eruptions ... more The Aso-4 explosive eruption on Kyushu, Japan, 89,500 years ago was one of the biggest eruptions in the last one hundred millennia, with a magnitude of approximately M8. Modern society requires the likelihood of natural events with potentially disastrous consequences to be evaluated, even if probabilities of occurrence are diminishingly small. For some situations, it is not satisfactory to assert an event scenario probability is “negligible” or can be “ignored”. Judicial hearings or litigation may require risk levels to be quantified, in which case, statements of scientific confidence could be decisive. Internation- ally, e.g., for nuclear site safety evaluations, event likelihoods on order of 10–7/year are often considered for quantitative assessment. At such hazard levels, this might include evaluating the proposition that a particular volcano can deliver
a future super-eruption, a supposition that could be attached to Aso volcano. But, simplistically taking the average recurrence interval between past caldera-forming eruptions at a given volcano is an unreliable guide to the likelihood
of a future repeat: each past event represented a unique set of tectonic and magmatic conditions within a continually evolving volcanic system. Such processes are not temporally stationary nor statistically uniform. To evaluate the probability of a new M8 event at Aso, within the next 100 years, we performed a comprehensive stochastic probability uncertainty analysis using a model implemented with advanced computational Bayes Net (BN) software. Our eruption process
model is informed by multiple strands of evidence from volcanology, petrology, geochemistry and geophysics, together with estimates of epistemic (knowledge) uncertainty, adduced from reviews of published data, modelling and from expert judgement elicitation. Several lines of evidence characterise the likely structure, magmatic composition and eruptive
state of the present-day Aso volcano, which has had numerous smaller eruptions since Aso-4. To calculate the probability of another M8 eruption of Aso, we implemented probabilistic ‘Importance Sampling’ in our model. With this approach, we find the chance of an Aso-4 scale eruption (characterised by mean volume 500 km3 DRE and approximate 90% credible interval [210 .. 1200] km3 DRE) is less than 1–in–1 billion in the next 100 years (i.e., < 10–9 probability). Based on current volcanological understanding and evidence, we believe this probability estimate is robust to within an order of magnitude.
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Geosci. Model Dev., 2023
In recent years, there has been a growing inter- est in ensemble approaches for modelling the atm... more In recent years, there has been a growing inter- est in ensemble approaches for modelling the atmospheric transport of volcanic aerosol, ash, and lapilli (tephra). The development of such techniques enables the exploration of novel methods for incorporating real observations into tephra dispersal models. However, traditional data assimilation algorithms, including ensemble Kalman filter (EnKF) meth- ods, can yield suboptimal state estimates for positive-definite variables such as those related to volcanic aerosols and tephra deposits. This study proposes two new ensemble- based data assimilation techniques for semi-positive-definite variables with highly skewed uncertainty distributions, including aerosol concentrations and tephra deposit mass load- ing: the Gaussian with non-negative constraints (GNC) and gamma inverse-gamma (GIG) methods. The proposed methods are applied to reconstruct the tephra fallout deposit resulting from the 2015 Calbuco eruption using an ensemble of 256 runs performed with the FALL3D dispersal model. An assessment of the methodologies is conducted consider- ing two independent datasets of deposit thickness measurements: an assimilation dataset and a validation dataset. Different evaluation metrics (e.g. RMSE, MBE, and SMAPE) are computed for the validation dataset, and the results are compared to two references: the ensemble prior mean and the EnKF analysis. Results show that the assimilation leads to a significant improvement over the first-guess results obtained from the simple ensemble forecast. The evidence from this study suggests that the GNC method was the most skilful approach and represents a promising alternative for assimilation of volcanic fallout data. The spatial distributions of the tephra fallout deposit thickness and volume according to the GNC analysis are in good agreement with estimations based on field measurements and isopach maps reported in previous studies. On the other hand, although it is an interesting approach, the GIG method failed to improve the EnKF analysis.
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Nat. Hazards Earth Syst. Sci., 2023
Nowadays, modeling of tephra fallout hazard is coupled with probabilistic analysis that takes int... more Nowadays, modeling of tephra fallout hazard is coupled with probabilistic analysis that takes into account the natural variability of the volcanic phenomena in terms of eruption probability, eruption sizes, vent position, and mete- orological conditions. In this framework, we present a proto- typal methodology to carry out the long-term tephra fallout hazard assessment in southern Italy from the active Neapolitan volcanoes: Somma–Vesuvius, Campi Flegrei, and Ischia.
The FALL3D model (v.8.0) has been used to run thousands of numerical simulations (1500 per eruption size class), considering the ECMWF ERA5 meteorological dataset over the last 30 years. The output in terms of tephra ground load has been processed within a new workflow for large-scale, high- resolution volcanic hazard assessment, relying on a Bayesian procedure, in order to provide the mean annual frequency with which the tephra load at the ground exceeds given criti- cal thresholds at a target site within a 50-year exposure time. Our results are expressed in terms of absolute mean hazard maps considering different levels of aggregation, from the impact of each volcanic source and eruption size class to the quantification of the total hazard. This work provides, for the first time, a multi-volcano probabilistic hazard assessment posed by tephra fallout, comparable with those used for seismic phenomena and other natural disasters. This method- ology can be applied to any other volcanic areas or over dif- ferent exposure times, allowing researchers to account for the eruptive history of the target volcanoes that, when available, could include the occurrence of less frequent large eruptions, representing critical elements for risk evaluations.
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J. Volcan. Geotherm. Res., 2023
Caldeiras da Ribeira Grande is one of the degassing areas of Fogo, a trachytic central volcano lo... more Caldeiras da Ribeira Grande is one of the degassing areas of Fogo, a trachytic central volcano located at São Miguel Island (Azores archipelago). Recently, new steam emissions, soil CO 2 and temperature anomalies developed towards the inhabited area, causing high indoor CO 2 values and affecting the vegetation and several small animals that were found dead in depressions and low-ventilated zones. During July-August 2021, a soil CO 2 flux survey was carried out on the north flank of the volcano, estimating a soil gas release of at least 40 t d − 1 (excluding the contribution of the fumaroles) over an area of ~0.27 km 2. Two populations for the CO 2 released were found, highlighting the biogenic and volcanic-hydrothermal origins. General NW-SE diffuse degassing structures (DDS) were identified, in agreement with the tectonic lineaments previously recognized in the area. In this regard, we investigated the passive gas dispersion in the atmosphere at Caldeiras da Ribeira Grande performing a model validation aimed to estimate the fumarolic gas flux at source and the potential hazard for human and animal lives posed by CO 2. Numerical simulations were carried out with the DISGAS-2.3, a 3D Eulerian advection-diffusion model, and the relative outputs processed through the VIGIL-1.3 workflow able to provide probabilistic long-term CO 2 concentration maps, considering a meteorological variability over the last 30 years (1991-2020) taken from the ECMWF ERA5 reanalysis dataset. A best-fit between observed and simulated CO 2 concentrations allowed us to estimate the total gas flux of the area (~209 t d − 1) obtained by scaling the soil CO 2 gas flux by a factor 30. Such an estimate is composed of ~174 t d − 1 as unknown fumarolic and ~ 35 td − 1 as diffuse contribution, in a good agreement with measurements. Although the present-day CO 2 concentration at 0.3 m height cannot be considered to raise serious concerns for human health, we reasonably infer that the death of small animals may be due to local conditions of CO 2 accumulation or to the presence of H 2 S. The current study highlights the relevance of coupling gas flux maps, concentration data, and gas dispersion modeling to obtain robust estimation of gas fluxes, including the fumarolic contribution, and identify zones potentially impacted by dangerous concentrations of volcanic gases, which are relevant for land-use planning and hazard assessment in case of renewed escalations of volcanic activity.
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Future Generation Computer Systems, 2023
The EU Center of Excellence for Exascale in Solid Earth (ChEESE) develops exascale transition cap... more The EU Center of Excellence for Exascale in Solid Earth (ChEESE) develops exascale transition capabilities in the domain of Solid Earth, an area of geophysics rich in computational challenges embracing different approaches to exascale (capability, capacity, and urgent computing). The first implementation phase of the project (ChEESE-1P; 2018-2022) addressed scientific and technical computational challenges in seismology, tsunami science, volcanology, and magnetohydrodynamics, in order to understand the phenomena, anticipate the impact of natural disasters, and contribute to risk management. The project initiated the optimisation of 10 community flagship codes for the upcoming exascale systems and implemented 12 Pilot Demonstrators that combine the flagship codes with dedicated workflows in order to address the underlying capability and capacity computational challenges. Pilot Demonstrators reaching more mature Technology Readiness Levels (TRLs) were further enabled in operational service environments on critical aspects of geohazards such as long-term and short-term probabilistic hazard assessment, urgent computing, and early warning and probabilistic forecasting. Partnership and service co-design with members of the project Industry and User Board (IUB) leveraged the uptake of results across multiple research institutions, academia, industry, and public governance bodies (e.g. civil protection agencies). This article summarises the implementation strategy and the results from ChEESE-1P, outlining also the underpinning concepts and the roadmap for the ongoing second project implementation phase (ChEESE-2P; 2023-2026).
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Geological Society, London, Special Publications
The interaction of magma and wall-rocks is inevitable when magma is moving through Earth's cr... more The interaction of magma and wall-rocks is inevitable when magma is moving through Earth's crust. These interactions happen on different timescales and especially the short-term interactions (seconds to days) during the final ascent of the magma can induce changes in eruption dynamics. However, information on this matter is scarce and scattered in different scientific fields. We conducted this review in order to present a full picture of the state of the art for short-timescale magma–wall-rock interactions. According to the three existing studies on short-term magma–carbonate interactions, magma viscosity is the most important controlling factor for carbonate assimilation. Lower viscosity magmas enhance CO2-bubble migration away from the reaction site, resulting in a higher carbonate assimilation rate. The released CO2 plays an important role regarding eruption dynamics since a higher CO2 release rate would result in accelerated magma ascent and may increase eruption intensity. ...
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Global Volcanic Hazards and Risk , 2015
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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.
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STRESS FIELD CONTROL OF ERUPTION DYNAMICS, 2017
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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).
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