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New evidence of syn-eruptive magma-carbonate interaction: the case study of the Pomici di Avellino eruption at Somma-Vesuvius (Italy)
No full textCalcareous 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.Published83OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Hydrothermal calcite formation in Campi Flegrei caldera, Italy: unraveling carbon sink processes in alkaline volcanic systems
No full textUnderstanding carbon dioxide emissions variability in volcanic regions is vital for detecting instabilities in the subvolcanic plumbing system, crucial for managing both volcanic and environmental risks. While changes in magmatic sources drive these variations, non-magmatic processes can complicate signal interpretation, especially in caldera environments. Here, geothermal systems can sequester CO2 within the bedrock through hydrothermal calcite precipitation, significantly impacting surface-level CO2 emissions. Unfortunately, few studies have explored this phenomenon, examining hydrothermal calcite origins and their effects on carbon balances and temporal gaseous patterns in active volcanic settings. Our study developed a specialized methodology for quantifying CO2 sequestered in hydrothermal calcites within alkaline caldera systems. We focused on analyzing hydrothermal calcite in lithics from volcanic deposits of eruptions of varying ages, Volcanic Explosivity Index (VEI), and eruptive vent locations to enhance the representativeness of the entire caldera bedrock. Unlike core samples from geothermal wells, which are infrequent and limited to specific depths, lithics can be easily collected, offering a comprehensive understanding of CO2 sequestration. Through extensive 3D textural characterization and isotopic investigations on hydrothermal calcite within lithic fragments from selected alkaline volcanic deposits in the Campi Flegrei caldera, our findings emphasized the significant influence of calcite sinks on the overall CO2 budget released by volcanoes throughout their evolution.Published16839JCR Journa
The Hydrological Impact of Historical and Modern Earthquakes in Central-Southern Italy: Data Analysis and Seismotectonic Insights
No full textAbstract
We present the results of research conducted on the hydrological effects induced by historical and modern earthquakes in the central-southern Apennines of Italy. We investigated thirty-nine seismic events of magnitude between M 4.1 and 7.1 that occurred between 1688 and 2020. We collected 526 observations of coseismic and postseismic hydrological effects such as increase or decrease in streamflow, variations in the water levels in wells, formation and/or disappearance of springs and changes in their discharge, and changes in the chemical and physical characteristics of waters. More than half of the observations were new data unpublished to date in the scientific literature. We find that the ease of finding data of interest is strongly influenced by the historical period in which the seismic event occurred. We summarize the methodology of data retrieval and its classification and present examples and maps of coseismic hydrological changes associated with individual seismic events. Most of our novel data derive from seismic postcards, macroseismic questionnaires, and hydrographic annals. However, a nonnegligible set of data comes from a careful rereading of sources—both historical and modern—that were at first considered fruitless. The majority of data concerns an excess flow in streams and springs, and physical–chemical variations such as turbidity, an increase in temperature, and gas emission. We also find that the maximum distance to which seismically induced streamflow responses have been reported can be related to the earthquake magnitude and use this distance to derive an alternative magnitude for some of the strongest earthquakes of our dataset. Finally, we show a potential application of this type of research because the distribution of coseismic hydrological changes can provide constraints in discriminating between the causative faults of strong historical seismic events for which the instrumental data are scarce or not available.In pressJCR Journa
40Ar/39Ar geochronologic and paleoenvironmental constraints to glacial termination III and MIS 7e, 7c, and 7a sea level fluctuations on the Tyrrhenian Sea coast of Italy
No full textWe provide detailed sedimentological, paleontological, and tephrochronological data on a complex sedimentary
succession cropping out in the Tyrrhenian coastal area of central Italy, which was deposited in response to sealevel
rise during MIS 7, coeval with the Latera phase of activity in the Vulsini Volcanic District. Diffuse intercalations
of primary volcanic layers erupted during this phase and their geochronologic and chemostratigraphical
characterization based on 40Ar/39Ar dating and EMP analyses, allowed for the identification of three
stacked aggradational successions separated by erosive phases and their correlation with the Oxygen isotope
record and phases in the relative sea-level curve. The ages of the tephra layers strictly frame the sedimentation in
the interval of 253–206 ka, providing independent dating to glacial Termination III and to the three sea-level
oscillations during MIS 7e, 7c, and 7a.
Moreover, micro- and macrofaunal-based analyses provide information on the paleoenvironments and bathymetry
during the highstands, which complement the geomorphological analysis reconstructing the inner
edges of the corresponding marine terraces, allowing us to assess precise maximum sea level reached during MIS
7e and MIS 7a.
The results of this multidisciplinary study enable us to establish in great detail the chronology, dynamics,
relative amplitude, and effects of the sea-level fluctuations in the Tyrrhenian Sea during the whole MIS 7,
providing independent, precise geochronological constraints for this period.Published104594OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Accelerating upper crustal deformation and seismicity of Campi Flegrei caldera (Italy), during the 2000-2023 unrest Check for updates
No full textCampi Flegrei is the largest active caldera in Europe and it is home to more than 350,000 people. Since 2005, the caldera has shown accelerating ground inflation and an intensification of seismic activity. Here we quantify the decadal accelerating trend alongside oscillations of various frequencies and explore the relationships between deformation and seismic activity over the period 2000 to November 2023. Results highlight the major changes that have occurred in the last four years analyzed and reveal a parabolic increase in vertical uplift and a super-exponential (squared-exponential) rise in the number of earthquakes and seismic energy release. Inspection of data indicate a close temporal correlation between deformation rate and seismicity, and an exponential relationship, with an exponent increasing over time, between ground deformation and cumulative number of earthquakes. These relationships are consistent with a quasi-elastic behavior and a stress memory (Kaiser) effect of the upper crust of the caldera under an increasing stress suggesting a progressive mechanical weakening. Most importantly, they provide evidence of an accelerating sensitivity of seismic activity to caldera inflation and warn of the possibility of significant seismic events in case of continuation, with the same trends and relations, of the bradyseismic crisis in the next years.Published742OSV1: Verso la previsione dei fenomeni vulcanici pericolosiJCR Journa
A geostatistical modelling of empirical amplification functions and related site proxies for shaking scenarios in central Italy
No full textThis work aims at identifying and modelling statistical dependencies between empirical amplification functions of sites in central Italy and the main geological and
geophysical characteristics of the region, within a geostatistical analysis framework. The empirical functions, named δS2S, are estimated by decomposing the re
siduals of the median predictions of a non-ergodic ground motion model of elastic acceleration response spectra developed for the reference region. To select the
model that best describes the spatial variability of the data, the performance of stationary and non-stationary spatial models is compared, the latter being able to
constrain the prediction of the empirical functions to physical quantities available in the region and descriptive of the geology, topography and geographical location
of the site. Finally, we obtain optimal models of δS2S, for each spectral ordinate, parameterised as a function of geographical coordinates and an input map of shear
wave velocity in the upper 30 m (Vs30) constructed ad hoc by combining information gathered from two high-resolution maps available for the region. The
methodology allows the development of a new practice-oriented framework for the empirical estimation of site amplification, which can be adopted for the gen
eration of shaking scenarios in the context of regional hazard and seismic risk assessment.Published108496OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Evaluating the performance of intensity prediction equations for the Italian area
No full textIn this study, we evaluate the performance of five recent Intensity Prediction Equations (IPEs) valid for Italy comparing their predictions with intensities documented at Italian localities. We build four different testing datasets using the data contained in the most recent versions of the Italian Parametric Earthquake Catalogue CPTI15 and Macroseismic Database DBMI15 and we estimate the residuals between observed and predicted intensity values for all the selected IPEs. The results are then analyzed using a measureoriented approach to score each model according to the goodness of model prediction and a diagnostic-oriented approach to investigate the trend of the residuals as a function of the different variables. The results indicate the capability of all the tested IPEs to reproduce the average decay of macroseismic intensity in Italy although with a general underestimation of high-intensity values. In addition, an in-depth investigation of the spatial and temporal patterns of the event residual term, computed using the best predictive model, is carried out. Lastly, we provide some hints for the selection of calibration datasets for the development of future intensity attenuation models.In pressJCR Journa
The last 1100 years of activity of La Fossa caldera, Vulcano Island (Italy): new insights into stratigraphy, chronology, and landscape evolution
No full textA detailed study of past eruptive activity is crucial to understanding volcanic systems and associated hazards. We present a meticulous stratigraphic analysis, a comprehensive chronological reconstruction, thorough tephra mapping, and a detailed analysis of the interplay between primary and secondary volcanic processes of the post-900 AD activity of La Fossa caldera, including the two main systems of La Fossa volcano and Vulcanello cones (Vulcano Island, Italy). Our analyses demonstrate how the recent volcanic activity of La Fossa caldera is primarily characterized by effusive and Strombolian activity and Vulcanian eruptions, combined with sporadic sub-Plinian events and both impulsive and long-lasting phreatic explosions, all of which have the capacity to severely impact the entire northern sector of Vulcano island. We document a total of 30 eruptions, 25 from the La Fossa volcano and 5 from Vulcanello cones, consisting of ash to lapilli deposits and fields of ballistic bombs and blocks. Volcanic activity alternated with significant erosional phases and volcaniclastic re-sedimentation. Large-scale secondary erosion processes occur in response to the widespread deposition of fine-grained ash blankets, both onto the active cone of La Fossa and the watersheds conveying their waters into the La Fossa caldera. The continuous increase in ground height above sea level, particularly in the western sector of the caldera depression where key infrastructure is situated, is primarily attributed to long-term alluvial processes. We demonstrate how a specific methodological approach is key to the characterization and hazard assessment of low-to-high intensity volcanic activity, where tephra is emitted over long time periods and is intercalated with phases of erosion and re-sedimentation.Open access funding provided by Istituto Nazionale di Geofisica e Vulcanologia within the CRUI-CARE Agreement.Published47OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Reawakening of Voragine, the Oldest of Etna's Summit Craters: Insights from a Recurrent Episodic Eruptive Behavior
No full textParoxysmal explosive activity at Etna volcano (Italy) has become quite frequent over the last three decades, raising concerns with the civil protection authorities due to its significant impact on the local population, infrastructures, viability and air traffic. Between 4 July and 15 August 2024, during the tourist season peak when the local population doubles, Etna volcano gave rise to a sequence of six paroxysmal explosive events from the summit crater named Voragine. This is the oldest and largest of Etna’s four summit craters and normally only produces degassing, with the previous explosive sequences occurring in December 2015 and May 2016. In this paper, we use thermal images recorded by the monitoring system maintained by the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo (INGV–OE), and an automatic procedure previously tested in order to automatically define the eruptive parameters of the six lava fountain episodes. These data allowed us to infer the eruptive processes and gain some insights on the evolution of the explosive sequences that are useful for hazard assessment. Specifically, our results lead to the hypothesis that the Voragine shallow storage has a capacity of ~12–15 Mm3, which was not completely emptied with the last two paroxysmal events. It is thus possible that one or two additional explosive paroxysmal events could occur in the future. It is noteworthy that an additional paroxysmal episode occurred at Voragine on 10 November 2024, after the submission of this paper, thus confirming our hypothesis.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BYThis research was funded by the project FIRST—ForecastIng eRuptive activity at Stromboli volcano (Delibera n. 144/2020; Scientific Responsibility: S.C.) INGV-Volcano Department, 2019. It was also supported by the Italian Research Center on High-Performance Computing Big Data and Quantum Computing (ICSC), a project funded by the European Union—NextGenerationEU—and the National Recovery and Resilience Plan (NRRP)—Mission 4 Component 2 within the activities of Spoke 3 (Astrophysics and Cosmos Observations).Published4278OSV1: Verso la previsione dei fenomeni vulcanici pericolosiJCR Journa
Preface: Recent advances in equatorial, low- and mid-latitude mesosphere, thermosphere and ionosphere studies
No full textPreface of a special issue.Published3365-3366OSA3: Climatologia e meteorologia spazialeJCR Journa