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Tectonic-Sedimentary evolution of the Tuscan shelf (Italy): Seismic-stratigraphic/structural analysis of Neogenic succession in the Tyrrhenian Sea between Elba Island and Monte Argentario promontory
No full textbetween Elba Island and Monte Argentario promontory, was performed to reappraise the Tuscan shelf tectonic
evolution. Despite the almost flat geometry of the seafloor, seismic profiles show a corrugated morphology of the pre-neogenic deformed acoustic basement, organized in structural highs and narrow, mostly N-S and NNW-SSE basins. We identified an intimate relationship between the thrust-related structural highs and the position of the basins, principally located at the forelimb and backlimb of major antiforms, a legacy of a primarily Miocene compressional stage. During the middle Miocene, the Tyrrhenian Sea opening set up, and the extensional front migrated from west to east, progressively activating and deactivating the observed high-angle faults, blandly controlling the sedimentation within the basins. After the late Messinian, a regional collapse stage led to the deepening and widening of the basins. A progressive deactivation of all the normal faults is recorded from the lower Pliocene. After the Late Pliocene/early Pleistocene, the area turned into a passive and widespread sinking stage without any frank tectonic activity. Results show that regional thrusts shaped the main architecture of the Tuscan Shelf shallow crust, while the neogenic depocenters started to develop as thrust-top basins along the flanks of the inherited antiforms. Intriguingly and partially in contrast with previous works, no evidence of lowangle normal fault was observed. We propose an innovative model that poses new questions on the crustal-scale mechanisms responsible for Tyrrhenian extensional process-related features, also establishing a new and unique starting point for fully unraveling the tectonic evolution of this portion of central Italy's offshore domain.Published230211OST1 Alla ricerca dei Motori GeodinamiciJCR Journa
Unveiling spatial variations in atmospheric CO sources: a case study of metropolitan area of Naples, Italy.
No full textIn the lower atmosphere, CO emissions impact human health and ecosystems, making data at this level essential for addressing carbon-cycle and public-health questions. The atmospheric concentration of CO is crucial in urban areas due to its connection with air quality, pollution, and climate change, becoming a pivotal parameter for environmental management and public safety. In volcanic zones, geogenic CO profoundly affects the environment, although hydrocarbon combustion is the primary driver of increased atmospheric CO and global warming. Distinguishing geogenic from anthropogenic emissions is challenging, especially through air CO concentration measurements alone. This study presents survey results on the stable isotope composition of carbon and oxygen in CO and airborne CO concentration in Naples' urban area, including the Campi Flegrei caldera, a widespread hydrothermal/volcanic zone in the metropolitan area. Over the past 50 years, two major volcanic unrests (1969-72 and 1982-84) were monitored using seismic, deformation, and geochemical data. Since 2005, this area has experienced ongoing unrest, involving the pressurization of the underlying hydrothermal system as a causal factor of the current uplift in the Pozzuoli area and the increased CO emissions in the atmosphere. To better understand CO emission dynamics and to quantify its volcanic origin a mobile laboratory was used. Results show that CO levels in Naples' urban area exceed background atmospheric levels, indicating an anthropogenic origin from fossil fuel combustion. Conversely, in Pozzuoli's urban area, the stable isotope composition reveals a volcanic origin of the airborne CO. This study emphasizes the importance of monitoring stable isotopes of atmospheric CO, especially in volcanic areas, contributing valuable insights for environmental and public health management.Published20483OSA2: Evoluzione climatica: effetti e loro mitigazioneOSV1: Verso la previsione dei fenomeni vulcanici pericolosiOSV3: Sviluppo di nuovi sistemi osservazionali e di analisi ad alta sensibilitàJCR Journa
Quaternary slip-rates probabilistic estimation for the Northern Apennines frontal thrust in the Po Plain (Northern Italy) by integrating surface and subsurface data
No full textThe Northern Apennines thrust front in the Po basin exhibits active blind thrusts and associated anticlines, with some anticline crests either emerging or shallowly buried beneath late Pleistocene continental deposits. This study focuses on the outcropping San Colombano Structure and its buried neighbouring Casalpusterlengo-Zorlesco Structure, representing thrust-controlled anticlines in the central part of the Po basin. We reconstruct the Pleistocene evolution of these anticlines by integrating previously published surface geological maps and subsurface geological constraints from geophysical data and boreholes. We performed a trishear inversion of the deformation observed after the decompaction of the sediments. We used the solutions of the trishear inversion to compute the probabilistic distribution of slip rates over distinct time intervals. Our findings align with previous estimations of long-term slip rates in the Po Plain during the Quaternary, revealing rates of approximately 0.63 mm/yr and 0.53 mm/yr over the past 2.4 Myr for the San Colombano and Casalpusterlengo-Zorlesco Structures, respectively. The analysis of stratigraphic markers unveils a general decrease in faults activity during the Pleistocene, with slip rates around 0.2–0.3 mm/yr in the last 0.3 Myr, along with a diverse evolution of the thrust faults governing the two anticlines. Specifically, the activity rates of the San Colombano Structure supersede that of the Casalpusterlengo-Zorlesco Structure during the Middle to Late Pleistocene, implying an out-of-sequence propagation of the San Colombano ramp-anticline in the Late Pleistocene along an oblique right-lateral transfer zone. Incorporating a probabilistic approach in slip rates calculation provides a more comprehensive handling of uncertainties. This attribute is pivotal in seismic hazard assessment analyses and understanding complex fault systems' tectonic evolution.Published230227OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
The European Volcano Observatories and their use of the aviation colour code system
No full textVolcano observatories (VOs) around the world are required to maintain surveillance of their volcanoes and inform civil protection and aviation authorities about impending eruptions. They often work through consolidated procedures to respond to volcanic crises in a timely manner and provide a service to the community aimed at reducing the potential impact of an eruption. Within the International Airways Volcano Watch (IAVW) framework of the International Civil
Aviation Organisation (ICAO), designated State Volcano Observatories (SVOs) are asked to operate a colour coded
system designed to inform the aviation community about the status of a volcano and the expected threats associated.
Despite the IAVW documentation defining the different colour-coded levels, operating the aviation colour code in a
standardised way is not easy, as sometimes, different SVOs adopt different strategies on how, when, and why to change
it. Following two European VOs and Volcanic Ash Advisory Centres (VAACs) workshops, the European VOs agreed
to present an overview on how they operate the aviation colour code. The comparative analysis presented here reveals
that not all VOs in Europe use this system as part of their operational response, mainly because of a lack of volcanic eruptions since the aviation colour code was officially established, or the absence of a formal designation as an SVO. We also note that the VOs that do regularly use aviation colour code operate it differently depending on the frequency
and styles of eruptions, the historical eruptive activity, the nature of the unrest, the monitoring level, institutional norms,
previous experiences, and on the agreement they may have with the local Air Transport Navigation providers. This study
shows that even though the aviation colour code system was designed to provide a standard, its usage strongly depends on the institutional subjectivity in responding to volcano emergencies. Some common questions have been identified across the different (S)VOs that will need to be addressed by ICAO to have a more harmonised approach and usage of the aviation colour codePublished23OSV4: Preparazione alle crisi vulcanicheJCR Journa
The seismic network of Ischia island from 1993 to 2021
No full textThe volcanic island of Ischia has shown to have an important seismogenic potential, being the location of several destructive earthquakes, e.g. 1881, 1883 and 2017. The damage caused by these earthquakes was more connected to the proximity of the source to the surface than to their magnitude (Mw < 5.2). The need to monitor and model this seismicity required the installation of a dense and modern seismic network. The first modern seismic station on the island was installed in 1993, and the network was successively increased with time. A meaningful improvement to the network was made after the earthquake that occurred on the 21 of August 2017. The network currently has 11 sites with velocimeters and some of them with accelerometers installed too. We analysed the seismic network configuration in comparison with the seismicity that characterizes the area to mark a starting point for future seismological analysis. The network is currently able to locate shallow earthquakes with duration magnitude greater or equal to 0 in the whole island.Published47-5
An archaeomagnetic study of the Ishtar Gate, Babylon
No full textData from the marriage of paleomagnetism and archaeology (archaeomagnetism) are the backbone of attempts to create geomagnetic field models for ancient times. Paleointensity experimental design has been the focus of intensive efforts and the requirements and shortcomings are increasingly well understood. Some archaeological materials have excellent age control from inscriptions, which can be tied to a given decade or even a specific year in some cases. In this study, we analyzed fired mud bricks used for the construction of the Ishtar Gate, the entrance complex to the ancient city of Babylon in Southern Mesopotamia. We were able to extract reliable intensity data from all three phases of the gate, the earliest of which includes bricks inscribed with the name of King Nebuchadnezzar II (605 to 562 BCE). These results (1) add high quality intensity data to a region relatively unexplored so far (Southern Mesopotamia), (2) contribute to a better understanding of paleosecular variation in this region, and the development of an archaeomagnetic dating reference for one of the key regions in the history of human civilizations; (3) demonstrate the potential of inscribed bricks (glazed and unglazed), a common material in ancient Mesopotamia, to archaeomagnetic studies; and (4) suggest that the gate complex was constructed some time after the Babylonian conquest of Jerusalem, and that there were no substantial chronological gaps in the construction of each consecutive phase. The best fit of our data (averaging 136±2.1 ZAm2) with those of the reference curve (the Levantine Archaeomagnetic Curve) is 569 BCE.Publishede0293014OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioJCR Journa
What about the predecessors of the February 2023 earthquakes in Eastern Anatolia?
No full textWhen large earthquakes occur, it is natural enough to wonder about their likely predecessors (if any). This is why, after the earthquakes of February 2023, we began a review of the historical seismic record of Eastern Anatolia
Our investigation concentrated on six major earthquakes/sequences occurred after 1000 AD (1003, 1114/1115, 1269, 1344, 1513/1514 and 1544). The earthquakes of 1822, 1872 and 1893 are better known and do not require priority investigation.
The geopolitical history of this region is very complex, with many changes of rulers along the centuries, but its long-term seismic history is rather well known. Many earthquakes are on record both before and since the date - some 2100 years ago - when the region became a Roman province. Many of its main towns (Aleppo and Antakya for instance) have a long-term history that includes eyewitness observations of many strong earthquakes.
Historical earthquake records for this area were collected and studied several times. The latest studies are Soysal et al. (1981), Ambraseys and Finkel (1995), Guidoboni & Comastri (2005), Sbeinati et al. (2005), Tan et al. (2008). N.N. Ambraseys wrote many papers on this subject and compendiated his work in Ambraseys (2009). However, time, epicentral location and size of many earthquakes are debatable and earthquake catalogues propose contrasting values for the same events.
Our work consisted of: a) retrieving and analyzing the main historical sources for each earthquake; b) identifying the localities mentioned in the sources and assessing macroseismic intensities from the original information; c) determining earthquake parameters (Io, Mw and - whenever possible - source azimuth) with the “Boxer” method (Gasperini et al., 1999), after properly calibrating the relevant coefficient by using recent earthquakes of the Anatolian region.
Fig. 3 presents the seismological results of this work: Mw (with uncertainty equal to 0.3) and the “boxes” obtained with the Gasperini et al. (1999) procedure and representing the surface projection of the possible earthquake sources: the epicentre is in the middle of the “box”.
The epicentral location and Mw calculated for the main earthquake of 1114 are close to those of the first event of 6 February, 2023. The “box” seems to match the Pazarcik segment of the EAFZ (we refer hereafter to the fault definitions used by Duman and Emre, 2013 and by Duman et al., 2018). The 1269 earthquake was less energetic than the 1114 one, and its parameters are less well constrained. Its “box” suggests the Amanos segment as the likeliest source, with the Toprakkale segment as an alternative candidate. The 1344 earthquake is rather well known and was indeed a very large one. On account of its location it was not considered in the debate on the 2023 earthquake source. However, the identification of its source would be helpful for the understanding of seismicity in this region. As for the 1513/1514 earthquake, the first interpretation by Ambraseys (1988) was -and still is – considered as the absolute truth by literature, leading to a strong connection with the Pazarcık segment. Unfortunately, this interpretation is founded on poor information, as later stated by Ambraseys (2009) and confirmed by us. Though we cannot provide reliable epicentral location and magnitude estimates, we believe that the Toprakkale or Karataş segments could represent a more appropriate option for the source. Similar considerations can be proposed for the 1544 earthquake, whose informative background is also very weak. It could be located in the area where the recent M7.6 took place (Çardak fault), with Mw around 6.9.UnpublishedFerraraOST1 Alla ricerca dei Motori Geodinamic
Drought‐Induced Vertical Displacements and Water Loss in the Po River Basin (Northern Italy) From GNSS Measurements
No full textWe study vertical ground displacement time series from Global Navigation Satellite System (GNSS) stations to measure deformation associated with hydrological drought in the Po river basin. Focusing on interannual trend changes, rather than seasonal (annual) components, we found a clear spatially correlated deformation signal that is temporally (anti)correlated with changes in the Po river level and the SPEI-12 drought index, with stations moving upward during periods of river/index level decrease and vice versa. In the 2021–2022 time span, which culminated in the most severe drought of the last two centuries, we estimate the amount and spatial distribution of water loss in the basin and its surroundings. Excluding the seasonal signals, between January 2021 and August 2022, the GNSS stations underwent uplift, up to 7 mm, which corresponds to ∼70 Gtons of water loss. Compared to Global Land Data Assimilation System and Gravity Recovery and Climate Experiment estimates, GNSS results show a similar temporal evolution of water content but a more heterogeneous distribution of values. We show that continuous GNSS networks provide an effective way to monitor multiannual trend changes in water storage even in small water basins and serve as a reliable indicator of drought severity.Publishede2023EA003326OSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
Characterisation and locations of volcanic high frequency tremor above 10 Hz on Mount Etna
No full textWhen it comes to volcanic tremor, low frequency signals (below 5 Hz) are well investigated. Such tremor signals can usually be linked to magma movement or gas fluctuations. However, little is known about seismic tremor signals on Mount Etna above 10 Hz. Hence, a large field campaign targeting high frequencies was undertaken in the summer of 2022. It consisted of the deployment of six dense circular arrays ranging from 30 to 200 m apertures of seismic nodes installed around the summit craters. It led to the detection of tremor bands between 10 and around 20 Hz as well as the typical tremor signals below 5 Hz.
The tremor is detected with good coherency at stations within one array (despite an extreme level of scattering) in good agreement with the energy distribution in the average amplitude spectra of the array. The high frequency tremor varies strongly in intensity over time periods of one hour and re-occurs several times throughout the deployment period of almost a week. In contrast the tremor below 5 Hz is relatively constant. This suggests that the high frequency tremor could be a separate signal due to a process that may not yet be fully understood.
Localisations of these tremor episodes point to or near the Bocca Nuova Summit Crater which was actively degassing at the time. Interestingly, high frequency seismic tremor is matched in time very well by a narrow 3.5-5 Hz acoustic band. While the match in time clearly suggests a connection between the two signals, the different frequencies indicate two different but linked processes happening simultaneously. The acoustic signal implies degassing processes. Later during the deployment tremor episodes are found which are accompanied by much weaker acoustic signals (if at all present) suggesting gases might not necessarily be involved in generating the detected seismic tremor at all.
In summer 2023 we undertook a complementary second deployment of seismic, acoustic and optical camera data in the Bocca Nuova summit area. Once again, we find tremor below 5 Hz, however high frequency characteristics are different to the previous year with tremor bands less dominant than before and much more constant over time. More than one acoustic band is found as well, also constant over time. In this second data set we use camera recordings of the crater activity as a proxy for degassing activity to try and understand the precise origin of these seismic and acoustic volcanic signals.PublishedVienn
New Concept of Smart UAS-GCP: A Tool for Precise Positioning in Remote-Sensing Applications
No full textToday, ground control points (GCPs) represent indispensable tools for products’ georeferencing in all the techniques concerning remote sensing (RS), particularly in monitoring activities from unmanned aircraft system (UAS) platforms. This work introduces an innovative tool, smart GCPs, which combines different georeferencing procedures, offering a range of advantages. It can serve three fundamental purposes concurrently: (1) as a drone takeoff platform; (2) as a base station, allowing the acquisition of raw global navigation satellite system (GNSS) data for post-processed kinematic (PPK) surveys or by providing real-time GNSS corrections for precision positioning; (3) as a rover in the network real-time kinematic (NRTK) mode, establishing its position in real time with centimetric precision. The prototype has undergone testing in a dedicated study area, yielding good results for all three geodetic correction techniques: PPK, RTK, and GCP, achieving centimeter-level accuracy. Nowadays, this versatile prototype represents a unique external instrument, which is also easily transportable and able to connect to the GNSS RING network, obtaining real-time positioning corrections for a wide range of applications that require precise positioning. This capability is essential for environmental applications that require a multitemporal UAS-based study. When the real-time RING data are accessible to the scientific community operating in RS surveying, this work could be a helpful guide for researchers approaching such investigations.Published123OST5 Verso un nuovo MonitoraggioJCR Journa