ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    On the Source Parameters and Genesis of the 2017, Mw 4 Montesano Earthquake in the Outer Border of the Val d’Agri Oilfield (Italy) (2021)
    MDPI
    Details
    Publication Date: 2021-03-24
    Description: On October 27, 2017, an Mw 4 earthquake occurred close to the municipality of Montesano sulla Marcellana, less than 10 km external to the concession of the largest European onshore hydrocarbon reservoir—the Val d’Agri oilfield (Southern Italy). Being a weak event located outside the extended monitoring domain of the industrial concession, the relevance of this earthquake and the possible links with the hydrocarbon exploitation were not extensively discussed. Actually, the analysis of shallow seismic events close to subsurface exploitation domains plays a significant role in the definition of key parameters in order to discriminate between natural, triggered, and induced seismicity, especially in tectonically active regions. The study of weak-to-moderate earthquakes can improve the characterization of the potentially destructive seismic hazard of this particular area, already struck by M 〉 6.5 episodes in the past. In this work, we analyze the source parameters of this Mw 4 earthquake by applying advanced seismological techniques to estimate the uncertainties derived from the moment tensor inversion and identify plausible directivity effects. The moment tensor is dominated by a NW–SE oriented normal faulting with a centroid depth of 14 km. A single ML 2.1 aftershock was recorded and used as the empirical Green’s function to calculate the apparent source time function for the mainshock. Apparent durations (in the range 0.11–0.21 s, obtained from S-waves) define an azimuthal pattern, which reveals an asymmetric bilateral rupture with 70% of the rupture propagation in the N310°Wdirection, suggesting a rupture plane dipping to the SW. Our results tally with the activation of a deeper fault segment associated with the Eastern Agri Fault System close to the basement as the origin of the Montesano earthquake. Finally, the Coulomb stress rate induced by depletion of the oilfield is calculated to quantify the trigger potential estimated for the Montesano earthquake yielding relatively low probabilities below 10%. Our analyses point toward the conclusion that the Mw 4 event was more likely due to the local natural tectonic stress, rather than induced or triggered by the long-term hydrocarbon extraction in the Val d’Agri oilfield.
    Description: Published
    Description: 617794
    Description: 3T. Fisica dei terremoti e Sorgente Sismica
    Description: JCR Journal
    Keywords: earthquake source ; induced seismicity ; directivity ; triggered earthquake ; Val d’Agri oilfield ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Evaluation of Pre-Earthquake Anomalies of Borehole Strain Network by Using Receiver Operating Characteristic Curve (2021)
    MDPI
    Details
    Publication Date: 2021-05-12
    Description: In order to monitor temporal and spatial crustal activities associated with earthquakes, ground- and satellite-based monitoring systems have been installed in China since the 1990s. In recent years, the correlation between monitoring strain anomalies and local major earthquakes has been verified. In this study, we further evaluate the possibility of strain anomalies containing earthquake precursors by using Receiver Operating Characteristic (ROC) prediction. First, strain network anomalies were extracted in the borehole strain data recorded in Western China during 2010–2017. Then, we proposed a new prediction strategy characterized by the number of network anomalies in an anomaly window, Nano, and the length of alarm window, Talm. We assumed that clusters of network anomalies indicate a probability increase of an impending earthquake, and consequently, the alarm window would be the duration during which a possible earthquake would occur. The Area Under the ROC Curve (AUC) between true predicted rate, tpr, and false alarm rate, fpr, is measured to evaluate the efficiency of the prediction strategies. We found that the optimal strategy of short-term forecasts was established by setting the number of anomalies greater than 7 within 14 days and the alarm window at one day. The results further show the prediction strategy performs significantly better when there are frequent enhanced network anomalies prior to the larger earthquakes surrounding the strain network region. The ROC detection indicates that strain data possibly contain the precursory information associated with major earthquakes and highlights the potential for short-term earthquake forecasting.
    Description: National Natural Science Foundation of China under Grant 41974084 Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, under its observation and Research Program for Prediction of Earthquakes and Volcanic Eruptions.
    Description: Published
    Description: 515
    Description: 7T. Variazioni delle caratteristiche crostali e precursori sismici
    Description: JCR Journal
    Keywords: receiver operating characteristic ; a new prediction strategy ; frequent network anomalies ; prediction efficiency ; short-term earthquake forecasting ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Seismic Coda-Waves Imaging Based on Sensitivity Kernels Calculated Using an Heuristic Approach (2021)
    MDPI
    Details
    Publication Date: 2021-02-02
    Description: Abstract: In this paper we review and discuss the seismic method based on the analysis of seismic coda waves used in the last 10 years by the present authors and/or their co-workers, to produce separate images of intrinsic- and scattering attenuation in zones of peculiar geological interest (mainly volcanoes). Such separate attenuation images are considered by the scientific community as complementary to those from ordinary velocity-tomography and useful to improve the geological interpretation in volcanoes and in tectonically active zones. In this review we only list but do not discuss the most significative papers showing the images obtained, as we are focused to review the method and not the interpretation of data analysis. For sake of completeness, we anyway show also a new analysis applied to data from Stromboli volcano. We thus first introduce the physical model describing the seismogram Energy Envelope (derived from the solution of the Energy Transport integral Equation) and discuss its asymptotic approximations (Diffusion- and Single-scattering model). Then, we describe a numerical method to heuristically calculate the Sensitivity Kernels for the propagation of the scattered waves in the assumption of isotropic scattering. We attribute to these Sensitivity Kernels the physical meaning of probability that for a single source-receiver couple the measured attenuation parameters can be associated with the space coordinates. Based on this definition, the attenuation image can be obtained mapping the estimated attenuation parameters onto the zone under study weighting with the Sensitivity Kernels. We further discuss how to estimate the uncertainties associated with the results and report the list of the papers describing the (separated) scattering- and intrinsic-attenuation structures investigated using this approach.
    Description: Published
    Description: id304
    Description: 1T. Struttura della Terra
    Description: JCR Journal
    Keywords: seismic scattering ; seismic imaging ; sensitivity kernels ; seismic attenuation ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Assessing Current Seismic Hazards in Irpinia Forty Years after the 1980 Earthquake: Merging Historical Seismicity and Satellite Data about Recent Ground Movements (2021)
    MDPI
    Details
    Publication Date: 2021-04-13
    Description: Recently, a new strain rate map of Italy and the surrounding areas has been obtained by processing data acquired by the persistent scatterers (PS) of the synthetic aperture radar interferome- try (InSAR) satellites—ERS and ENVISAT—between 1990 and 2012. This map clearly shows that there is a link between the strain rate and all the shallow earthquakes (less than 15 km deep) that occurred from 1990 to today, with their epicenters being placed only in high strain rate areas (e.g., Emilia plain, NW Tuscany, Central Apennines). However, the map also presents various regions with high strain rates but in which no damaging earthquakes have occurred since 1990. One of these regions is the Apennine sector, formed by Sannio and Irpinia. This area represents one of the most important seismic districts with a well-known and recorded seismicity from Roman times up to the present day. In our study, we merged historical records with new satellite techniques that allow for the precise determination of ground movements, and then derived physical dimensions, such as strain rate. In this way, we verified that in Irpinia, the occurrence of new strong shocks—forty years after one of the strongest known seismic events in the district that occurred on the 23 November 1980, measuring Mw 6.8—is still a realistic possibility. The reason for this is that, from 1990, only areas characterized by high strain rates have hosted significant earthquakes. This picture has been also confirmed by analyzing the historical catalog of events with seismic completeness for magnitude M ≥ 6 over the last four centuries. It is easy to see that strong seismic events with magnitude M ≥ 6 generally occurred at a relatively short time distance between one another, with a period of 200 years without strong earthquakes between the years 1732 and 1930. This aspect must be considered as very important from various points of view, particularly for civil protection plans, as well as civil engineering and urban planning development.
    Description: Published
    Description: 168
    Description: 4T. Sismicità dell'Italia
    Description: JCR Journal
    Keywords: Irpinia ; seismic hazard ; strain rate ; GNSS ; InSAR ; earthquake ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Co-Seismic Magnetic Field Perturbations Detected by Swarm Three-Satellite Constellation (2021)
    MDPI
    Details
    Publication Date: 2021-01-29
    Description: The first 5.3 years of magnetic data from three Swarm satellites have been systematically analyzed, and possible co-seismic magnetic disturbances in the ionosphere were investigated just a few minutes after the occurrence of large earthquakes. We preferred to limit the investigation to a subset of earthquakes selected in function of depth and magnitude. After a systematic inspection of the available data around (in time and space) the seismic events, we found 12 Swarm satellite tracks with co-seismic disturbances possibly produced by ten earthquakes from Mw5.6 to Mw6.9. The distance of the satellite to the earthquake epicenter corresponds to the measured distance-time arrival of the disturbance from the surface to the ionosphere, confirming that the identified disturbances are most likely produced by the seismic events. Secondly, we found a good agreement with a model that combined a propagation of the disturbance to the F2 ionospheric layer with an acoustic gravity wave at a velocity of about (2.2 0.3) km/s and a second faster phenomenon that transmits the disturbance from F2 layer to the Swarm satellite with a velocity of about (16 3) km/s as an electromagnetic scattering propagation.
    Description: Published
    Description: 1166
    Description: 7T. Variazioni delle caratteristiche crostali e precursori sismici
    Description: JCR Journal
    Keywords: coseismic phenomena ; ionospheric phenomena ; 01.02. Ionosphere ; 04.05. Geomagnetism ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    Near-source simulation of strong ground motion in Amatrice downtown including site effects (2021)
    MDPI
    Details
    Publication Date: 2021-04-30
    Description: On 24 August 2016, a Mw 6.0 earthquake started a damaging seismic sequence in central Italy. The historical center of Amatrice village reached the XI degree (MCS scale) but the high vulnerability alone could not explain the heavy damage. Unfortunately, at the time of the earthquake only AMT station, 200 m away from the downtown, recorded the mainshock, whereas tens on temporary stations were installed afterwards. We propose a method to simulate the ground motion affecting Amatrice, using the FFT amplitude recorded at AMT, which has been modified by the standard spectral ratio (SSR) computed at 14 seismic stations in downtown. We tested the procedure by comparing simulations and recordings of two later mainshocks (Mw 5.9 and Mw 6.5), underlining advantages and limits of the technique. The strong motion variability of simulations was related to the proximity of the seismic source, accounted for by the ground motion at AMT, and to the peculiar site effects, described by the transfer function at the sites. The largest amplification characterized the stations close to the NE hill edge and produced simulated values of intensity measures clearly above one standard deviation of the GMM expected for Italy, up to 1.6 g for PGA.
    Description: The grant of A.T. is funded by INGV and Department of Sciences, Roma Tre University (MIUR-Italy Dipartimenti di Eccellenza, Art.1, Commi 314-337 Legge 232/2016).
    Description: Published
    Description: 186
    Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica
    Description: JCR Journal
    Keywords: strong ground motion ; earthquake simulation ; near-source ; Amatrice earthquake ; seismic sequence ; site effects ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    AlpArray-Italy: Site description and noise characterization (2020)
    Copernicus Publications
    Details
    Publication Date: 2020-01-31
    Description: Within the framework of the European collaborative research initiative AlpArray (http://www.alparray.ethz. ch), the Istituto Nazionale di Geofisica e Vulcanolgia (INGV) deployed overall 20 broad-band seismic stations in Northern Italy and on two islands in the Tyrrhenian Sea (Capraia and Montecristo) during Fall-Winter 2015. The temporary deployment (16 stations) will run for two to three years and 4 INGV National Seismic Network accelerometric sites are now equipped with additional per- manent broad-band sensors. The 16 temporary stations are equipped with REF TEK 130 digitizers and Nanometrics Trillium Compact 120 s sensors, a couple have Nanometrics Trillium 120P sensors and one a Streckeisen STS2. For each site we describe the settings and discuss the noise levels, the site effects and the preliminary sensitivity analysis.
    Description: Published
    Description: 39-52
    Description: 8T. Sismologia in tempo reale
    Description: JCR Journal
    Keywords: 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Characterization of the seismic dynamical state through joint analysis of earthquakes and seismic noise: the example of Ischia Volcanic Island (Italy) (2020)
    Copernicus Publications
    Details
    Publication Date: 2020-04-09
    Description: This work is devoted to the study of both earthquakes and background seismic noise at Ischia Island (Italy) recorded pre and post the Md 4.0 earthquake occurred on 21 August 2017 (18:57 UTC). We compare and characterize noise and earthquakes in terms of Independent Component Analysis, energy and polarization properties. The earthquakes’ waveforms and the background noise are decomposed into a few independent components with two main common signals peaked around 1–2 and 3–4 Hz, respectively. A slight increase of the energy of the background seismic noise is observed comparing samples recorded in 2016 and 2017, whereas no variations are detected in 2017 pre and post the main earthquake. The polarization analysis, performed in the frequency bands individuated by Independent Component Analysis and applied to the background seismic noise, indicates a shallow propagation and the azimuthal pattern is mainly controlled by the local structural features. These results suggest that noise and earthquakes are ascribable to a common phenomenon of fluid-solid interaction in the hydrothermal system of Ischia Island.
    Description: Published
    Description: 19-28
    Description: 3T. Sorgente sismica
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    Keywords: Ischia volcano ; Source dynamics ; Data analysis ; 04.08. Volcanology ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    Seismic Ambient Noise Imaging of a Quasi-Amagmatic Ultra-Slow Spreading Ridge (2021)
    MDPI
    Details
    Publication Date: 2021-09-21
    Description: Passive seismic interferometry has become very popular in recent years in explorationgeophysics. However, it has not been widely applied in marine exploration. The purpose of thisstudy is to investigate the internal structure of a quasi-amagmatic portion of the Southwest IndianRidge by interferometry and to examine the performance and reliability of interferometry in marineexplorations. To reach this goal, continuous vertical component recordings from 43 ocean bottomseismometers were analyzed. The recorded signals from 200 station pairs were cross-correlated inthe frequency domain. The Bessel function method was applied to extract phase–velocity dispersioncurves from the zero crossings of the cross-correlations. An average of all the dispersion curveswas estimated in a period band 1–10 s and inverted through a conditional neighborhood algorithmwhich led to the final 1D S-wave velocity model of the crust and upper mantle. The obtained S-wavevelocity model is in good agreement with previous geological and geophysical studies in the regionand also in similar areas. We find an average crustal thickness of 7 km with a shallow layer of lowshear velocities and high Vp/Vs ratio. We infer that the uppermost 2 km are highly porous and maybe strongly serpentinized.
    Description: Published
    Description: 2811
    Description: 1T. Struttura della Terra
    Description: JCR Journal
    Keywords: 04.06. Seismology ; 04.01. Earth Interior
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    GIS applications in volcano monitoring: the study of seismic swarms at the Campi Flegrei volcanic complex, Italy (2021)
    Copernicus Publications
    Details
    Publication Date: 2022-03-25
    Description: Campi Flegrei caldera (Southern Italy) is one of the most hazardous volcanic complexes in the world since it is located inside the densely inhabited urban district of Naples-Pozzuoli. In the past, the caldera has produced devastating to moderate eruptions and periodically undergoes from strong to minor uplift episodes, named “bradyseism”, almost always accompanied by seismic swarms. Starting from 2005 Campi Flegrei has undergone an unrest crisis, characterized by ground uplift, localized gas emissions and seismicity, often occurring in seismic swarms. As a consequence, the monitoring activities have been progressively increasing, producing a huge amount of data, difficult to manage and match. GIS (Geographical Information System) represents a potent tool to manage great quantity of data, coming from different disciplines. In this study, we show two GIS technology applications to the seismic catalogue of Campi Flegrei. In the first one, a high-quality dataset is extracted from the GeoDatabase addressed to seismological studies that require high precision earthquake locations. In the second application, GIS are used to extract, visualize and analyse the typical seismic swarms of Campi Flegrei. Moreover, density and seismic moment distribution maps were generated for these swarms. In the last application, the GIS allow to highlight a clear variation in the temporal trend of the seismic swarms at Campi Flegrei.
    Description: This study has benefited from funding provided by the Italian Presidenza del Consiglio dei Ministri – Dipartimento della Protezione Civile.
    Description: Published
    Description: 131-144
    Description: 4V. Processi pre-eruttivi
    Description: 6SR VULCANI – Servizi e ricerca per la società
    Description: 1IT. Reti di monitoraggio e sorveglianza
    Description: N/A or not JCR
    Keywords: Campi Flegrei ; Seismic swams ; Seismic network ; GIS ; 04.06. Seismology ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...