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The contribution of Geomatics to increase safety and security in ports
No full textIn this paper, the advantages achievable from the use of two prototype systems that are being developed to increase safety and security in ports are shown. Both systems start by monitoring environmental parameters in harbors, and then process data acquired. The first system has been conceived to be helpful to port communities (port authorities, pilots) to optimize harbor waterside management (ship’s navigation and cargo, dock performances, boat moorings, refloating of stranded ships, water quality control). By monitoring and processing sea level and atmospheric pressure in port areas, it can help port communities, e.g., to choose the best time when a ship with a certain draft can enter or leave a harbor, or to plan the best route inside the basin for that vessel (port safety). The second system, instead, has been designed for port protection purposes: by monitoring and processing the Earth’s magnetic field below the sea surface in harbors (where the natural field is disturbed by a high artificial component), it is able to detect the possible presence of intruders (e.g., divers) swimming underwater in prohibited areas (port security). Here, the results of monitoring and processing activities of the two systems performed in Livorno and La Spezia harbors are shown (Italy). The processing procedures and the graphical interfaces of the systems are based on applications under development by the research team the author belongs to, by using C# and C++ languages; Matlab environment has been employed for simulations.Published647–6581A. Geomagnetismo e Paleomagnetismo3A. Geofisica marina e osservazioni multiparametriche a fondo mare4A. Oceanografia e clima7SR AMBIENTE – Servizi e ricerca per la societàJCR Journa
Impact of SO2 Flux Estimation in the Modeling of the Plume of Mount Etna Christmas 2018 Eruption and Comparison against Multiple Satellite Sensors
No full textIn this study, we focus on the eruption of Mount Etna on Christmas 2018, which emitted great amounts of SO2
from 24th to 30th December into the free troposphere. Simulations based on two different estimations of SO2
emission fluxes are conducted with the chemistry-transport model MOCAGE in order to study the impact of these estimations on the volcanic plume modeling. The two flux emissions used are retrieved (1) from the ground-based network FLAME, located on the flank of the volcano, and (2) from the spaceborne instrument SEVIRI onboard the geostationary satellite MSG. Multiple spaceborne observations, in the infrared and ultraviolet bands, are used to evaluate the model results. Overall, the model results match well with the plume location over the period of the eruption showing the good transport of the volcanic plume by the model, which is linked to the use of a realistic estimation of the altitude of injection of the emissions. However, there are some discrepancies in the plume concentrations of SO2
between the two simulations, which are due to the differences between the two emission flux estimations used that are large on some of the days. These differences are linked to uncertainties in the retrieval methods and observations used to derive SO2
volcanic fluxes. We find that the uncertainties in the satellite-retrieved column of SO2
used for the evaluation of the simulations, linked to the instrument sensitivity and/or the retrieval algorithm, are sometimes nearly as large as the differences between the two simulations. This shows a limitation of the use of satellite retrievals of SO2
concentrations to quantitatively validate modeled volcanic plumes. In the paper, we also discuss approaches to improve the simulation of SO2
concentrations in volcanic plumes through model improvements and also via more advanced methods to more effectively use satellite-derived products.Published7585V. Processi eruttivi e post-eruttiviJCR Journa
Ionospheric equivalent slab thickness ingestion into the NeQuick model
No full textThe ionospheric equivalent slab thickness (), defined as the ratio of the vertical total electron
content (vTEC) to the ionospheric F2‑layer electron density maximum (NmF2), is a parameter
providing useful information on the shape of the vertical electron density profile. However, the
use of this information is of difficult practical application in empirical ionosphere models, such
as the NeQuick, because by design they do not explicitly include as a modelling parameter. In
this work, we investigated the opportunity of using measured values to improve the empirical
modelling of the ionosphere vertical electron density profile by NeQuick. Measured values were
obtained through NmF2 observations and vTEC measurements obtained between 2001 and 2019
by an ionosonde and a ground-based GNSS receiver, respectively, co‑located at Rome ionospheric
station (41.8° N, 12.5° E; Italy). NeQuick was obtained as the ratio between modelled NmF2 and
vTEC values, the latter calculated by integration of the vertical profile. As a first step, values
modelled by NeQuick were compared with corresponding values measured at Rome station to
highlight diurnal, seasonal, and solar activity differences. Then, measured values were ingested
in NeQuick through a three-parameter assimilation procedure which first assimilates F2‑layer peak
characteristics to constrain the F2‑layer anchor point, and then assimilates vTEC to optimize the
F2‑layer shape through the NeQuick F2‑layer thickness parameter, namely B2bot. The assimilation
procedure provides information on how the NeQuick B2bot has to be modified to match measured
values, and then on how the shape of the F2‑layer profile has to be changed accordingly. Our results
highlight that, in many cases, the NeQuick B2bot has to be increased to match observations, which
has implications on the modelling of the NeQuick bottomside and topside effective scale heights.PublishedPA528OSA3: Climatologia e meteorologia spazialeJCR Journa
Mass balance of the Greenland and Antarctic ice sheets from 1992 to 2020
No full textIce losses from the Greenland and Antarctic ice sheets have accelerated since the 1990s, accounting for a significant increase in the global mean sea level. Here, we present a new 29-year record of ice sheet mass balance from 1992 to 2020 from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE). We compare and combine 50 independent estimates of ice sheet mass balance derived from satellite observations of temporal changes in ice sheet flow, in ice sheet volume, and in Earth's gravity field. Between 1992 and 2020, the ice sheets contributed 21.0±1.9 mm to global mean sea level, with the rate of mass loss rising from 105 Gt yr−1 between 1992 and 1996 to 372 Gt yr−1 between 2016 and 2020. In Greenland, the rate of mass loss is 169±9 Gt yr−1 between 1992 and 2020, but there are large inter-annual variations in mass balance, with mass loss ranging from 86 Gt yr−1 in 2017 to 444 Gt yr−1 in 2019 due to large variability in surface mass balance. In Antarctica, ice losses continue to be dominated by mass loss from West Antarctica (82±9 Gt yr−1) and, to a lesser extent, from the Antarctic Peninsula (13±5 Gt yr−1). East Antarctica remains close to a state of balance, with a small gain of 3±15 Gt yr−1, but is the most uncertain component of Antarctica's mass balance. The dataset is publicly available at https://doi.org/10.5285/77B64C55-7166-4A06-9DEF-2E400398E452 (IMBIE Team, 2021).Published1597–16165A. Ricerche polari e paleoclimaJCR Journa
The structure of sedimentary basins of Antarctica and a new three-layer sediment model
No full textWe use geophysical data together with a recent subglacial bedrock map (BEDMACHINE model) to obtain and investigate a new three-layer sediment model for Antarctica that locally improves the global sediment model. We provide a combined, continuous, sediment model for Antarctica and surrounding oceans by joining such improved continental sedimentary model with an existing global one (GlobSed). Our results reveal large differences between sedimentary basins for Antarctica due to their age and origin. The maximum thickness of sediments is reached under Filchner-Ronne Ice Shelf and off the Weddell Sea coast (10–12 km); further offshore, towards the ocean, the thickness of sediments drops to 4–5 km. We divide the sediment cover into three layers to distinguish material with different velocities. The lower sediment layer (deeper than 7 km) with high P-wave velocities (4.0–4.9 km/s) is found only for Lambert Rift and Filchner-Ronne basin. The middle layer (2–7 km) has large variations for different sedimentary basins: 3.5–3.7 km/s for Lambert Basin; 4.0–4.3 km/s for Ross, Byrd and Bentley basins; 3.3–4.0 km/s for Filchner-Ronne Basin. The upper sediment layer (0–2 km) has large velocity variations, from 2.0 km/s for Ross and Lambert basins (young sediments) to 4.7 km/s for Dronning Maud Land basins. We suggest that P-wave velocities larger than 4 km/s represent old, compacted sediments which belong to the Beacon Supergroup; about 3 km/s refer to Mesozoic (rifted?) sediments; and less than 3 km/s relate to young Cenozoic sediments. According to this criterion, Dronning Maud Land, Bentley and Byrd basins belong to the Beacon Supergroup, while more complex and thicker Ross, Lambert and Filchner-Ronne basins contain sediments from Beacon Supergroup in the middle or lower layer, respectively. Other sedimentary basins with more moderate velocities possibly belong to the East Antarctic Rift System which formed later during Gondwana breakup.Published229662OST1 Alla ricerca dei Motori GeodinamiciJCR Journa
Groundwater recharge distribution due to snow cover in shortage conditions (2019–22) on the Gran Sasso carbonate aquifer (Central Italy)
No full textAquifer recharge by the snowpack is relevant to be assessed to evaluate groundwater availability in mountainous karst regions.
The recharge due to snowpack in the Gran Sasso aquifer has previously been estimated through an empirical approach using
elevation gradients. To validate and quantify the coverage and persistence of the snowpack over time through an objective
method, satellite images have been analysed. The Campo Imperatore plain, the endorheic basin acting as a preferential
recharge area of the aquifer, plays an important role, both for the snow cover and also for the infiltration and recharge
of springs. The identification of recharge areas has been validated by the stable isotope approach with the assessment of
computed isotope recharge elevation based on the values and oscillations of the δ18O isotope recorded at the springs. The
main findings confirm the high infiltration rate of Campo Imperatore plain and its direct influence on snow contribution to
aquifer recharge. The extension of snow coverage out of this plain has a minor influence to recharge, highlighting that the
main drivers for infiltration rate are fractured networks and karstic forms more than snow coverage on carbonate outcrops.Published206JCR Journa
Present-Day Surface Deformation in North-East Italy Using InSAR and GNSS Data
No full textGeodetic data can detect and estimate deformation signals and rates due to natural and anthropogenic phenomena. In the present study, we focus on northeastern Italy, an area characterized by ~1.5–3 mm/yr of convergence rates due to the collision of Adria-Eurasia plates and active subsidence along the coasts. To define the rates and trends of tectonic and subsidence signals, we use a Multi-Temporal InSAR (MT-InSAR) approach called the Stanford Method for Persistent Scatterers (StaMPS), which is based on the detection of coherent and temporally stable pixels in a stack of single-master differential interferograms. We use Sentinel-1 SAR images along ascending and descending orbits spanning the 2015–2019 temporal interval as inputs for Persistent Scatterers InSAR (PSI) processing. We apply spatial-temporal filters and post-processing steps to reduce unrealistic results. Finally, we calibrate InSAR measurements using GNSS velocities derived from permanent stations available in the study area. Our results consist of mean ground velocity maps showing the displacement rates along the radar Line-Of-Sight for each satellite track, from which we estimate the east–west and vertical velocity components. Our results provide a detailed and original view of active vertical and horizontal displacement rates over the whole region, allowing the detection of spatial velocity gradients, which are particularly relevant to a better understanding of the seismogenic potential of the area. As regards the subsidence along the coasts, our measurements confirm the correlation between subsidence and the geological setting of the study area, with rates of ~2–4 mm/yr between the Venezia and Marano lagoons, and lower than 1 mm/yr near Grado.Published1704OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
The EPOS multi-disciplinary Data Portal for integrated access to solid Earth science datasets
No full textThe European Plate Observing System (EPOS) is a long-term initiative aimed at integrating research infrastructures for solid Earth science in Europe. EPOS provides a sustainable, multidisciplinary user-oriented platform - the EPOS Data Portal - that facilitates data integration, access, use, and re-use, while adhering to the FAIR principles. The paper describes the key governance, community building, and technical aspects for achieving multidisciplinary data integration through the portal. It also outlines the key portal features for aggregating approximately 250 data sources from more than ten different scientific communities. The main architectural concepts underpinning the portal, namely the rich-metadata, the service-driven data provision, and the usage of semantics, are outlined. The paper discusses the challenges encountered during the creation of the portal, describes the community engagement process, and highlights the benefits to the scientific community and society. Future work includes expanding portal functionalities to include data analysis, processing, and visualization and releasing the portal as an open-source software package.Published784OST5 Verso un nuovo MonitoraggioJCR Journa
Geochemical characteristics of natural springs within the Lenglongling fault zone related to the Menyuan Ms 6.9 earthquake on January 8, 2022, NW China
No full textGeofluids from natural springs connect with the crust and/or mantle in many cases, and their geochemical
anomalies could be significant for the study on faults activity and even earthquakes. Several natural springs are
distributed along the Lenglongling fault zone (LLLFZ) in the northeastern margin of the Tibetan Plateau, where
the Ms 6.9 Menyuan earthquake occurred on January 8th, 2022. Based on chemical and isotopic compositions
(δD, δ18O, δ13C, and 3He/4He) of water and gas samples, the origin of geofluids and their potential correlation
with fault activity even including earthquakes are preliminarily assessed in this paper. The δ13CCO2 values and
3He/4He ratios showed that the gas originating from the crust was associated with the metamorphism of carbonate
rocks, whereas the δ18O and δD values of water samples indicated that the natural springs were predominantly
infiltrated with precipitations from local mountains ranging 3.7 - 5.5 km in height. Obvious changes
of Ca2+ and HCO3 concentrations in SZK spring waters in the surface rupture zones were observed in a short
period (about three months) after the main shock, in contrast to those of the GSK springs far from the surface
rupture zones. Such variations might be correlated with the stress increase prior to the 2022 Menyuan Ms 6.9
earthquake. The mechanical fracturing of surrounding limestone rocks during the slipping movement of LLLF
could facilitate the water-rock interactions. Compared to three-month observations after the main shock, relatively
higher concentrations of HCO3 and heavier δ18OH2O values of the LHG springs were also observed in the
short-term period. The shallow stored formation water might be squeezed along the cracks and rose to the surface
during earthquake tremors, causing a sandblasting water phenomenon.Published105767JCR Journa
Slope-break Collisions: Comment on “Insight Into Granular Flow Dynamics Relying on Basal Stress Measurements: From Experimental Flume Tests” by K. Li et al.
No full textNumerical simulations show that the positive correlation observed in laboratory experiments by Li et al. (2022) between an increase of grain size and particle agitation, on the one hand, and an increase of granular flow mobility, on the other hand, is not a valid cause-and-effect relationship. In other words, their mobility differential is not caused by a different energy dissipation rate that results from a different grain size content. Instead, the flows stop because of a head-on collision with the horizontal flume at the bottom of a steep 40º incline. Essentially, the slope-break jams the granular movement. Indeed, a combination of laboratory experiments and numerical simulations demonstrated that the mobility of unhindered dense granular flows increases as grain size and clast agitation decrease. Consequently, there is no evidence that the high mobility of large natural rock avalanches is due to an increase of particle agitation.Publishede2022JB0247996V. Pericolosità vulcanica e contributi alla stima del rischioJCR Journa