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Effects on a Deep-Learning, Seismic Arrival-Time Picker of Domain-Knowledge Based Preprocessing of Input Seismograms
No full textAutomated seismic arrival picking on large and real-time seismological waveform datasets is fundamental for monitoring and research. Recent, high-performance arrival pickers apply deep-neural-networks to nearly raw seismogram inputs. However, there is a long history of rule-based, automated arrival detection and picking methods that efficiently exploit variations in amplitude, frequency and polarization of seismograms. Here we use this seismological domain-knowledge to transform raw seismograms as input to a deep-learning picker. We preprocess 3-component seismograms into 3-component characteristic functions of a multi-band picker, plus modulus and inclination. We use these five time-series as input instead of raw seismograms to extend the deep-neural-network picker PhaseNet. We compare the original, data-driven PhaseNet and our domain-knowledge PhaseNet (DKPN) after identical training on datasets of different sizes and application to in- and cross-domain test datasets. We find DKPN and PhaseNet show near identical picking performance for in-domain picking, while DKPN outperforms PhaseNet for some cases of cross-domain picking, particularly with smaller training datasets; additionally, DKPN trains faster than PhaseNet. These results show that while the neural-network architecture underlying PhaseNet is remarkably robust with respect to transformations of the input data (e.g. DKPN preprocessing), use of domain-knowledge input can improve picker performance.Istituto Nazionale di Geofisica e Vulcanologia Grant numbers CUP D53J1900017001
HORIZON EUROPE Marie Sklodowska-Curie Actions Grant numbers 101105516Published1164OST5 Verso un nuovo MonitoraggioN/A or not JC
Investigation of the global climatologic performance of ionospheric models utilizing in-situ Swarm satellite electron density measurements
No full textThe Swarm constellation is a triplet of satellites, flying, since their final configuration reached in April 2014, at altitudes of about 420
to 490 km (the lower pair) and about 500 to 530 km (the upper satellite). All the three satellites provide in-situ measurements of the
plasma density in the topside ionosphere using Langmuir Probe sensors onboard the Electrical Field Instrument. The present study is
a comprehensive investigation into the climatologic performance of three ionospheric models when compared to the Swarm satellite
in-situ measurements. The models are the International Reference Ionosphere (IRI) model, a quick run ionospheric electron density
model (NeQuick), and a 3-dimensional electron density model based on artificial neural network training of COSMIC (Constellation
Observing System for Meteorology, Ionosphere, and Climate) satellites radio occultation measurements (3D-NN). The mean monthly
quiet-time latitudinal profile of Swarm measurements was computed by binning the Swarm electron density measurements in 15-
degree longitudes starting from longitude 180 in steps of 15 to 180 , and corresponding model predictions were obtained. The data
used in the study covers the years 2014, 2016, 2019, and 2022, capturing various phases of the solar activity cycle. Results from the study
show that modelled electron density predictions from all three climatologic models are fairly good representations of the Swarm satellite
measurements, with some exceptions in which the models underestimate or overestimate the Swarm satellite values. The IRI model performed
best at the northern hemisphere mid latitude, and it overestimated the Swarm measurements at altitudes of 450 km, especially
at the southern hemisphere mid and high latitudes. The NeQuick performed best during the night times, and it overestimated the Swarm
measurements, especially at the mid latitudes. The NeQuick was also observed to overestimate the Swarm measurements during the winter
solstices at both hemispheres, which is June solstice in the southern hemisphere and December solstice in the northern hemisphere.
Overall, the 3D-NN model most often performed better than the IRI model and the NeQuick, especially during the day times and during
the high solar activity year (2014), but it underestimated the Swarm measurements, especially at the low and mid latitudes. For all categories
explored in the study, the 3D-NN consistently performed better than the other two models. The NeQuick performed better thanIn pressOSA3: Climatologia e meteorologia spazialeJCR Journa
Chlorine to sodium ratio as an empiral geochemical estimator of obsidian aging
No full textThis work is an extension of previous research in which we successfully tested the effectiveness
of chlorine (Cl) versus sodium (Na) diagrams to unambiguously identify the
provenance of obsidian artifacts attributable to Italian outcrops widely exploited during
prehistory, i.e., Lipari, Pantelleria, Palmarola, and Monte Arci. In this further work, we
found that the ratio R = Cl/Na decreases with the age of emplacement (t) of the obsidian
outcrops and can be well described by the inverse law: . Obsidian samples
were analyzed both by electron probe micro-analyzer (EPMA) and by Instrumental Neutron
Activation Analysis (INAA). Radiometric dates have been obtained both from the
literature and through 40Ar/39Ar dating. Data processing confirmed the time evolution of
the Cl/Na ratio through the same equation, indicating that it can be used as an empirical
estimator of the obsidian formation age. A best-fit analysis of the collected data gives
the relation in units of ka. To verify the validity of this relation for
non-Italian obsidians, we applied it to Sierra de Las Navajas (State of Hidalgo, Mexico)
obsidians, estimating an age of 1.75 Ma, in agreement with the upper limit of 1.8–2 Ma
generally accepted for these rocks. We propose that the Cl/Na ratio changes with time because of the differential loss of chlorine and sodium as a consequence of the micro-fracturing
of the obsidian glass after the emplacement. If future tests on different obsidians
can confirm the validity of this approach, a rough estimate of the age of emplacement of
the obsidian outcrops could be derived from their geochemical compositions.PublishedUniversity of California, Berkele
Reprocessing of eXpendable BathyThermograph (XBT) profiles from the Ligurian and Tyrrhenian seas over the time period 1999–2019 with a full metadata upgrade
No full textThe advent of open science and the United Nations Decade of Ocean Science for Sustainable Development are revolutionizing the ocean-data-sharing landscape for an efficient and transparent ocean information and knowledge generation. This blue revolution raised awareness on the importance of metadata and community standards to activate interoperability of the digital assets (data and services) and guarantee that data-driven science preserves provenance, lineage and quality information for its replicability. Historical data are frequently not compliant with these criteria, lacking metadata information that was not retained, crucial at the time of data generation and further ingestion into marine data infrastructures. The present data review is an example attempt to fill this gap through a thorough data reprocessing starting from the original raw data and operational log sheets. The data gathered using XBT (eXpendable BathyThermograph) probes during several monitoring activities in the Tyrrhenian and Ligurian seas between 1999 and 2019 have first been formatted and standardized according to the latest community best practices and all available metadata have been inserted, including calibration information never applied, uncertainty specification and bias correction from Cheng et al. (2014). Secondly, a new automatic quality control (QC) procedure has been developed and a new interpolation scheme applied. The reprocessed (REP) dataset has been compared to the data version, presently available from the SeaDataNet (SDN) data access portal, processed according to the pioneering work of Manzella et al. (2003) conducted in the framework of the European Union Mediterranean Forecasting System Pilot Project (Pinardi et al., 2003). The comparison between REP and SDN datasets has the objective to highlight the main differences derived from the new data processing process. The maximum discrepancy among the REP and SDN data versions always resides within the surface layer (REP profiles are warmer than SDN ones) until 150 m depth generally when the thermocline settles (from June to November). The overall bias and root mean square difference are equal to 0.002 and 0.041 °C, respectively. Such differences are mainly due to the new interpolation technique (Barker and McDougall, 2020) and the application of the calibration correction in the REP dataset. The REP dataset (Reseghetti et al., 2024; https://doi.org/10.13127/rep_xbt_1999_2019.2) is available and accessible through the INGV (Istituto Nazionale di Geofisica e Vulcanologia, Bologna) ERDDAP (Environmental Research Division's Data Access Program) server, which allows for machine-to-machine data access in compliance with the FAIR (findable, accessible, interoperable and reusable) principles (Wilkinson et al., 2016)MACMAP projectPublished5531–5561OSA4: Ambiente marino, fascia costiera ed Oceanografia operativaJCR Journa
Fiber-optic gyroscope for rotational seismic ground motion monitoring of the Campi Flegrei volcanic area
No full textThe real-time monitoring of densely populated areas with high seismic and volcanic risk is of crucial importance for the safety of people and infrastructures. When an earthquake occurs, the Earth surface experiences both translational and rotational motions. The latter are usually not monitored, but their measurement and characterization are essential for a full description of the ground motion. Here we present preliminary observational data of a high-sensitivity rotational sensor based on a 2-km-long fiber-optic Sagnac gyroscope, presently under construction in the middle of the Campi Flegrei Volcanic Area (Pozzuoli, Italy). We have evaluated its performance by analyzing data continuously recorded during an acquisition campaign of five months. The experimental setup was composed of a digital nine-component seismic station equipped with both a rotational sensor and conventional seismic sensors (seismometers, accelerometers, and tiltmeters). During this experiment we detected seismic noise and ground rotations wavefield induced by small to medium local earthquakes (M
D
<3). The prototype gyroscope shows a very promising sensitivity in the range of 5×10−7−8×10−9rad/s/Hz over the frequency bandwidth 5 mHz–50 Hz. Future upgrades and perspectives are discussed.This work was partly funded by the Italian Space
Agency (ASI) in the framework of the HFOG project “High-resolution
interferometric Fiber-Optic Gyroscopes for inertial sensing." Implementation
Agreement n. 2023-1-HH.0 between ASI and CNR-INO. This work was
partly funded by the Next Generation EU program, Italian Recovery and
Resilience Plan (PNRR), Italian Ministry for University and Research (MUR) -
Mission 4, Sustainable Mobility Center CNMS (CN 00000023). This project
has received funding from the European Defense Fund (EDF) under grant
agreement EDF-2021-DIS-RDIS-ADEQAUDE (n◦ 101103417). Funded
by the European Union. Views and opinions expressed are however those of
the author(s) only and do not necessarily reflect those of the European Union.
Neither the European Union nor the granting authority can be held responsible
for them. D.D. partly acknowledges the Next Generation EU program, Italian
Recovery and Resilience Plan (PNRR), Italian Ministry for University and
Research (MUR)-Mission 4, and Sustainable Mobility Center CNMS (CN
00000023).Published4226-4233OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Orogen-parallel discontinuity of the Apennines subduction zone in Southern Italy as seen from mantle wedge seismic structure
No full textWe investigate the seismic structure of the mantle wedge of the Apennines subduction zone (Central Mediterranean)
using teleseismic receiver function (RF). We inverted RF for both isotropic and anisotropic properties of
the mantle wedge, from below the overriding Moho to the “plate boundary”, i.e. the interface that separate the
slab from the mantle wedge. Given the distribution of the seismic network, we are able to map out the change in
the elastic properties at the transition between southern apennines and the Calabrian arc, given by the change in
the subduction style (i.e from the subduction of continental materials to oceanic plate). We found that the
anisotropy in the mantle wedge is similar between all seismic stations, generally highly anisotropic (> 10%),
with a direction of the symmetry axis that rotates clockwise from North to South, following the Calabrian arc
geometry and likely indicating the mantle flow driven by the slab retreat. The elastic properties of the subducted
crust are more heterogeneous. To the North, the subducted crust shows a highly anisotropic (> 10%) behavior,
and it occurs at larger depth (around 70 km depth), where to the South anisotropy is less intense (around 7%)
and the subducted crust is shallower (around 60 km depth). These results point out a change in the subduction
style that can be given by either a change in the metamorphic phase (more evolved blueschist facies stage to the
North, initial greenschist facies stage to the South) or a different origin for the subducted materials (continental
to the North and oceanic to the South). The differences in the anisotropic behavior of the subducted crust are
reflected in the topography of the plate boundary, which becomes shallower from North to South, suggesting the
existence of either a step in the slab topography or a more gentle ramp.Published102004OST1 Alla ricerca dei Motori GeodinamiciJCR Journa
Intensity Prediction Equations Based on the Environmental Seismic Intensity (ESI-07) Scale: Application to Normal Fault Earthquakes
No full textEarthquake environmental effects may significantly contribute to the damage caused by seismic events; similar to ground motion, the environmental effects are globally stronger in the vicinity and decrease moving away from the epicenter or seismogenic source. To date, a single intensity prediction equation (IPE) has been proposed in the Italian Apennines for intensity scale dealings with environmental effects: the Environmental Seismic Intensity (ESI-07). Here, we evaluate the sensitivity of the IPE with respect to input data and methodological choices and we propose IPEs with global validity for crustal normal faults. We show the strong influence of input data on the obtained attenuation investigating the 1980 Irpinia–Basilicata (Southern Italy) earthquake. We exploit a dataset of 26 earthquakes to build an IPE considering the epicentral distance. We also propose an IPE considering the distance from the fault rupture, which is derived from a dataset of 10 earthquakes. The proposed equations are valid for normal faults up to 40 km from the epicenter/fault and may flank other models predicting ground motion or damage to the built environment. Our work thus contributes to the use of the ESI-07 scale for hazard purposes.Published8048JCR Journa
The effects of the May 2024 Mother’s Day superstorm over the Mediterranean sector: from data to public communication
No full textOn 8 May 2024, the solar active region AR13664 started releasing a series of intense solar flares. Those of class X released between 9 and 11 May 2024 gave rise to a chain of fast Coronal Mass Ejections (CMEs) that proved to be geoeffective. The Storm Sudden Commencement (SSC) of the resulting geomagnetic storm was registered on 10 May 2024 and it is, to date, the strongest event since November 2003. The May 2024 storm, named hereafter Mother’s Day storm, peaked with a Dst of –412 nT and stands out as a “standard candle” storm affecting modern era technologies prone to Space Weather threats. Moreover, the recovery phase exhibited almost no substorm signatures, making the Mother’s Day storm as a perfect storm example. Despite the plethora of notable near Earth environment modifications that are still under investigation, in this paper we concentrate on the Space Weather effects over the Mediterranean sector, with a focus on Italy. In fact, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) manages a dense network of GNSS receivers (including scintillation receivers), ionosondes and magnetometers in the Mediterranean area, which facilitated for a detailed characterization of the modifications induced by the storm. Concerning the geomagnetic field, observatories located in Italy recorded a SSC with a rise time of only 3 minutes and a maximum variation of around 600 nT. The most notable ionospheric effect following the arrival of the disturbance was a significant decrease in plasma density on 11 May, resulting in a pronounced negative ionospheric storm registered on both the critical F2-layer frequency (foF2) and the Total Electron Content (TEC). Another negative effect was recorded on 13 May, while no signatures of composition changes and, specifically, to a decrease of the [O]/[N ] ratio. The IRI UP IONORING 2 data-assimilation procedure, recently developed to nowcast foF2 over Italy, proved to be quite reliable during this extreme event, being characterised just by an overestimation during the main phase of the storm, when the electron density and the height of the F region decreased and increased, respectively. Relevant outcomes of the work relate to the Rate Of TEC change Index (ROTI), which shows unusually high spatially distributed values on the nights of 10 and 11 May. The ROTI enhancements on 10 May might be linked to Stable Auroral Red (SAR) arcs and an equatorward displacement of the main ionospheric trough. Instead, the ROTI enhancements on 11 May might be triggered by a joint action of low-latitude plasma pushed poleward by the pre-reversal enhancement (PRE) in the post-sunset hours and wave-like perturbations propagating from the North. Furthermore, the storm generated immediate attention of the general public to Space Weather effects, including mid-latitude visible phenomena like SAR arcs. This paper outlines the report of the Space Weather Monitoring Group (SWMG) of the INGV Environment Department and its effort to disseminate information about this exceptional event.PublishedPA218OSA3: Climatologia e meteorologia spazialeJCR Journa
Correlated 0.01–40 Hz seismic and Newtonian noise and its impact on future gravitational-wave detectors
No full textWe report correlations in underground seismic measurements with horizontal separations of several hundreds of meters to a few kilometers in the frequency range 0.01 to 40 Hz. These seismic correlations could threaten science goals of planned interferometric gravitational-wave detectors such as the Einstein Telescope as well as atom interferometers such as MIGA and ELGAR. We use seismic measurements from four different sites, i.e., the former Homestake mine (USA) as well as two candidate sites for the Einstein Telescope, Sos Enattos (IT), and Euregio Maas-Rhein (NL-BE-DE) and the site housing the MIGA detector, LSBB (FR). At all sites, we observe significant coherence for at least 50% of the time in the majority of the frequency region of interest. Based on the observed correlations in the seismic fields, we predict levels of correlated Newtonian noise from body waves. We project the effect of correlated Newtonian noise from body waves on the capabilities of the triangular design of the Einstein Telescope to observe an isotropic gravitational-wave background (GWB) and find that, even in case of the most quiet site, its sensitivity will be affected up to ∼20 Hz. The resolvable amplitude of a GWB signal with a negatively sloped power-law behavior would be reduced by several orders of magnitude. However, the resolvability of a power-law signal with a slope of e.g., α=0 (α=2/3) would be more moderately affected by a factor ∼6–9(∼3–4) in case of a low-noise environment. Furthermore, we bolster confidence in our results by showing that transient noise features have a limited impact on the presented results.Published102002OST5 Verso un nuovo MonitoraggioJCR Journa
Long-term analysis of microseism during extreme weather events: Medicanes and common storms in the Mediterranean Sea
No full textIn this work, we analyze 12 meteorological events that occurred in the Mediterranean Sea during the period November 2011-November 2021 from a seismic point of view. In particular, we consider 8 Medicanes and 4 more common storms. Each of these events, in spite of the marked differences between them, caused heavy rainfall, strong wind gusts and violent storm surge with significant wave heights usually >3 m. We deal with the relationships between these meteorological events and the features of microseism (the most continuous and widespread seismic signal on Earth) in terms of spectral content, space-time variation of the amplitude and source locations tracked employing two different methods (amplitude decay-based grid search and array techniques). By comparing the positions of the microseism sources with the areas of significant storm surges, we observe that the microseism locations align with the actual locations of the storm surges for 10 out of 12 events analyzed (two Medicanes present very low intensity in terms of meteorological parameters and the microseism amplitude does not show significant variations during these two events). We also perform two analyses that allowed us to obtain both the seismic signature of these events, by using a method that exploits the coherence of continuous seismic noise, and their strength from a seismic point of view, called Microseism Reduced Amplitude. In addition, by integrating the results obtained from these two methods, we are able to "seismically" distinguish Medicanes and common storms. Consequently, we demonstrate the possibility of creating a novel monitoring system for Mediterranean meteorological events by incorporating microseism information alongside with other commonly employed techniques for studying meteorological phenomena. The integration of microseism with the data provided by routinely used techniques in sea state monitoring (e.g., wave buoy and HF radar) has the potential to offer valuable insights into the examination of historical extreme weather events within the context of climate change.Published169989OSA4: Ambiente marino, fascia costiera ed Oceanografia operativaJCR Journa