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Review of early ground deformation observations by electronic distance measurements (EDM) on active Sicilian volcanoes: valuable data and information for long-term analyses
No full textElectronic distance measurements (EDM) represent one of the first methods to detect ground deformation on volcanoes. Used since 1964, they enable acquiring precise distance measurements, whose time repetition may highlight changes related to volcanic activity. This technique was widely used on volcanoes from the 1970s to the early 2000s and has been used many times to model position, geometry, and volumes of magmatic and hydrothermal sources. This paper reports the EDM experiences, results and data acquired on Sicilian volcanoes (Etna, Vulcano, Stromboli and Pantelleria) from the early 1970s, which have played a major role in the birth of the volcano-geodesy for volcanic process knowledge, making the Sicilian volcanoes among those with the longest geodetic record in the world.PublishedJCR Journa
Experimental vs. Natural Mineral Precipitation in Modern Microbialites: The Case Study of the Alkaline Bagno Dell’acqua Lake (Pantelleria Island, Italy)
No full textPublishedJCR Journa
Tracking transient changes in the plumbing system at Campi Flegrei Caldera
No full textIncrease in seismicity, gas emission and ground uplift are symptoms of unrest in Quaternary calderas. Since the
raising of the alert level in 2012, their continuous increase in the Campi Flegrei caldera is generating growing
concerns for such a densely populated area. Until now, we never detected the injection of fresh magma in the
shallow system, leaving uncertainties on the proximity of an eruption. Here, we show evidence for episodic refills
of magma and magmatic fluids in shallow and deep reservoirs beneath the resurging area, revealed by a new
fully non-linear 4D (in space and time) seismic tomography. Transient signatures in tomograms depict the ascent
of magma batches at shallow depth, which could have started in 2019, perturbing the shallow circulation of
hydrothermal fluids. The existence of a similar signature also during the 1982–84 episode, suggests that accumulation
of magma batches may be a common way of caldera to grow. Anyway, the ability to fast track changes
associated with magma ascent is crucial to forecasting and modeling how restless calderas evolve and may
become prone to erupt.Published118744JCR Journa
Scintillation Climatology from a Software-Defined Radio Receiver over Antarctica
No full textSoftware Defined Radio (SDR) lobal avigation Satellite System (SS) receivers for operational Ionospheric Scintillation Monitoring (ISM) have faced challenges and were deemed failures by many research projects. The need for a highly stable oscillator and a robust real-time signal-tracking capability have been the main challenges. The stituto a ionale di eofisica e ulcanologia () led a pro ect called Demo R PE (Demonstrator of SS Research and pplication for Polar Environment) to deploy an SDR SS Receiver at S E Antarctica station, which has been continuously operating since January 2016. The SDR receiver was designed by the Navigation Signal Analysis and Simulation (NavSAS) group in collaboration with the Joint Research Centre (JRC) of the European Commission. The system deploys the SDR in parallel to a Septentrio PolaRxS ISM receiver. The two receivers are fed by the same receiving antenna (i.e., they share the same field of view and, hence, cross the same portion of the ionosphere) such that they receive quasi identical signals except for the independent effects of their front ends. The SDR produces as output a log file, equivalent to the S record produced by PolaRxS, that contains the amplitude and phase scintillation indexes. In addition to this, the SDR system records the raw digital samples of the GNSS signal when the internal algorithm of the receiver detects scintillation presence. These data can be used to replicate the scintillation event in the laboratory and perform dedicated post-processing of the raw signal itself. The system has been in operation for over seven years now, spanning more than half a solar cycle. It has recorded several geomagnetic storm events as well as abundant data in quiet conditions. To the best of our knowledge, this is the longest dataset of this nature (co-located PolaRxS and SDR receivers). We compare the performance of the two receivers by analyzing the scintillation climatology maps obtainable from both receivers' data. Here, the climatology is obtained using the well-established Ground-Based Scintillation Climatology (SC) technique from the data provided by the two different receivers. The study shows that the SDR climatology maps under disturbed geomagnetic conditions are equivalent to those obtained from the PolaRxS receiver. nder quiet conditions, the SDR shows more scintillation events than the PolaRxS. Carefully inspecting the differences in the scintillation occurrence between the two receivers, they seem not to happen randomly but mainly concentrated along the expected (climatological) position of the auroral oval. This means that the SDR application for space weather monitoring could be possible and that the SDR could be utilizable as an informative tool by the ionospheric scintillation community.PublishedJCR Journa
Macroseismic data in Italy. Early questionnaires and postcards: a brief history and commentary (19th and 20th centuries)
No full textThis paper is divided into two parts: the first presents a summary of the history of
macroseismic collection data in Italy, from an initial experience in the mid-19th century,
to the beginning of the use of macroseismic postcards and their evolution in the first
decades of the 20th century; the second part analyses a number of specific aspects of
the content of macroseismic postcards. An example of the reading difficulties that these
postcards pose is illustrated together with a brief comparison between the Mercalli and
Mercalli-Cancani-Sieberg scales, which serve to interpret macroseismic postcards. Both
the historical and analytical parts of the paper, aim to improve the comprehension of the
sources and, consequently, the knowledge on Italian seismicity.Published177-196OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Mechanical Energy Dissipation During Seismic Dynamic Weakening in Calcite-Bearing Faults
No full textEarthquakes are frictional instabilities caused by the shear stress decrease, that is, dynamic weakening, of faults with slip and slip rate. During dynamic weakening, shear stress depends on slip, slip rate, and temperature, according to constitutive laws governing the earthquake rupture process. In the laboratory, technical limitations in measuring temperature during frictional instabilities inhibit the investigation and interpretation of shear stress evolution. Here we conduct high velocity friction experiments on calcite-bearing simulated faults, both on bare-rock and on gouge samples, at 20-30 MPa normal stress, 1-6 m/s slip rate and 1-20 m total slip. Seismic slip pulses are reproduced by imposing boxcar and regularized Yoffe slip rate functions. We measured, together with shear stress, slip, and slip rate, the temperature evolution on the fault by employing an innovative two-color fiber optic pyrometer. The comparison between modeled and measured temperature reveals that for calcite-bearing faults the heat sink caused by decarbonation reaction controls the temperature evolution. In bare-rocks, energy is dissipated as frictional heat, and temperature increase is buffered by the heat sink of the calcite decarbonation reaction. In gouges, energy is dissipated as frictional heat and for plastic deformation processes, balanced by the heat sink caused by the decarbonation reaction enhanced by the mechanochemical effect. Our results suggest that in calcite-bearing rocks, a common fault zone material for earthquake sources in the continental crust at shallow depth, the type of fault materials (bare-rocks vs. gouges) controls the energy dissipation during seismic slip. Plain Language Summary During earthquakes, faults rocks lose strength, and therefore the ability to sustain shear stress as a consequence of slip, slip rate, and temperature resulting in dynamic weakening. The mathematical relationships between the decreasing strength and slip, slip rate, and temperature and the energy balance describing the partition of energy are of fundamental importance to model the propagation of an earthquake rupture. These relationships can be defined thanks to laboratory experiments that simulate seismic slip. Here, we tested calcite-bearing fault rocks simulated as bare-rock and gouges. During the experiments, temperature was monitored thanks to an innovative measuring system. Numerical models were done assuming all mechanical energy was converted into heat. By comparing all results above, we discovered that the mechanical energy in both bare-rocks and gouges is converted to heat but limited by the occurrence of endothermic decarbonation reaction. In gouges, also an energy contribution for plastic deformation processes is required. Our work implies significant changes in the commonly accepted energy budget for earthquake propagation and show the importance of slip rate and temperature in driving together the dynamic weakening during seismic slip.This study was funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no 856559). MC participated in this work as Principal Investigator of the European Research Council (ERC) project FEAR (Grant 856559) under the European Community's Horizon 2020 Framework Programme. SA, CC, and ES participated in this work in the framework of the European Research Council (ERC) project FEAR (Grant 856559) under the European Community's Horizon 2020 Framework Programme. This work was supported by Project MIUR 2020–2029 Working Earth—“Working Earth: Geosciences and understanding of the earth dynamics and natural hazards.” This work was supported by Project FSE+ 2021–2027, Contributi premiali per i ricercatori e assegnisti di ricerca per rafforzarne la condizione professionale e potenziare il sistema della ricerca del Lazio (Atto n. G05411 del 05/05/2022) attributed to SA, CC, and ES. SA acknowledges Christopher Harbord for the technical development of the gouge sample holder and the control system for the slip rate functions. Open Access Funding was provided by Istituto Nazionale di Geofisica e Vulcanologia within the CRUI–CARE Agreement. This work was supported by Spanish Research Agency through projects PID2021-122505OB-C32 and Juan de la Cierva FJCI-2017-31677, and by Comunidad de Madrid through TEFLON-CM Grant Y2018/EMT-4892. All authors acknowledge the editor Alexandre Schubnel and the reviewers Christie Rowe and Nir Badt for their comments and suggestions, which improved our manuscript. Open access publishing facilitated by Istituto Nazionale di Geofisica e Vulcanologia, as part of the Wiley - CRUI-CARE agreement.Publishede2024JB028927OST3 Vicino alla fagliaJCR Journa
Magnetic and chemical biomonitoring of particulate matter at cultural heritage sites: The Peggy Guggenheim Collection case study (Venice, Italy)
No full textCultural heritage (CH) is heavily threatened by air pollution, especially by airborne particulate matter (PM), that acts on the surfaces of fine arts, causing artistic loss. Therefore, the monitoring of air quality assumes a central role for the preventive conservation of CH.
In this study, magnetic and chemical biomonitoring of PM was applied at the Peggy Guggenheim Collection, a contemporary and modern art museum in Venice, Italy. It is located in an aquatic context, where the PM sources are considerably different, with respect to the usual vehicular-dominated urban emissions.
Lichen biomonitoring is a well-established technique for the assessment of air quality, especially where PM collecting devices cannot be operated for aesthetic and practical reasons.
Samples of the lichen species Evernia prunastri were collected from a pristine area and exposed for three months (November 2022–February 2023) at increasing distances from the Grand Canal, planning an outdoor vs. indoor sampling design, for outlining the diffusion of airborne PM inside the museum.
In combination with lichen exposure, the leaves of Pittosporum tobira hedges were sampled for determining their efficiency as bioaccumulators.
The magnetic properties of lichens showed a moderate bioaccumulation of magnetite-like particles outdoors. Conversely, the magnetic properties of the indoor samples were like those of the unexposed ones, indicating a negligible accumulation of metallic particles indoors. Pittosporum tobira leaves mostly showed diamagnetic properties, resulting an ineffective species for preventing conservation purposes. Chemical analysis did not show any significant difference between unexposed, indoor and outdoor samples. A directional gradient of bioaccumulation was not evident, thus implying that the sources of metallic PM are distant or diffused, with respect to the site.
The joint use of magnetic and chemical analyses was useful for evaluating the negligible impact of airborne particulate pollution arising from the Grand Canal towards the Halls of the Collection.This research was funded by INGV Project “Pianeta Dinamico” (Ministry of University and Research), research line 2023-2025 “CHIOMA”, Cultural Heritage Investigations and Observations: a Multidisciplinary Approach.
The Lakeshore 8604 VSM was funded by the Ministry of University and Research, project PON GRINT, code PIR01_00013.Published100455OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioN/A or not JC
Generation of deposit-derived pyroclastic density currents by repeated crater rim failures at Stromboli Volcano (Italy)
No full textL’instabilità del materiale vulcanoclastico caldo depositato durante l’attività eruttiva può condurre alla formazione di correnti piroclastiche, dette anche valanghe ardenti. Questi flussi possono spostarsi da distanze che vanno da centinaia di metri a diversi chilometri dalla sorgente, mantenendo temperature estremamente elevate, rappresentando così un rischio significativo per le aree circostanti i vulcani caratterizzati da pendii ripidi. La manifestazione di tali fenomeni è frequentemente associata al collasso del bordo del cratere, evento che può essere innescato da vari fattori quali la pressione esercitata dal magma, l’intrusione di dicchi, il rigonfiamento o, meno frequentemente, intense esplosioni. Nel presente studio, l’analisi dettagliata dei dati provenienti dalla rete di monitoraggio multiparametrico installata a Stromboli (Italia), che include informazioni riguardanti sorveglianza video, sismicità e deformazioni del suolo, integrate da dati topografici ottenuti tramite telerilevamento, ha facilitato l’identificazione dei fattori che hanno portato ai crolli del bordo del cratere avvenuti il 9 ottobre e il 4 dicembre 2022. Tali collassi hanno comportato la rimobilizzazione rispettivamente di 6.4 ± 1.0 × 103 m3 e 88.9 ± 26.7 × 103 m3 di materiale, il quale si è propagato sotto forma di correnti piroclastiche lungo il versante nord-occidentale del vulcano, raggiungendo il mare in poche decine di secondi. Questi eventi sono stati caratterizzati da una fase preparatoria caratterizzata da un aumento della pressione magmatica nelle settimane precedenti, correlato ad un incremento del tasso di deformazione. Inoltre, nelle ore precedenti il collasso, si è registrata una intensificazione del degassamento esplosivo, evidenziata da frequenti esplosioni di piccola entità accompagnate da un incremento del tremore sismico. Tali eventi sono stati interpretati come un iniziale aumento della vescicolarità del magma, seguito dal rilascio di gas. Il processo di degassamento ha quindi portato ad un addensamento del magma, con conseguente aumento della pressione sulle pareti del condotto magmatico. Questa fase ha coinciso con il crollo del bordo craterico, seguito o accompagnato da fasi di tracimazione lavica. Un meccanismo simile a quello proposto potrebbe fornire indicazioni utili per la comprensione di fenomeni analoghi osservati in altri vulcani. L’analisi condotta in questo studio sottolinea l’importanza di un approccio multiparametrico e a piattaforma multipla per una migliore comprensione di fenomeni così complessi. Integrando diverse tipologie di dati, tra cui informazioni sismiche, di deformazione del suolo e di telerilevamento, è possibile identificare i fenomeni associati alle diverse fasi che portano al collasso del bordo del cratere e al conseguente sviluppo di correnti piroclastiche.The gravitational instability of hot material deposited during eruptive activity can lead to the formation of glowing avalanches, commonly known as deposit-derived pyroclastic density currents (PDCs). These currents can travel hundreds of metres to several kilometres from the source at exceptionally high temperatures, posing a catastrophic hazard to areas surrounding steep-slope volcanoes. The occurrence of deposit-derived PDCs is often associated with crater rim failure, which can be triggered by various factors such as magma thrust from dike injection, magma fingering, bulging or less commonly, powerful explosions. Here, the in-depth study of data from the multi-parametric monitoring network operating on Stromboli (Italy), including video surveillance, seismicity and ground deformation data, complemented by remote topographic sensing data, has facilitated the understanding of the events leading to the crater rim collapse on 9 October and 4 December 2022. The failures resulted in the remobilisation of 6.4 ± 1.0 × 103 m3 and 88.9 ± 26.7 × 103 m3 of material for the 9 October and the 4 December 2022, respectively, which propagated as PDCs along the NW side of the volcano and reached the sea in a few tens of seconds. These events were characterised by a preparatory phase marked by an increase in magmatic pressure in the preceding weeks, which correlated with an increase in the displacement rate of the volcano’s summit. There was also an escalation in explosive degassing, evidenced by spattering accompanied by seismic tremors in the hours before the collapse.
These events have been interpreted as an initial increase in magma vesicularity, followed by the release of gas once percolation threshold was reached. The degassing process induced densification of the magma, resulting in increased thrust on the conduit walls due to increased magmastatic pressure. This phase coincided with crater rim collapse, often followed or accompanied by the onset of lava overflow phases. A mechanism similar to the one proposed may shed light on similar phenomena observed at other volcanoes. The analysis performed in this study highlights the need for a multi-parametric and multi-platform approach to fully understand such complex phenomena. By integrating different data sources, including seismic, deformation and remote sensing data, it is possible to identify the phenomena associated with the different phases leading to crater rim collapse and the subsequent development of deposit-derived PDCs.Open access funding provided by Istituto Nazionale di Geofisica e Vulcanologia within the CRUI-CARE Agreement. This research has benefited from the support from the following projects: “Convenzione B2 DPC-INGV 2022–2024, Stromboli”; INGV project Pianeta Dinamico 2023–2025-ORME; INGV project Reti Multiparametriche (Task A2); INGV Progetto Strategico Dipartimentale 2019 “UNO”; INGV Progetto Strategico Dipartimentale 2019 “FIRST”; Accordo tra Università degli Studi di Firenze e Presidenza del Consiglio dei Ministri-Dipartimento della Protezione Civile 2022–2024; Accordo tra IREA-CNR e Presidenza del Consiglio dei Ministri-Dipartimento della Protezione Civile 2022–2024 and Accordo tra IGAG-CNR e Presidenza del Consiglio dei Ministri-Dipartimento della Protezione Civile 2022–2024. Partly funded by the European Union–Next Generation EU, National Recovery and Resilience Plan Mission 4-Component 2. Project title: “Causes and consequences of deposit-derived pyroclastic density currents” (P20222BP7J). The SSAP software research and development was funded by CONAHCYT (Mexico): Proyectos Ciencia Basica: CB-2016/286764. SSAP2010 is FREEWARE software, i.e. it is distributed free of charge only at HTTPS://WWW.SSAP.EU.Published69OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Changing magma recharge/discharge dynamics during the 2020–22 lava fountaining activity at Mt. Etna revealed by tilt deformation and volcanic tremor
No full textMt. Etna exhibited 62 lava fountaining events between December 13, 2020 and February 21, 2022. We analyzed tilt deformations and volcanic tremor amplitude time series, to characterize both eruptions and the preceding preparatory phases in terms of magnitude and speed of development of the volcanic phenomena, as well as to reconstruct the processes that took place inside the plumbing system and drove this intense period of activity. Based on deflation amplitudes associated with lava fountains and according with other retrieved parameters (i.e., magnitude of inflations, inflation and deflation velocities and volcanic tremor amplitudes), three periods have been distinguished. Period I displays higher values of all the aforementioned parameters, interpreted as conspicuous volumes of volatile-rich magma transferred towards the surface. Period II shows lower values evidencing lack of important new injections of magma from depth, whereas period III reveals a general increasing trend possibly related to gas flushing from magma residing in deeper portions of the plumbing system. Detailed elaborations of tilt signals allowed the identification of short-lived inflations accompanying the early stages of lava fountains during period II. Our results reveal significant correlations between amplitude and velocity of tilt and volcanic tremor signals associated with lava fountains and evidence the crucial role of gas in the inflation-deflation cycles.Published108074JCR Journa
Marl Mining Activity and Negative Repercussions for Two Hillside Villages (Northern Italy)
No full textConiolo and Brusaschetto, are two small towns located in the Monferrato area of the Alessandria Province, northern Italy. These communities have similar histories related to develop ment and subsequent abandonment of marl quarry activity that began more than a century ago and continued until recently. Quarrying occurred until soil conditions, water infiltration, and excessive depth made cost of extracting and7 lifting material prohibitive. Quarries consisted of tunnels located directly beneath the towns at about 150 m below ground surface. Collapse of the tunnels led to surface subsidence and destruction of overlying homes and much of the municipal infrastructure. In the early Twentieth Century, regulations pertaining to mine and quarry safety were typically deficient, entirely absent, or not followed. Extractive activities of non-energy mineral resources from quarries and mines were and continue to be widespread in Italy, which currently ranks fifth among what are
now countries of the European Union (EU). Mining sites are present in all regions of Italy, particu larly in the northern part of the country and along coasts, often in areas of geohydrogeological risk.
Consequences of anthropogenic pressures that alter the natural environment, such as the physical size of aquifer drawdowns, are linked to issues for a number of extractive sites across the country. This report analyzes historical and technical documents, conducts a geomorphological analysis of hilly slopes surrounding these communities, and examines urban planning and geophysical surveys to determine the impact of subsurface quarrying activities on the overlying ground surface. The study highlights significant problems that are applicable to other localities globally. This research demonstrates: (a) the importance of geological considerations to development and abandonment of mining activity in inhabited areas; (b) the importance of establishing and following safety protocols; and (c) the manner in which economic interests can take precedence over the well-being and lives of those employed to extract resources.Published181JCR Journa