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Distribution of soil gas radon concentration in north-eastern Sicily (Italy): hazard evaluation and tectonic implications
No full textRadon measurements in soil gases were carried out along the Tyrrhenian margin of north-eastern Sicily (southern Apennines
of Italy), one of the most tectonically and seismically active areas within the central Mediterranean region. The collected
data highlight an ~ NW–SE oriented zone located to the south of the Milazzo Peninsula marked by intense soil radon degassing.
Concentrations of 222Rn and 220Rn were derived to be in the range of 0.69–81.3 kBq m−
3 and 2.63–123.48 kBq m−
3,
respectively. The widespread radon release seems to be induced by the uprising of deep-originated fluids along faults and
joints, and it is favoured by the high permeability of the outcropping alluvial Quaternary sediments. Moreover, the potential
tectonic structure promoting the soil radon degassing may act as the “silent” on-land prolongation of the Vulcano-Milazzo
fault zone (VMFZ), a transtensional tectonic element located in the Gulf of Patti and belonging to the Aeolian–Tindari–
Letojanni System (ATLFS). The collected results are in accordance with previous studies showing the close relationship
between regional degassing and tectonic activity. Periodical and continuous monitoring of radon emission over the area is
considered of basic importance to better assess the radiological/health hazard for the population, which in this study was
primarily evaluated from low to moderate in terms of first-level screening, as well as in view of possible development of the
seismogenic process that can intensify the releasing of endogenous fluids.Published273JCR Journa
A kaleidoscope of colours and an unexpected journey
No full textThe paper is part of a book conceived as a "collection of stories, reflections and advice written by proficient scientists" aimed in particular at younger people and early-career researchers, with the author illustrating her most significant professional experiences.
The contribution is structured in four sections: 1) how interest in science has been developed 2) the work done and the personal scientific approach 3) perspectives on science today and tomorrow, 4) advice to much younger colleagues.Published277-2862TM. Divulgazione Scientific
Microseism and Medicane Apollo: a new approach to investigate the Mediterranean extreme weather events
No full textMicroseism is the most continuous and ubiquitous seismic signal on the Earth and is caused by the interaction between the atmosphere, the hydrosphere and the Solid Earth. In literature, there are several studies that deal with the relationship between microseism and cyclonic activity considering in particular hurricanes, tropical cyclones and typhoons. However, the relationships between microseism and the small-scale tropical cyclones that occur in the Mediterranean Sea, called Medicanes, have never been analysed. For this reason, we considered the Medicane Apollo, which developed in the Ionian Sea and impacted the eastern part of Sicily during the period 25th October to 5th November 2021 causing heavy rainfall (> 400 mm/48h), strong wind gusts (104 km/h) and violent sea waves (significant wave height > 3.5 m). Furthermore, the heavy rainfall induced by the presence of Apollo, caused damage to infrastructure and agriculture forcing the Sicilian regional government to declare a state of emergency for 32 municipalities (in the provinces of Catania, Messina, Siracusa and Ragusa) that were mostly affected by the Medicane Apollo.In this work, we analysed the microseism signal recorded by 78 seismic stations installed in South Italy, Malta and Greece coastline during the period under investigation. To obtain information about the significant wave heights, we consider the data obtained by hindcast maps and four wavemeters buoys. The spectral and amplitude analysis allowed us to obtain information about the space-time variations of the microseism amplitude and in addition, we were able both to differentiate the seismic stations that perceive Apollo (stations installed close to the Ionian Sea), the seismic stations that do not perceive the medicane (stations installed close to the Tyrrhenian sea) and the microseism bands influenced by the presence of the Medicane Apollo. Moreover, we tracked the position of the Apollo by using two different methods: i) grid search method based on the seismic amplitude decay using the 78 seismic stations first mentioned and ii) array technique by 15 seismic stations installed on Etna which may be considered an array thanks to their spatial distribution and geometry. We obtain a good match between the real positions of the Medicane Apollo derived from satellite images and the positions computed by the two analysis methods. This work shows that it is possible to extract information about the Mediterranean extreme meteo-marine events from microseism, a seismic signal that until not long ago was considered as noise, both for monitoring and research purposes.PublishedVienn
Continuous Gravity Observations at Mt. Somma-Vesuvius with a gPhoneX Gravimeter: In-Depth Instrumental Response Characterization and Tidal Model
No full textWe report on the results of about 9 months of gravimetric recordings acquired at Mt. Somma-Vesuvius (SV) volcano (Southern Italy) with the new generation relative gravimeter gPhoneX#116 (gPh#116), which is a gravimeter specifically designed for continuous gravity recording. We also present the outcomes of an intercomparison experiment of the gPhone#116 conducted at the J9 gravity observatory in Strasbourg (France). In this intercomparison, we were able to check the scale factor of the meter with a high degree of precision by means of an intercomparison with 2 superconducting gravimeters (SGs) and a FG5-type absolute ballistic gravimeter. Multiple calibration approaches allowed us to validate the manufacturer's original calibration constants to a level of 1% accuracy and 0.1% precision. Moreover, we carried out a comparative study of the noise level of the gPh#116 with respect to the SGs and other spring meters routinely used in both prospecting and time-lapse gravimetry. It turns out that gPh#116 exhibits lower levels at hourly time-scales than other compared spring gravimeters (Graviton, gPhone#054, Scintrex-CG5). It was also possible to carry out a detailed study of the instrumental drift, a crucial topic for reliable monitoring of the long-term gravity variations in active volcanic areas. In fact, a challenge in time-lapse gravimetry is the proper separation of the instrumental variations from real gravity changes eventually attributable to recharge or drainage processes of magma or fluids in the feeding systems of active volcanoes. A negative finding coming out from the intercomparison is that, even when applying the tilt correction, the gravimetric residuals obtained with the gPh#116 are an order of magnitude larger and quite inconsistent with those obtained with co-located superconducting gravimeters. We guess this problem could be overcome by installing the gravimeter on an auto-levelling platform. From the analysis of the gravity records, a reliable tidal gravity model was derived, which we believe will help to improve the accuracy of volcano monitoring, as it will allow appropriate correction of tidal effects for both relative and absolute gravity measurements acquired in the area. Two further interesting elements arose from our study: (1) a peculiar cavity effect of the SV underground laboratory that seems to influence the tilt change; (2) the small residual gravity signals are time correlated with the rainfall peaks and are compatible with gravity decreases induced by increases in soil moisture above the gravimeter.Published2625-2650OSV3: Sviluppo di nuovi sistemi osservazionali e di analisi ad alta sensibilitàJCR Journa
Editorial: Physical and statistical approaches to earthquake modeling and forecasting
No full textearthquake forecasting and testing, ETAS model, operational earthquake forecasting, statistical seismology, short-term seismic hazard assessmenPublished1268240JCR Journa
Seismic risk communication over the past 20 years: An overview of European publications
No full textThe widespread lack of awareness of seismic hazard and the inadequate preparedness to protect people and property explains the high cost of damage caused by earthquakes worldwide to date. Efficient communication is of paramount importance as part of effective risk mitigation strategies. Over the past twenty years, efforts have been pursued at the local, regional, national, and international level to disseminate information on seismic hazard to populations at risk.Focusing on Europe, we analyze the main features of seismic risk communication from 2000 to 2022, and present here an overview of the results obtained based on a scoping review of the scientific literature. Our review was conducted on publications selected from Scopus, Web of Science, and Google Scholar databases and the information was gathered on the basis of the 5 ‘Ws questions’ (Who, What, When, Where, and Why). Overall, the selected publications document the relatively limited engagement of the scientific community in this risk field compared to other natural disasters. Nevertheless, the growing trend over time of publications dealing with seismic risk communication highlights the effort to attract selected targeted audiences (particularly children), using new contents, methods of implementation, and channels such as social networks and the Internet.PublishedBerlino (Germania)OST2 Deformazione e Hazard sismico e da maremot
Magma storage and degassing beneath the youngest volcanoes of the Massif Central (France): Lessons for the monitoring of a dormant volcanic province
No full textDeveloping appropriate monitoring strategies in long-quiescent volcanic provinces is challenging
due to the rarity of recordable geochemical and geophysical signals and the lack of experienced
eruptive phenomenology in living memory. This is the case in the Massif Central (France) where
the last eruptive sequence formed the Pavin’s Group of Volcanoes, about 7 ka ago. There, current
evidence of a mantle activity reminiscence is suggested by the presence of mineral springwaters,
mofettes, and soil degassing. It appears fundamental as a prerequisite to decipher the evolution of
the gas phase in the magmatic system at the time of the eruptive activity to understand the meaning
of current local gas emissions. In this study, we develop an innovative approach coupling CO2
densimetry and geochemistry of fluid inclusions from products erupted by the Pavin’s Group of
Volcanoes. 3D imagery by Raman spectroscopy revealed that carbonate forming in fluid inclusions
may lead to underestimation of CO2 density in fluid inclusions by up to 50 % and thus to unreliable
barometric estimates. Fortunately, we found that this effect may be limited by focusing on fluid
inclusions with a small diameter (<4 m) and where no solid phase is detected on Raman spectra.
The time evolution of the eruptions of the Pavin’s Group of Volcanoes shows a progressive
decrease of the pressure of magma storage (from more than 9 kbar down to 1.5-2 kbar) in parallel to
magma differentiation (from basanites at Montcineyre to benmoreites at Pavin). The analysis of the
noble gases entrapped in fluid inclusions yielded two main conclusions: (1) the helium isotope
signature (Rc/Ra = 6.5-6.8) is in the range of values obtained in fluid inclusions from mantle
xenoliths in the Massif Central (Rc/Ra = 5.6±1.1, on average) suggesting partial melting of the
subcontinental lithospheric mantle, and (2) magma degassing (4He/40Ar* from 4.0 to 16.2) mirrors
magma differentiation and the progressive rise of the magma ponding zones of the Pavin’s Group of
Volcanoes. According to our modelling, about 80 % of the initial gas phase would be already
exsolved from these magmas, even if stored at mantle depth. Based on the results obtained from
fluid inclusions, we propose a model of the evolution of the signature of noble gases and carbon
isotopes from mantle depth to crustal levels. In this frame, gas emissions currently emitted in the
area (Rc/Ra = 6.1-6.7 and 4He/40Ar* = 1.7) point to an origin in the lithospheric mantle. This study
strongly encourages the establishment of a regular sampling of local gas emissions to detect
potential geochemical variations that may reflect a change from current steady-state conditionsPublished1216031V. Storia eruttiva2V. Struttura e sistema di alimentazione dei vulcani5V. Processi eruttivi e post-eruttiviJCR Journa
Image analysis of volcanic plumes: A simple calibration tool to correct for the effect of wind
No full textVideo cameras provide vital information on volcanic plumes from explosive eruptions, such as plume height, for monitoring and research. These images must be calibrated to get accurate quantitative data. However, the presence of wind complicates any calibration as the plume may no longer lie in the image plane, i.e. a plane perpendicular to the camera’s line-of-sight. Here, we present a simple new tool to correct for the effect of wind on the position and height of a volcanic plume as determined from imagery by rotating the image plane to be in the direction of the wind. We show the importance of accounting for the effect of wind on the maximum plume height determined from videos for two case-studies; a Vulcanian explosion from Sabancaya volcano, Peru, and a sustained plume from Mount Etna, Italy. This tool can improve the accuracy of quantitative information extracted from images of volcanic plumes, and should prove useful for both research and monitoring purposes.Published447458OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciN/A or not JC
Combining Ground Penetrating Radar and Frequency Domain Electromagnetic Surveys to Characterize the Structure of the Calderone Glacieret (Gran Sasso d’Italia, Italy)
No full textIce is a rich reservoir of past climate information, and the well-documented increasing rate
of glacier retreat represents a great loss for paleoclimate studies. In this framework, the Ice Memory
project aims to extract and analyze ice cores from glacier regions worldwide and store them in
Antarctica as a heritage record for future generations of scientists. Ice coring projects usually require
a focused geophysical investigation, often based on Ground Penetrating Radar (GPR) prospecting
to assess the most suitable drilling positions. As a novel approach in the Calderone Glacieret, we
integrated the GPR method with Frequency Domain Electromagnetic (FDEM) surveys, a technique
not commonly applied in the glacial environment. We used a separated-coils FDEM instrument
to characterize the glacieret structure. The acquired FDEM datasets were inverted and compared
to the GPR data and borehole information. The results demonstrated the capability of the FDEM
technique to define the structure of the glacieret correctly; therefore, the potential to be applied in
frozen subsoil environments. This opens new perspectives for the use of the FDEM technique to
characterize periglacial environments, such as rock glaciers, where the coarse-blocky surface hinders
data acquisition and enhances the problem of signal scattering.Published2615OSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
A Bootstrapped Modularised method of Global Sensitivity Analysis applied to Probabilistic Seismic Hazard Assessment
No full textProbabilistic Seismic Hazard Assessment (PSHA) evaluates the probability of exceedance of a given earthquake
intensity threshold like the Peak Ground Acceleration, at a target site for a given exposure time. The stochasticity
of the occurrence of seismic events is modelled by stochastic processes and the propagation of the earthquake
wave in the soil is typically evaluated by empirical relationships called Ground Motion Prediction Equations. The
large uncertainty affecting PSHA is quantified by defining alternative model settings and/or model parametri zations. In this work, we propose a novel Bootstrapped Modularised Global Sensitivity Analysis (BMGSA) method
for identifying the model parameters most important for the uncertainty in PSHA, that consists in generating
alternative artificial datasets by bootstrapping an available input-output dataset and aggregating the individual
rankings obtained with the modularized method from each of those.
The proposed method is tested on a realistic PSHA case study in Italy. The results are compared with a
standard variance-based Global Sensitivity Analysis (GSA) method of literature. The novelty and strength of the
proposed BMGSA method are both in the fact that its application only requires input-output data and not the use of a PSHA code for repeated calculations.Published1023126T. Studi di pericolosità sismica e da maremotoJCR Journa