ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Publication Date: 2021-12-15
    Description: Italy's Mt.Vesuvius has been slumbering for a long time, but its silence could preface an eruption with potentially disastrous ef­fects for 600,000 people living on the vol­cano's slopes. To assess the scenario of the next eruption, the National Group of Vol-canology (GNV) of the Italian National Coun­cil of Researches (CNR) has fostered research aimed at mitigating eruption risk to the densely populated area. In this framework, researchers have gathered high-resolution seismic tomography data to better under­stand the internal structure of Mt. Vesuvius. The experiments were carried out during the last 4 years. The data will be used in three-dimen­sional modeling of the structure of Mt. Vesu­vius and underlying upper crust. Seismic velocities and attenuation and density con­trasts will be calculated, with special empha­sis on the delineation of significant magma reservoirs of more than 1 km in diameter. In modeling Mt. Vesuvius, tools are being devel­oped for using seismogram information to ob­tain high-quality seismic imaging of heterogeneous structures such as volcanoes
    Description: Published
    Description: 229-230, 232
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: N/A or not JCR
    Keywords: Tomography
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2022-02-18
    Description: After some centuries of subsidence, following the AD 1538 Monte Nuovo last eruption, the Campi Flegrei caldera has shown unrest episodes since at least 1950. The first uplift episode dates back to 1950–1952 and amounted to 73 cm, without any report or record of seismic activity. Two strong infla- tion episodes occurred in 1970–1972 and 1982–1984. The first accompanied by moder- ate low seismicity, with only few events felt by the population, whereas the second was accompanied by relatively intense swarms of volcano-tectonic earthquakes, reaching up to magnitude 4. The seismic activity caused alarm in the population and a spontaneous nightly evacuation of part of the town of Pozzuoli (44,000 inhabitants). Since this last episode, subsidence has been recorded for several years, interrupted by some mini-uplift events, lasting several weeks and accompa- nied by seismic swarms of low-magnitude volcano-tectonic events. In recent years, high sensitivity instruments have been installed to detect slow earthquake transients and other mechanical/temperature low-intensity precur- sory signals. Since late 2004 another moderate uplift is occurring at very small rate, amount- ing to about 1–2 cm/year, accompanied by long-period events. This uplift is different from the past mini-uplift events due to its duration. This work summarises all seismic and ground deformation data as well as the models proposed to interpret these phenom- ena, suggesting possible methods for detecting precursors of future eruptive activity in the area.
    Description: Published
    Description: 257-282
    Description: 1V. Storia eruttiva
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2022-02-24
    Description: Reliable seismic hazard analyses are crucial to mitigate seismic risk. When dealing with induced seismicity the standard Probabilistic Seismic Hazard Analysis (PSHA) has to be modified because of the peculiar characteristics of the induced events. In particular, the relative shallow depths, small magnitude, a correlation with field operations, and eventually non-Poisson recurrence time. In addition to the well-known problem of estimating the maximum expected magnitude, it is important to take into account how the industrial field operations affect the temporal and spatial distribution of the earthquakes. In fact, during specific stages of the project the seismicity may be hard to be modelled as a Poisson process—as usually done in the standard PSHA—and can cluster near the well or migrate toward hazardous known or—even worse—not known faults. Here we present a technique in which we modify the standard PSHA to compute time-dependent seismic hazard. The technique allows using non-Poisson models (BPT, Weibull, gamma and ETAS) whose parameters are fitted using the seismicity record during distinct stages of the field operations. As a test case, the procedure has been implemented by using data recorded at St. Gallen deep geothermal field, Switzerland, during fluid injection. The results suggest that seismic hazard analyses, using appropriate recurrence model, ground motion predictive equations, and maximum magnitude allow the expected ground-motion to be reliably predicted in the study area. The predictions can support site managers to decide how to proceed with the project avoiding adverse consequences.
    Description: Published
    Description: 2747
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2022-02-24
    Description: Focal mechanisms of selected earthquakes, recorded in the Mount Pollino region (southern Italy) from 2010 through 2014, are used to infer the pore fluid pressure at hypocenter depths. The 3-D excess pore pressure field provides evidence that the sequence occurs in a fluid-filled volume with values reaching 35 MPa. The mechanisms underlying this swarm-like sequence and the triggering of earthquakes are investigated by computing the cumulative static Coulomb stress change at hypocenter depths and analyzing the pore-pressure diffusion mechanism. The results indicate that static Coulomb stress change was lower than 0.01 MPa, which is the value generally assumed as threshold for the triggering, and seismicity distribution was actually driven by pore-pressure diffusion with relatively low diffusivity value. This latter mechanism could also explain the delayed triggering of the two larger events ML 4.3 and ML 5.0, respectively, that occurred about 150 days apart.
    Description: Published
    Description: e2021GL094552
    Description: 3T. Fisica dei terremoti e Sorgente Sismica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2022-02-25
    Description: Studying the spatiotemporal distribution and motion of water vapour (WV), the most variable greenhouse gas in the troposphere, is pivotal, not only for meteorology and climatology, but for geodesy, too. In fact, WV variability degrades, in an unpredictable way, almost all geodetic observation based on the propagation of electromagnetic signal through the atmosphere. We use data collected on a dense GPS network, designed for the purposes of monitoring the active Neapolitan (Italy) volcanoes, to retrieve the tropospheric delay parameters and precipitable water vapour (PWV). This study has two main targets: (a) the analysis of long datasets (11 years) to extract trends of climatological meaning for the region; (b) studying the main features of the time evolution of the PWV during heavy raining events to gain knowledge on the preparatory stages of highly impacting thunderstorms. For the latter target, both differential and precise point positioning (PPP) techniques are used, and the results are compared and critically discussed. An increasing trend, amounting to about 2 mm/decades, has been recognized in the PWV time series, which is in agreement with the results achieved in previous studies for the Mediterranean area. A clear topographic effect is detected for the Vesuvius volcano sector of the network and a linear relationship between PWV and altitude is quantitatively assessed. This signature must be taken into account in any modelling for the atmospheric correction of geodetic and remote-sensing data (e.g., InSAR). Characteristic temporal evolutions were recognized in the PWV in the targeted thunderstorms (which occurred in 2019 and 2020), i.e., a sharp increase a few hours before the main rain event, followed by a rapid decrease when the thunderstorm vanished. Accounting for such a peculiar trend in the PWV could be useful for setting up possible early warning systems for those areas prone to flash flooding, thus potentially providing a tool for disaster risk reduction.
    Description: TRYAT (TRack Your ATmosphere) project (2017-1-DE02-KA202-004229) Co-funded by ERASMUS + Programme of the European Union.
    Description: Published
    Description: 1225
    Description: 7A. Geofisica per il monitoraggio ambientale
    Description: JCR Journal
    Keywords: GNSS ; troposphericdelay ; precipitable water vapour ; thunderstorm ; Somma Vesuvius
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2022-02-25
    Description: We simulate the deformation of Somma-Vesuvius volcano due to some overpressure sources by means of a finite element 3D code. The main goal of these simulations is to investigate the influence of topography and structural heterogeneity on ground deformation. In our model the sources of deformation are embedded in an elastic linear isotropic medium and located at various depths. Geometry (shape and lateral extension) of the sources is mainly constrained by the results coming from recent seismic tomography studies. The structural heterogeneity has been modelled in terms of dynamic elastic parameters (Young’s modulus) retrieved from previous seismic tomography and gravity studies. A highresolution digital terrain model is used for the topography of the volcano subaerial edifice. Evidences from our results suggest that real topography and structural heterogeneities are key factors governing the ground deformation, which often turns being one of the most relevant problems in volcano monitoring. A large deviation from the axially symmetrical model of the displacement field is the main result of our modelling. Such an asymmetry is routinely unaccounted for when Mogi’s simplistic modelling in a homogeneous medium with simplified topography is used. Our study clearly demonstrate that a better knowledge of deformation patterns can significantly help in the location of monitoring sensors as well as in the design of an efficient geodetic network.
    Description: Published
    Description: 145-152
    Description: 4V. Processi pre-eruttivi
    Description: N/A or not JCR
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2022-02-25
    Description: In this study, we investigate the oscillations of relative sea level through the analysis of tide gauge records about 10-year long collected in the Gulfs of Pozzuoli and Napoli (Southern Italy). The main goal of this study is to provide a suitable resolution model of the sea tides including low frequency (seiches), tidal bands and non-linear tides. The spectral analyses of the tide gauge records lead us to identify a number of seiche periods some of them already known from the literature and some other unknown. Furthermore, we target a non-conventional purpose of the tidal analysis, namely extracting from the tide gauge records the volcanotectonic signal (vertical ground displacement) in the resurgent Campi Flegrei caldera. We suggest a method to filter out the volcano-tectonic signal (bradyseism) from the tide gauge records by deconvolving it from two records, one collected in the active volcanic area (Pozzuoli) and the other one collected in a tectonically stable station (Napoli), located beyond the caldera rim. Finally, we retrieve the relative mean sea level change in the Gulf of Naples and compare it with the trend found in five tide gauges spread along the Italian coast.
    Description: This research has been partially supported by the Dipartimento della Protezione Civile Italiana (DPC – Italian Civil Protection Department) and the MUR (Ministero dell’Università e della Ricerca, INGV Pianeta Dinamico project (code INGV 1020.010), Task V1 – 2020).
    Description: Published
    Description: 105-118
    Description: 4V. Processi pre-eruttivi
    Description: 7A. Geofisica per il monitoraggio ambientale
    Description: N/A or not JCR
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2022-02-14
    Description: A tomographic analysis of Mt. Pollino area (Italy) has been performed using earthquakes recorded in the area during an intense seismic sequence that occurred between 2010 and 2014. 870 local earthquakes with magnitude ranging from 1.8 to 5.0 were selected considering the number of recording stations, the signal quality, and the hypocenter distribution. P- and S-wave arrival times were manually picked and used to compute 3D velocity models through tomographic seismic inversion. The resulting 3D distributions of VP and VS are characterized by high resolution in the central part of the investigated area and from surface to about 10 km below sea level. The aim of the work is to obtain high- quality tomographic images to correlate with the main lithological units that characterize the study area. The results will be important to enhance the seismic hazard assessment of this complex tectonic region. These images show the ductile Apennine platform (VP = 5.3 km/s) overlaying the brittle Apulian platform (VP=6.0 km/s) at depth of around 5 km. The central sector of the area shows a clear fold and thrust interface. Along this structure,most of the seismicity occurred, including the strongest event of the sequence (M W 5.0). High V P (〉6.8 km/s) and high V P /VS (〉1.9) patterns, intersecting the southern edge of this western seismogenic volume, have been interpreted as water saturated rocks, in agreement with similar geological context in the Apennines. These fluids could have played a role in nucleation and development of the seismic sequence. A recent study revealed the occurrence of clusters of earthquakes with similar waveforms along the same seismogenic volume. The hypocenters of these cluster events have been compared with the events re-located in this work. Jointly, they depict a 10 km × 4 km fault plane, NW-SE oriented, deepening towards SW with a dip angle of 40–45° . Instead, the volume of seismicity responsible for the M L 4.3 earthquake developed as a mainshock-aftershock sequence, occurring entirely within the average-to-low VP /VS Apennine platform. Our results agree with other independent geophysical analyses carried out in this area, and they could significantly improve the actual knowledge of the main lithologic units of this complex tectonic area.
    Description: Published
    Description: 735340
    Description: 4T. Sismicità dell'Italia
    Description: JCR Journal
    Keywords: elocity tomography, crustal structure, seismic sequence, geodynamics and seismicity, Italian Apennine, Pollino, seismic gap
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...