OA Earth-prints Repository
Not a member yet
16457 research outputs found
Sort by
2021–2023 Unrest and Geodetic Observations at Askja Volcano, Iceland
No full textUnrest began in July 2021 at Askja volcano in the Northern Volcanic Zone (NVZ) of Iceland. Its
most recent eruption, in 1961, was predominantly effusive and produced ∼0.1 km3 lava field. The last plinian
eruption at Askja occurred in 1875. Geodetic measurements between 1983 and 2021 detail subsidence of Askja,
decaying in an exponential manner. At the end of July 2021, inflation was detected at Askja volcano, from
GNSS observations and Sentinel‐1 interferograms. The inflationary episode can be divided into two periods
from the onset of inflation until September 2023. An initial period until 20 September 2021 when geodetic
models suggest transfer of magma (or magmatic fluids) from within the shallowest part of the magmatic system
(comprising an inflating and deflating source), potentially involving silicic magma. A following period when
one source of pressure increase at shallow depth can explain the observations.Publishede2023GL106730OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Applications of Ground-Based Infrared Cameras for Remote Sensing of Volcanic Plumes
No full textGround-based infrared cameras can be used effectively and safely to provide quantitative information about small to moderate-sized volcanic eruptions. This study describes an infrared camera that has been used to measure emissions from the Mt. Etna and Stromboli (Sicily, Italy) volcanoes. The camera provides calibrated brightness temperature images in a broadband (8–14 µm) channel that is used to determine height, plume ascent rate and volcanic cloud/plume temperature and emissivity at temporal sampling rates of up to 1 Hz. The camera can be operated in the field using a portable battery and includes a microprocessor, data storage and WiFi. The processing and analyses of the data are described with examples from the field experiments. The updraft speeds of the small eruptions at Stromboli are found to decay with a timescale of ∼10 min and the volcanic plumes reach thermal equilibrium within ∼2 min. A strong eruption of Mt. Etna on 1 April 2021 was found to reach ∼9 km, with ascent speeds of 10–20 ms−1. The plume, mostly composed of the gases CO2, water vapour and SO2, became bent over by the prevailing winds at high levels, demonstrating the need for multiple cameras to accurately infer plume heights.Published82OSV3: Sviluppo di nuovi sistemi osservazionali e di analisi ad alta sensibilitàJCR Journa
CFTIlandslides, Italian database of historical earthquake-induced landslides
No full textKnowing the location, the extent and the characteristics of any earthquake-induced environmental phenomenon is becoming an increasingly pressing need for civil protection agencies and local administrations. In particular, earthquake-triggered landslides are known for being among the most important sources of secondary hazard, as they may cause significant losses and may delay rescue operations across large areas. The combination of the relatively frequent seismic release with a very high landslide susceptibility makes the Italian territory especially prone to the occurrence of earthquake-induced landslides. The CFTIlandslides dataset features over 1,000 landslides triggered by historical Italian earthquakes (up to 1997). The landslides effects are subdivided into classes based on location accuracy and type of movement. Knowing the distribution of the past earthquake-induced landslides provides the input information for assessing the related hazard. This dataset is addressed to a large audience of potential users, including researchers and scholars, administrators and technicians belonging to local institutions, and civil protection authorities.Published834OST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Ionosphere Monitoring with Remote Sensing Vol II
No full textUnderstanding the processes occurring in the Earth’s ionosphere is of utmost importance to characterize several phenomena relevant for Space Weather. In fact, the ionospheric plasma promptly reacts to variations in magnetic and electric fields and, thus, is particularly sensitive to different processes on a wide range of spatial and temporal scales. These variations may substantially affect, for instance, the physical properties of the ionosphere, its energetic balance, and the propagation of electromagnetic signals throughout the ionospheric layers.
Thanks to the increased volume of high-quality data, these features can now be reliably investigated due to the joint effort of remote sensing and in situ facilities, such as ionosondes, radars, satellites, and GNSS receivers. This Special Issue aims to encourage advances in our knowledge of the ionosphere through the use of complementary data with different origins and their comparison with models.
This Special Issue is the second edition of Ionosphere Monitoring with Remote Sensing Based on previous research results, contributions that address but are not restricted to the following topics are welcome:
The impact of sunlit, solar and geomagnetic activity on the ionosphere at all latitudes;
The impact of ionospheric variations on technology;
Improvements and new constraints of ionospheric models through new observations, analyses and techniques;
Investigating the magnetosphere–ionosphere coupling through different multi-instrumental approaches;
New instruments, missions and tools to monitor the ionosphere.Published2762OSA3: Climatologia e meteorologia spazialeJCR Journa
Calibration HPGe detector using IAEA-U source for CBRNe
No full textDetecting and preventing the illicit movement of radioactive materials within a country is crucial, requiring the identification of radiologic anomalies against the normal radiation background. High-purity germanium (HPGe) detectors, known for their precision and sensitivity, have become popular for analyzing radioactive materials in CBRNe scenarios. This study focused on calibrating an HPGe detector for CBRNe applications, using gamma-ray spectra from an IAEA-U reference source. Energy calibration involved identifying peaks in the spectra and creating a calibration curve for energy and channel number data. Efficiency calibration, determined using the known activity of the source, revealed a linear relationship between energy and detector response. Over four years, systematic efficiency calibrations showed a deviation of only 3% well below the recommended limit of 5%. These findings underscore the reliability of the system as a reference spectrometry method for accurate detection of radioactive materials.Published654OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorioJCR Journa
Complex lava tube networks developed within the 1792–93 lava flow field on Mount Etna (Italy): insights for hazard assessment
No full textLava tubes are powerful heat insulators, allowing lava to practically keep the initial temperature and travel longer distances than when freely flowing on the ground surface. It is thus extremely important to recognize how, when and where these structures form within a lava flow field for hazard assessment purposes, in order to plan possible interventions should a lava flow approach inhabited areas. Often being formed within thick and complex lava flow fields, lava tubes are difficult to detect, study and explore. In this study, we analyse the 1792–93 Etna lava flow field emplaced on a steep slope (>4°) which comprises several lava tubes located at different distances from the eruptive fissure, at different levels within the lava flow field, and showing various inner morphologies, with peculiar inner features related to their maturity and eruptive history. Our aim is to verify whether it is possible to connect the underground features with features observed on the lava flow surface in order to reconstruct the extension of the tube network and unravel the genetic processes. Our results show that, in the studied lava flow field, a clear correspondence is possible between shallow tubes emplaced late during the lava flow field growth and surface textures. In addition, vertical and horizontal tube capture is very widespread, and might be the primary process for lava tube persistence and long life. Our results might be applicable to other lava tubes on Earth and other rocky planets.This paper was funded by the project “Understanding lava tube formation and preservation (TUBES)” PRIN2022PNRR, cod. P2022N5C3 -CUPD53D23022910001 European Union-Next generation EU. It also benefitted from funds of the project FIRST - ForecastIng eRuptive activity at Stromboli volcano (Delibera n. 144/2020; Scientific Responsibility: S. C.) INGV-Volcano Department, 2019.Published1448187OSV1: Verso la previsione dei fenomeni vulcanici pericolosiJCR Journa
Where will the next flank eruption at Etna occur? An updated spatial probabilistic assessment
No full textThe assessment of the spatial probability of future vent opening is one of the key factors in quantifying volcanic hazard, especially for active volcanoes where eruptions can occur at different locations and altitudes over distributed areas. Mount Etna (Italy), one of the most active volcanoes in the world, exhibits such variability, and its flank eruptions can harm people, properties and services over the volcano’s slopes. In this paper, we quantify the spatial probability of
future vent opening for Etna’s flank eruptions, adopting a kernel analysis and testing different functions (exponential, Cauchy, uniform and Gaussian). Starting from the assumption that the location of past fissures is indicative of where future events will occur, we consider the flank eruptions of the last 4000 years, thus accounting for a much longer and complete record than in previous studies. The large dataset of eruptive fissures enables splitting the data into training and testing subsets. This allows selecting the best kernel model, testing the completeness of the fissure dataset and investigating a possible migration through time in fissure location. The results show that neither under-recording nor possible migration over time significantly affects the informative value of previous flank fissures in forecasting the location of future ones. The resulting map highlights that the most likely opening area follows a northeast-to-south trend, corresponding to the location of the most active rifts. It also shows that the southern flank of the volcano, which is the most urbanized one, sits downhill of the largest cumulated probability area for flank eruption. We also run sensitivity analyses to test the effect of (i) restricting the data to the most recent 400 years and (ii) including the information on the stress induced on the mapped fissures by sources of deformation proposed in the literature for recent eruptions of Etna. The sensitivity analyses confirm the main features of the proposed map and add information on the epistemic uncertainty attached to it.Published4431–4455JCR Journa
Characteristics of strong ground motions and structural damage patterns from the February 6th, 2023 Kahramanmaraş earthquakes, Türkiye
No full textOn February 6th, 2023, two severe earthquakes struck southeastern Türkiye near the Syrian border. The first earthquake, Mw7.8, occurred at 04:17 local time in the East Anatolian Fault Zone near the city of Gaziantep. The second earthquake, Mw7.5, occurred approximately 9 h later at 13:24 local time near Elbistan County, in Kahramanmaraş province. These seismic events ruptured multiple segments of the East Anatolian Fault Zone (EAFZ), with rupture lengths exceeding 300 km, and deformation exceeding 5 m on both sides of the faults. In this study, we aim to analyze characteristics of the strong ground motion induced by the mainshocks, focusing on ground motion intensity measures such as the peak ground acceleration (PGA), the peak ground velocity (PGV), and the pseudo-acceleration response spectra (PSA). The first earthquake produced extremely high PGA values in both horizontal (> 2 g) and vertical (> 1 g) components. At near field distances, large PGVs are measured (> 180 cm/s) with more than 30 impulsive motions which may indicate source-related effects. Large spectral demands are also recorded for both earthquakes, partially underestimated by Ground Motion Models (GMMs), especially in the near-field. Specifically, we compare the PSA for horizontal directions with the design spectra provided by both the new and previous Turkish building codes. We also present building and ground damage observations that provide insights into the observed ground motions in the heavily damaged areas.In pressOST2 Deformazione e Hazard sismico e da maremotoJCR Journa
Geophysical downhole logging analysis within the shallow-depth ICDP STAR drilling project (central Italy)
No full textAbstract. The International Continental Scientific Drilling Program (ICDP) STAR (A Strainmeter Array Along the Alto Tiberina Fault System) drilling project aims to study the seismic and aseismic fault slip behavior of the active low-angle Alto Tiberina normal fault (ATF) in the northern Apennines, central Italy, by drilling and instrumenting six shallow boreholes (maximum depth 160 m) with seismometers and strainmeters. During the STAR fieldwork, a geophysical downhole logging campaign was carried out to define the optimal target depth for instrument deployment and formation rock characterization. In particular, the main objectives of this study were to define in situ physical properties of the rocks and the tectonic discontinuity geometry along the boreholes. The downhole logging data provide new findings and knowledge, especially with regards to physical properties such as resistivity and gamma-ray and wave velocity. The collected parameters were compared to the results of literature data collected in similar lithologies, as well as with the results of logging performed in deeper wells drilled for commercial purposes. The physical properties of the Mesozoic–early Tertiary calcareous formations show low gamma-ray values and high compressional (Vp) and shear wave (Vs) velocities (up to 5.3 and 2.9 km s−1, respectively), whereas the overlying clay-rich Late Tertiary formations exhibit high gamma-ray and low resistivity values as well as relatively low Vp and Vs values (up to 3.5 and 2.0 km s−1, respectively). The results obtained from the analysis of the orientations of the tectonic structures, measured along the six boreholes, show good agreement with the orientations of the present-day extensional stress field, which is NE–SW-oriented. Our study allowed us to bridge the gap between the physical properties obtained from literature data and those obtained from the deep well measurements, representing a possible case history for future projects. These new outcomes represent an almost unexplored window of data and will contribute to the advancement of knowledge of the physical properties of the rocks at shallow depths, which are typically overlooked.This research has been supported by the International
Continental Scientific Drilling Program (ICDP-2018/05)
and the European Research Council (ERC; grant agreement
no. 835012, TECTONIC). In addition, this work would not have
been possible without the contribution of the Istituto Nazionale di
Geofisica e Vulcanologia.Published1385–1406JCR Journa
MUDA: dynamic geophysical and geochemical MUltiparametric DAtabase
No full textIn this paper, the new dynamic geophysical and geochemical MUltiparametric DAtabase (MUDA) is presented. MUDA is a new infrastructure of the National Institute of Geophysics and Volcanology (INGV), published online in December 2023, with the aim of archiving and disseminating multiparametric data collected by multidisciplinary monitoring networks. MUDA is a MySQL relational database with a web interface developed in PHP, aimed at investigating possible correlations between seismic phenomena and variations in endogenous and environmental parameters in quasi real time. At present, MUDA collects data from different types of sensors such as hydrogeochemical probes for physical–chemical parameters in waters, meteorological stations, detectors of air radon concentration, diffusive flux of carbon dioxide (CO2) and seismometers belonging both to the National Seismic Network of INGV and to temporary networks installed in the framework of multidisciplinary research projects. MUDA publishes data daily, updated to the previous day, and offers the chance to view and download multiparametric time series selected for different time periods. The resultant dataset provides broad perspectives in the framework of future high-frequency and continuous multiparametric monitoring as a starting point to identify possible seismic precursors for short-term earthquake forecasting. MUDA can be accessed at https://doi.org/10.13127/muda (Massa et al., 2023).
Published4843–4867OST3 Vicino alla fagliaJCR Journa