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PRELIMINARY PSHA APPLICATION OF AN INTENSITY PREDICTION EQUATION IN ITALY CONSIDERING POSSIBLE INFLUENCE OF SOIL CONDITIONS POSTER 123
No full textThe macroseismic intensity specifically relates to damage in a way that parameters like Peak Ground Acceleration (PGA) do not, thus providing a practical
measure to guide the priorities of Civil Protection interventions immediately following an event. In this study, we analyze the new macroseismic intensity
attenuation models proposed by Gomez-Capera et al. (2024), which are calibrated in moment magnitude (Mw) for the Italian territory, focusing on their potential
application in developing Probabilistic Seismic Hazard Assessment (PSHA) maps in terms of macroseismic intensity I. Specifically, we elected to test the Log-
Lin_10 model for macroseismic intensity due to its simpler mathematical and computational properties. A primary goal of these attenuation models is to allow
for the assessment of seismic hazard maps directly in terms of macroseismic intensity, thereby avoiding the uncertainties associated with converting various
ground shaking parameters into intensity values. In the present study, we compare the PSHA map obtained directly using the Gomez-Capera et al. (2024) model
with that derived from the Gomez-Capera et al. (2022) conversion of the PGA parameter into intensity I, and with the Italian National Seismic Hazard Map
(MPS04) in terms of macroseismic intensity (Gruppo di Lavoro MPS, 2004).PublishedCorfu Holiday Palace Hotel, Corfu, GreeceOST2 Deformazione e Hazard sismico e da maremot
High-resolution geophysical investigations in the central Apennines seismic belt (Italy): Results from the Campo Felice tectonic basin
No full textThe Campo Felice basin, in the central Apennines seismic belt (Italy), developed in the hangingwall of a 30 km-long system of NW-trending normal faults with Holocene paleoseismic activity and potential sources of M 6–7 earthquakes. We provide the first subsurface images of a key portion of the basin bounded by the Mt. Cefalone fault along two intersecting profiles trending NNE-SSW (CF-Dip, 1195 m-long) and WNW-ESE (CF-Strike, 1315-m long). We combined high-resolution depth-migrated reflection sections with P-wave velocity and electrical resistivity tomography models. CF-Dip profile displays a wedge-like syn-tectonic sedimentary sequence of alluvial and glacial deposits with Vp ∼ 2500–3000 m/s and resistivity > 500 Ωm in the hangingwall of Mt. Cefalone fault, overlying a high-Vp (>4000 m/s) limestone bedrock ∼ 300 m deep. The whole sequence displays reflectors truncated by the Mt. Cefalone fault zone and subsidiary antithetic faults. CF-Strike profile, tied to three 80–110 m-deep boreholes, shows a thick fluvio-lacustrine sequence with low-Vp (450 m). Single-station ambient noise measurements display Horizontal to Vertical Spectral Ratios with peaks at ∼1 Hz, decreasing to ∼0.8 Hz to the southeast in agreement with the bedrock deepening indicated by seismic profiling. According to our results, the Campo Felice basin is a deep asymmetric half-graben controlled by faulting whose activity likely started before the Middle Pleistocene. Our minimum displacement estimate accrued in the past 0.5 Ma by the Mt. Cefalone fault is in the range of ∼100–250 m.Published230170OST2 Deformazione e Hazard sismico e da maremotoOST3 Vicino alla fagliaOSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioJCR Journa
Localization of Deformation on Faults Driven by Fluids During the L’Aquila 2009 Earthquake
No full textCoseismic rupture and aftershock development on a fault plane are complex and heterogeneous processes. The Mw 6.1 L’Aquila 2009 normal faulting earthquake is a perfect case to explore how fault geometry and rheology influence the rupture process and aftershocks distribution. In this study, we use for the first time a dense set of earthquake data to obtain enhanced images of the causative normal fault structure to the kilometer scale. The hypocenter of the emergent onset of the mainshock took place within a low Vp/Vs volume, while the large coseismic slip occurred a few kilometers above, as the rupture propagated through a high Vp and high Vp/Vs fluid-filled rock volume. The increase of Vp/Vs in the fault hanging wall during the sequence suggests a strong dehydration in the earthquake asperity, with an upward fluid pressure migration along the fault toward the host rock volume. We propose that the localization of deformation on the fault plane is favored by high fluid pressure, while the spreading of aftershocks on a wide volume around the fault is driven by the depletion of fluids from the slipped portion of the fault plane and migration to small segments within the fault host rocks.Publishede2024JB029075OST3 Vicino alla fagliaJCR Journa
Ionospheric Nowcasting Over Italy Through Data Assimilation: A Synergy Between IRI UP and IONORING
No full textAn accurate modeling of the ionosphere electron density is pivotal to guarantee the effective
operation of communication and navigation systems, particularly during Space Weather events. Despite the
crucial contribution of empirical models like the International Reference Ionosphere (IRI), their limitations in
predicting ionospheric variability, especially under geomagnetically disturbed conditions, are acknowledged.
The solution proposed in this work involves integrating real‐time, spatially distributed ionospheric
measurements into climatological models through data assimilation. To enhance our predictive capabilities, we
present an upgrade of the IRI UP data‐assimilation method, incorporating real‐time vertical total electron
content (vTEC) maps from the IONORING algorithm for nowcasting ionospheric conditions over Italy. This
approach involves updating the IRI F2‐layer peak electron density description through ionospheric indices, to
finally produce real‐time maps over Italy of the ordinary critical frequency of the F2‐layer, foF2, which is crucial
for radio‐propagation applications. The IRI UP–IONORING method performance has been evaluated against
different climatological and nowcasting models, and under different Space Weather conditions, by showing
promising outcomes which encourages its inclusion in the portfolio of ionospheric real‐time products available
over Italy. The validation analysis highlighted also what are the current limitations of the IRI UP–IONORING
method, particularly during nighttime for severely disturbed conditions, suggesting avenues for future
enhancements.INGV “Pianeta Dinamico— ATTEMPT” project (D53J19000170001) funded by the Italian Ministry of University and research (MUR).Publishede2023SW003838OSA3: Climatologia e meteorologia spazialeJCR Journa
Comparative analysis of bulk and velocity-derived density data in deep wells in the Adriatic Region (Italy)
No full textThis work is based on a systematic comparison between two datasets related to density data of
geological formations crossed in 13 deep wells. The wells are located in the Adriatic area and reach
depths of over 5000 meters. The main lithologies involved include sandstones, marls, clays, evaporite,
and carbonate rocks. The first dataset concerns density values obtained from the analysis of sonic
logs recorded along the wells, by applying the Gardner relation. The second dataset, on the other
hand, refers to actually acquired density log measurements. Differences among the values in the two
datasets have been calculated. The aim behind this work is to assess the reliability of rock densities
estimated using the Gardner equation by comparing them to measurements obtained through density
logs, despite many factors influencing the log density. This comparison of the densities obtained
from various lithologies and geological formations leads us to draw, in this region, some initial
considerations regarding the applicability and accuracy of Gardner formula, usually considered as
standard reference, since the density log is generally available only within the reservoir. In the area
we analyzed it is observed that the density values estimated from sonic velocities are underestimated
for the Plio-Quaternary formations characterized by clayey-sandy lithologies by at least 0.1 g/cm3;
whereas, densities of the carbonate sequences are overestimated by the same extent. Noteworthy,
the density estimates deviate from the real values especially for gypsum units, overestimating by a
factor of approximately 0.3 g/cm3. The results we obtained emphasize differences in density values
when using the Gardner formula and suggest the need for taking into account the possible errors in
the specific geological context or instead lithologies, such as those explored in this study.PublishedGT212JCR Journa
Stable isotope composition and airborne concentration of CO 2 in Rome capital city (Italy)
No full textAirborne CO2 has played a pivotal role in maintaining the Earth's atmospheric temperature at reasonable levels throughout its history. Since the onset of the industrial revolution, the level of airborne CO2 has surged due to the combustion of hydrocarbons, leading to global warming. Hydrocarbon consumption is predominantly concentrated in metropolitan areas, driven by various human activities. Estimations of CO2 emissions into the atmosphere rely on the growth of electrical power generation through hydrocarbon combustion. This study presents the outcomes of direct measurements of stable isotope concentrations in airborne CO2 in the urban area of Rome, Italy. We focused on Rome capital city, because i) it is the most populous municipality in Italy (2.8 millions inhabitants), ii) it is the European municipality with the largest surface of green areas and iii) in its south-east sector it borders the Colli Albani quiescent volcano. The dataset encompasses stable isotope compositions and airborne CO2 concentrations gathered to investigate variations in CO2 emissions across space and time. The spatial survey conducted throughout Rome's urbanized area, on a 250 km long path, aims to pinpoint the relevant sources of CO2 based on the stable isotope signature. Results reveal that the combustion of fossil fuels, stemming from urban mobility and household heating, constitutes the predominant source for the excess of airborne CO2 across a wide area of Rome centre. On the contrary, within the Rome south-east sector, including Colli Albani periphery, the carbon isotopic signature of airborne CO2 discloses the endogenous origin of the gas emissions. Continuous monitoring was carried out by the installation of an isotope analyser in three specific points of interest throughout Rome: the busiest area of the city centre, the woodland urban park of Villa Ada and the endogenous gas emission of Cava dei Selci. Findings unveil cyclic variations in human-related CO2 emissions in the city centre. The highest concentrations of airborne CO2 coincide with rush hours during morning and evening. The urban park is not affected by anthropic CO2 and its trend displays the typical day-night cycle. At Cava dei Selci we found high CO2 concentrations by a volcanic source and variations in the urban area correlate with changes in environmental conditions, such as wind speed and direction.PublishedVienn
Excess degassing drives long-term volcanic unrest at Nevado del Ruiz
No full textThis study combines volcanic gas compositions, SO2 flux and satellite thermal data collected at Nevado del Ruiz between 2018 and 2021. We find the Nevado del Ruiz plume to have exhibited relatively steady, high CO2 compositions (avg. CO2/ST ratios of 5.4 ± 1.9) throughout. Our degassing models support that the CO2/ST ratio variability derives from volatile exsolution from andesitic magma stored in the 1-4 km depth range. Separate ascent of CO2-rich gas bubbles through shallow (< 1 km depth), viscous, conduit resident magma causes the observed excess degassing. We infer that degassing of ~ 974 mm3 of shallow (1-4 km) stored magma has sourced the elevated SO2 degassing recorded during 2018-2021 (average flux ~ 1548 t/d). Of this, only < 1 mm3 of magma have been erupted through dome extrusion, highlighting a large imbalance between erupted and degassed magma. Escalating deep CO2 gas flushing, combined with the disruption of passive degassing, through sudden accumulation and pressurization of bubbles due to lithostatic pressure, may accelerate volcanic unrest and eventually lead to a major eruption.Published1230OSV1: Verso la previsione dei fenomeni vulcanici pericolosiJCR Journa
«Se dice etiam per teremoti esser sommerso et ruinato tre terre» (How a large historical earthquake was born)
No full textThere was once a physician (called Andrea Alpago or Maestro Andrea da Belluno, from his NE Italy hometown) who went to work for the Venetian consulate in Damascus around 1487, stayed there up to 1517, learned Arabic and was the first European ever to translate Avicenna’s works from the original (Levi della Vida, 1960). Thanks to his linguistic skills Maestro Andrea became an expert advisor on the political and commercial situation of the entire East (from Egypt and Turkey to Arabia and India) and in particular on the “Signor Sophi” or “Suffi”, i.e. the Shah of Persia Ismā'īl, founder of the Safawid dynasty (1502-1524), whose alliance Venice was then seeking to obtain against the Turks. Between 1504 and 1514, Maestro Andrea sent to the Venetian government many confidential reports, that were copied by Marino Sanudo in his Diarii (De Bertoldi, 1888). In a report dated on 10 March 1514, Mastro Andrea, describes at length the doings of the new Turkish sovereign, Selim I “the Grim”, in Anatolia (he was liquidating all his internal enemies – namely his stepbrothers and nephews - before starting a war against Egypt and Persia). The report ends, as an afterthought, with this piece of information: “Se dice etiam per teremoti esser sommerso e ruinato tre terre del Soltan a li confini del Turcho, videlicet Malathia et Terso et Adena”.
This is the earliest, and only contemporary testimony of an earthquake about which very little is known. It must have happened before the letter was written, but was it in late 1513 or early 1514? It heavily damaged (as shown by the verbs “submerged” and “ruined”) at least three towns of SE Anatolia, but it seems curious that two of them - Tarsus and Adana - are close to each other, while the third – Malatya – is more than 300 km away (Fig. 2). What happened in between? Could someone - either Maestro Andrea who wrote by hearsay (“se dice”) or Sanudo who copied him - have made a mistake in trascribing one of these names? Could some other place-name have been wrongly transcribed as “Malatya”?
Sanudo copied the information on the earthquake, saving it for future use. It surfaced, with literary flourishes, in a Venetian chronicle of the years 1512-1514 (Barbaro, 16th c.), and after this chronicle was published (1842) in a 19th century geological treatise (Abich, 1882) that in its turn was one of the sources for Calvi (1941). Seismological studies and catalogues then followed in Calvi’s wake, locating the earthquake either generically in “Cilicia” (the region to which Tarsus and Adana belong), or in Malatya, with Io 6 (Ergunay et al., 1967) or 7 (Soysal et al., 1981). Them came Ambraseys (1989), that went back to the somewhat romanced narration provided by Barbaro (16th c.), calculating Mw 7.4 and locating the epicentre not far from Maras, on the Pazarcik segment of the Eastern Anatolian Fault with I=IX (maximum intensity observed… but where?).
Subsequent seismological literature on the Eastern Anatolian Fault, both before and since the 2023 earthquake took and still takes the interpretation of the 1513 or 1514 earthquake provided by Ambraseys (1989) as absolute truth: the 1514 earthquake must have been located near Maras, with a M 7 at least and be a most likely predecessor of the February 2023 earthquake. Yet Ambraseys had changed his mind on this account, concluding that “without further details this information is insufficient to indicate the precise date and area over which this earthquake was felt” (Ambraseys, 2009). And, looking back to the original source of information on it, one must surely agree with him.
And how many such “large” earthquakes, based on information as poor as this, could be still taken for granted by overconfident geologists and seismologists, only because they happen to fit with some cherished theory?UnpublishedFerraraOST1 Alla ricerca dei Motori Geodinamic
One or two frequencies? The Iterative Filtering answers
No full textThe Iterative Filtering method is a technique aimed at the decomposition of non-stationary and non-linear signals into simple oscillatory components. This method, proposed a decade ago as an alternative technique to the Empirical Mode Decomposition, has been used extensively in many applied fields of research and studied, from a mathematical point of view, in several papers published in the last few years. However, even if its convergence and stability are now established both in the continuous and discrete setting, it is still an open problem to understand up to what extent this approach can separate two close-by frequencies contained in a signal.
In this paper, first we recall previously discovered theoretical results about Iterative Filtering. Afterward, we prove a few new theorems regarding the ability of this method in separating two nearby frequencies both in the case of continuously and discrete sampled signals. Among them, we prove a theorem which allows to construct filters which captures, up to machine precision, a specific frequency. We run numerical tests to confirm our findings and to compare the performance of Iterative Filtering with the one of Empirical Mode Decomposition and Synchrosqueezing methods. All the results presented confirm the ability of the technique under investigation in addressing the fundamental “one or two frequencies” question.Published128322OSA3: Climatologia e meteorologia spazialeJCR Journa
Marine Environments in Front of the Ancient City of Pompeii (Southern Italy) at 79 CE: New Insights for the Unknown Location of the Harbour
No full textA multidisciplinary study, including geomorphological, stratigraphic, paleontological and archaeological methods and techniques, allowed for a detailed exploration of coastal landforms and environments in front of the ancient city of Pompeii (southern Italy). The famous site of Pompeii sits on a small volcanic hill in the alluvial-coastal plain of the Sarno River, very close to the ancient paleoshoreline. When the Roman city was buried during the eruption of Vesuvius in 79 CE, pyroclastic fall and flow deposits covered the urban centres and ancient coastal landforms. In this study, 83 new boreholes were carried out up to a depth of 10 m. Some of them (15) were analysed for their sedimentological, stratigraphical and paleontological characterisation, in order to reconstruct the sedimentary environments in 79 CE. The data collected allow for new hypotheses to be formulated regarding the paleoshorelines, as well as the 79 CE coastal landforms and environments. In particular, litho-stratigraphic and fossil assemblages highlight the presence of shallow marine environments in a large back-ridge depression, named Masseria Curati, that is located just outside the city walls. This hypothesis opens new insights on the unknown location of the harbour of the Roman city.Published1198JCR Journa