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Investigating a Possible Correlation between NOAA-Satellite-Detected Electron Precipitations and South Pacific Tectonic Events
No full textOn 4 March 2021, a devastating M8.1 earthquake struck the Kermadec Islands of New Zealand. Given the tremendous energy released during the event, we sought to investigate the event’s potential impact on the ionosphere and the inner Van Allen Belt using data from the high-energy electron detectors on board the NOAA-18 satellite. The survey was also extended to the strongest shallow M6.5+ earthquakes occurring between 150° and 190° in longitude, and between −5° and −35° in latitude over the previous ten years. In nearly all cases, evident electron fluxes entering the loss cone were observed. To explore the possibility of a connection between ionospheric signals and tectonic events in this intensely active region, we analyzed electron losses from the inner Van Allen Belt, taking into account latitude, longitude, day/night times, and proximity to the South Atlantic Anomaly. Compared to previous studies, here only the most significant loss phenomena persistent in the ionosphere were considered. Particular interest was reserved for the intense electron loss events that had a duration spanning from a few to several minutes and occurred several hours before and after strong seismic events. Thereafter, time series of electron counting rates and strong Southern Pacific earthquakes were transformed into binary series, and the series multiplication was investigated. The results suggest four peaks of association, including a first couple between electron perturbations detected for ascending semi-orbits and seismic events and a second one between electron perturbations detected in the southern ionosphere and seismic events. They both anticipated the occurrence of earthquakes, occurring around 4 h before them. Other couples were observed between electron perturbations detected for descending semi-orbits and seismic events and between electron perturbations detected in the northern ionosphere and seismic events. They both occurred around 3 h after the occurrence of earthquakes. The case of perturbations anticipating seismic events has the intriguing properties of sustaining the hypothesis that a physical interaction occurred around 6 h before seismic events as in the West Pacific case. A physical model of electrons detected far several thousands of km from the earthquake epicenters was also presented. However, a simulation of random seismic events suggested that the null hypothesis cannot be fully rejected for these associations, prompting many more analyses and case studies.Published1059OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
ELICIPY 1.0: A Python online tool for expert elicitation
No full textStructured expert judgment is crucial when dealing with significant epistemic and aleatoric uncertainties, particularly in probabilistic hazard assessments, where decisions based on uncertain information are often critical. In structured expert elicitations, participants are asked to quantify their uncertainty judgments by providing their percentile estimates of numerical values for a set of questions. More specifically, performance-based elicitations start with ‘‘seed’’ questions for determining experts’ uncertainty quantification skill. The performance scores are thus used to define each expert’s weight to be applied when considering their judgments on ‘‘target’’ questions, i.e., the actual variables of interest for the case study. In this paper we describe ELICIPY, a new Python tool which allows to perform expert elicitation sessions in a framework that covers both the questionnaire collection and the analysis parts, an approach that simplifies the work normally done by the analyst(s). This is achieved through the automatic generation of online webforms to collect the experts’ answers, their check for consistency and, finally, their analysis using different weighting schemes. The tool automatically produces outputs in different formats and creates a pptx presentation file available just after the collection of the answers.Published101641OSV4: Preparazione alle crisi vulcanicheJCR Journa
Paleomagnetism of the Peloritan Terrane (NE Sicily): From Greater Iberia to the Neo Apennine‐Maghrebide Arc
No full textCalabria and the Peloritan Mts. of NE Sicily are exotic terranes predominantly formed by Hercynian rocks interrupting the Meso-Cenozoic sediments exposed along Apennine-Maghrebide chains. Dual-polarity pre-tilting magnetization direction retrieved from 5 Jurassic, 5 upper Cretaceous-Eocene, and 4 upper Oligocene sedimentary sites from external-intermediate Peloritan nappes yield 99° ± 12°, 131° ± 15°, and 138° ± 12° (respectively) clockwise (CW) rotations with respect to Europe. Upper Cretaceous-Oligocene values are similar to the ∼130° CW late Miocene-Early Pleistocene rotation previously documented on internal Maghrebian nappes of W Sicily. Jurassic data imply a ∼30° Early Cretaceous counterclockwise (CCW) rotation, similar for sign, magnitude, and timing to Iberia rotation, proving that the Peloritan crust was part of Greater Iberia before its <30 Ma fragmentation and dispersal. Furthermore, 20 Jurassic-Oligocene sites yield post-tilting overprint direction (later rotated up to 60° CW) that was acquired synchronous to late Miocene-Pleistocene rotation. The Peloritan rotation is completely different from the 160° post-late Jurassic CCW rotation documented on NE Calabria, and demonstrates that the two terranes underwent independent drift histories. Lack of a Sardinian rotation fingerprint (90° CCW between 30 and 15 Ma) suggests that the Peloritan terrane lied S of the Calabria-Sardinia CCW rotating system, at the non-rotational apex of an Oligocene-early Miocene “Paleo Apennine-Maghrebide Arc.” The Peloritan terrane was stacked onto the African margin and incorporated in the Maghrebian chain in mid Burdigalian (18–17 Ma). Afterward, it formed the S limb of the “Neo Apennine-Maghrebide Arc,” and was passively carried on top of CW rotating Maghrebide nappes during late Miocene-Early Pleistocene (12–1 Ma).Publishede2023TC008128OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioJCR Journa
Preface
No full textWith this volume, Annals of Geophysics proudly presents a special issue dedicated to celebrating the anniversary of Istituto Nazionale di Geofisica e Vulcanologia (INGV) for its "25 years of geosciences for society". This collection of scientific articles is authored by dedicated researchers whose active participation and collaboration have brought prestige to both INGV and our journal. Although the list of authors is not exhaustive among the numerous past and present INGV collaborators, it offers an exciting and insightful journey through the fields of seismology, volcanology, and environmental science. This volume is divided into three parts: the first is dedicated to topics more closely related to seismology, the second to volcanology, and the last part is focused on environmental issues, including both review articles and articles addressing specific problems. There are contributions dedicated to the study of tsunamis and multi-hazard analyses, as well as articles on the history of globally significant infrastructure and sections focused on the most widely used seismological models.INGVPublishedP426OS: Terza missioneJCR Journa
An Update of the NeQuick-Corr Topside Ionosphere Modeling Based on New Datasets
No full textA new analytical formula for H0, one of the three parameters (H0, g, and r) on which the
NeQuick model is based to describe the altitude profile of the electron density above the F2-layer
peak height hmF2, has recently been proposed. This new analytical representation of H0, called
H0,corr, relies on numerical grids based on two different types of datasets. On one side, electron density
observations by the Swarm satellites over Europe from December 2013 to September 2018, and
on the other side, IRI UP (International Reference Ionosphere UPdate) maps over Europe of the
critical frequency of the ordinary mode of propagation associated with the F2 layer, foF2, and hmF2,
at 15 min cadence for the same period. The new NeQuick topside representation based on H0,corr,
hereafter referred to as NeQuick-corr, improved the original NeQuick topside representation. This
work updates the numerical grids of H0,corr by extending the underlying Swarm and IRI UP datasets
until December 2021, thus allowing coverage of low solar activity levels, as well. Moreover, concerning
Swarm, besides the original dataset, the calibrated one is considered, and corresponding
grids of H0,corr calculated. At the same time, the role of g is investigated, by considering values different
from the reference one, equal to 0.125, currently adopted. To understand what are the best
H0,corr grids to be considered for the NeQuick-corr topside representation, vertical total electron content
data for low, middle, and high latitudes, recorded from five low-Earth-orbit satellite missions
(COSMIC/FORMOSAT-3, GRACE, METOP, TerraSAR-X, and Swarm) have been analyzed. The updated
H0,corr grids based on the original Swarm dataset with a value for g = 0.15, and the updated
H0,corr grids based on the calibrated Swarm dataset with a value for g = 0.14, are those for which the
best results are obtained. The results show that the performance of the different NeQuick-corr models
is reliable also for low latitudes, even though these are outside the spatial domain for which the
H0,corr grids were obtained, and are dependent on solar activity.Published498OSA3: Climatologia e meteorologia spazialeJCR Journa
Multiparametric stations for real-time monitoring and long-term assessment of natural hazards
No full textThe present work would like to illustrate a new concept of multiparametric
stations to characterize the crustal fluids-tectonic interaction in specific
geological contexts. The dynamics of crustal fluids in relation to tectonics is
a complex and sometimes intricate issue. Several factors act and mutually
influence themselves, so that in each tectonic and geological context they
follow a specific behavior, and a comprehensive cause-effect rule is hard to
find. Changes in water chemistry and levels and in soil flux regimes (e.g.,
CO2, CH4, radon) are just a few examples well documented in the literature
as being pre-, co- and post-seismic modifications as well as being markers
of the local tectonic stress acting in the crust. A regional study combined
with a long-lasting multiparametric monitoring is needed to prepare to a
seismic sequence in a given place. The field infrastructure was set up starting
from the end of 2021, and multiparametric stations have been installed in
correspondence of active seismogenic sources initially located in Northern Italy.
Data are transmitted in real-time and archived in an ad hoc developed relational
database. Monitoring is mainly focused on groundwater parameters (water level,
temperature, and electrical conductivity) of aquifers showing distinct degrees
of confinement and lithologies. Sites are also equipped of meteorological
sensors (pressure, temperature, rain, humidity, wind speed and direction), radon
sensors and surface and borehole seismic stations providing accelerometric
and velocimetric data. A mud volcano field is also monitored and holds the
installation of a permanent CO2 soil flux station. A statistical analysis working
flow is also proposed for a preliminary evaluation of the acquired time-series.
In particular, a couple of tools to detect, and thus filter, anthropogenic and
meteorological effects on a groundwater level series is described. We wish to
provide a model of approach to analogous study cases in other potentially
seismic areas.Published1412900JCR Journa
The 2 December 2020 MW 4.6, Kallithea (Viotia), central Greece earthquake: a very shallow damaging rupture detected by InSAR and its role in strain accommodation by neotectonic normal faults
No full textOn 2 December 2020 10:54 UTC a shallow earthquake of MW (NOA) = 4.6 occurred near the village of Kallithea (to the east of Thiva), central Greece, which, despite its modest size, was locally damaging. Using InSAR and GNSS data, we mapped a permanent change on the ground surface, i.e., a subsidence of 7 cm. Our geodetic inversion modelling indicates that the rupture occurred on a WNW–ESE striking, SSW-dipping normal fault, with a dip-angle of ~ 54°. The maximum slip value was 0.35 m, which was reached at a depth of about 1100 m. The analysis of broadband seismological data also provided kinematic source parameters such as moment magnitude MW = 4.6 (± 0.1), rupture area 6.3 km2 and mean slip 0.16 m, which agree with the values obtained from the geodetic model. The effects of the earthquake were disproportionate to its moderate magnitude, probably due to its unusually shallow depth (slip centroid at 1.1 km) and the high efficiency of the earthquake (radiation efficiency
= 0.62). The geodetic data inversion also indicates that within the uncertainty limits of the technique, three scenarios are possible (a) the earthquake responsible for the mapped surface deformation may have occurred on a ~ 2-km long, blind normal fault different from the well-known active Kallithea normal fault or (b) could have occurred along a secondary fault that branches off the Kallithea fault or (c) it may have occurred along the Kallithea fault itself, but with its geometrical configuration could not be modelled with available data. We have also concluded that with a high dip-angle Kallithea Fault forward model it is not possible to fit the geodetic data. The rupture initiated at a very shallow depth (1.1 km) and it could not propagate deeper possibly because of a structural barrier down-dip. The 2020 event near Kallithea highlighted the structural complexity in this region of the Asopos Rift valley as the reactivation of the WNW–ESE structures indicates their significant role in strain accommodation and that they still represent a seismic hazard for this region.Published1523–1541OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Calcareous Nannofossil variability controlled by Milankovitch and sub-Milankovitch periodicity in the Monte San Nicola section (Gelasian GSSP / MIS 100–104)
No full textThe Quaternary marks the beginning of the ice ages, with the establishment of a stable Northern Hemisphere ice sheet. The Monte San Nicola section, southern Sicily (Italy) is the Global Boundary Stratotype Section and Point of the Gelasian Stage of the Lower Quaternary Subseries and is attracting new attention for providing valuable information on paleoclimate evolution.
Here we present a paleoenvironmental reconstruction based on new data from calcareous nannoplankton, the phytoplankton organisms that are sensitive to sea surface changes and water column dynamics. We adopt statistical and signal analysis to support our paleoenvironmental model. The most evident paleoenvironmental signal throughout the investigated interval is the contrast between the abundance patterns of placoliths and F. profunda, the former pointing to surface productivity (water column mixing, shallow nutricline), the latter to the establishment of a deep nutricline. The observed nutricline depth shift occurred with a regular precessional pace, following Northern Hemisphere summer insolation and, likely, North African monsoon activity. A significant periodicity of 8 kyr, in tune with late Quaternary Heinrich events, is also observed in nannoplankton taxa, supporting previous findings on the existence of suborbital climatic variability even at the Pliocene-Pleistocene transition.Published102397OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioOSA2: Evoluzione climatica: effetti e loro mitigazioneJCR Journa
SEISMONOISY: A Quasi-Real-Time Seismic Noise Network Monitoring System
No full textThis paper introduces SEISMONOISY, an application designed for monitoring the spatiotemporal characteristic and variability of the seismic noise of an entire seismic network with a quasi-real-time monitoring approach. Actually, we have applied the developed system to monitor 12 seismic networks distributed throughout the Italian territory. These networks include the Rete Sismica Nazionale (RSN) as well as other regional networks with smaller coverage areas. Our noise monitoring system uses the methods of Spectral Power Density (PSD) and Probability Density Function (PDF) applied to 12 h long seismic traces in a 24 h cycle for each station, enabling the extrapolation of noise characteristics at seismic stations after a Seismic Noise Level Index (SNLI), which takes into account the global seismic noise model, is derived. The SNLI value can be used for different applications, including network performance evaluation, the identification of operational problems, site selection for new installations, and for scientific research applications (e.g., volcano monitoring, identification of active seismic sequences, etc.). Additionally, it aids in studying the main noise sources across different frequency bands and changes in the characteristics of background seismic noise over time.Published3474JCR Journa
The NE-SW Sibari fault zone: A seismic hazard source in Ionian Northern Calabria (Italy)
No full textA multidisciplinary approach including archaeological, geophysical, and geological/geomorphological surveys
provided pieces of evidence that allowed us to identify the Sibari fault zone (SFZ) in Northern Calabria (Italy).
The SFZ runs in a ~ NE-SW direction for a length of ~18 km from the Ionian coastline to Terranova da Sibari and
has an oblique normal-dextral kinematics. The envelope of the SFZ is derived from several direct and indirect
evidence resulting in subparallel and locally en-echelon fault traces over a maximum 500 m-wide band, running
at different elevations across hills and flat lands. The SFZ was active since at least the Middle-Upper Pleistocene,
producing faulting of alluvial deposits, marine terraces, drainage incisions, and the archaeological structures of
Sybaris. Given the fault length and assuming a seismogenic behavior, the SFZ is a primary earthquake source
possibly producing moderate to large earthquakes (M ≥ 6). We calculated the average slip rates along the SFZ
based on the ages and on the accumulated displacements of offset streams and marine terraces. The estimates are
of 0.05–0.18 mm/yr and 0.41–0.70 mm/yr for vertical and dextral slip, respectively. Based on both the measured
(min. 30 cm) and the expected value (av. 40 cm) of lateral slip per event, we infer an average recurrence for
surface faulting events on the SFZ of about 700–1000 yrs. The most recent surface faulting earthquake occurred
on the fault is dated 1300–1100 yrs. ago, highlighting that the elapsed time approaches the estimated average
recurrence. Considering these findings, the newly recognized SFZ should be included among the faults that
contain a potential seismic hazard in this poorly known portion of the Ionian sector of northern Calabria.Published230214OST2 Deformazione e Hazard sismico e da maremotoJCR Journa