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  • 1
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    Seawater carbonate chemistry and toxic effects of carbon nanoparticles on polychaetes (2019)
    PANGAEA
    Details
    Publication Date: 2024-03-15
    Description: Ocean acidification events are recognized as important drivers of change in biological systems. Particularly, the impacts of acidification are more severe in estuarine systems than in surface ocean due to their shallowness, low buffering capacity, low salinity and high organic matter from land drainage. Moreover, because they are transitional areas, estuaries can be seriously impacted by a vast number of anthropogenic activities and in the last decades, carbon nanomaterials (CNMs) are considered as emerging contaminants in these ecosystems. Considering all these evidences, chronic experiment was carried out, trying to understand the possible alteration on the chemical behaviour of two different CNMs (functionalized and pristine) in predicted climate change scenarios and consequently, how these alterations could modify the sensitivity of one the most common marine and estuarine organisms (the polychaeta Hediste diversicolor) assessing a set of biomarkers related to polychaetes oxidative status as well as the metabolic performance and neurotoxicity. Our results demonstrated that all enzymes worked together to counteract seawater acidification and CNMs, however oxidative stress in the exposed polychaetes to both CNMs, especially under ocean acidification conditions, was enhanced. In fact, although the antioxidant enzymes tried to cope as compensatory response of cellular defense systems against oxidative stress, the synergistic interactive effects of pH and functionalized CNMs indicated that acidified pH significantly increased the oxidative damage (in terms of lipid peroxidation) in the cotaminated organisms. Different responses were observed in organisms submitted to pristine CNMs under pH control, where the lipid peroxidation did not increase along with the increasing exposure concentrations. The present results further demonstrated neurotoxicity caused by both CNMs, especially noticeable at acidified conditions. The mechanism of enhanced toxicity could be attributed to slighter aggregation and more suspended NMs in acidified seawater (as demonstrated by the DLS analysis). Therefore, ocean acidification may cause a higher risk of CNMs to marine ecosystems.
    Keywords: Acetylcholinesterase activity, per fresh mass, standard deviation; Acetylcholinesterase activity per fresh mass; Alkalinity, total; Alkalinity, total, standard deviation; Animalia; Annelida; Aragonite saturation state; Aragonite saturation state, standard deviation; Benthic animals; Benthos; Bicarbonate ion; Bicarbonate ion, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Catalase, per wet mass; Catalase activity, standard deviation; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); Electron transport system activity of oyxgen; Electron transport system activity of oyxgen, standard deviation; Experiment day; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Glutathione reductase per fresh mass; Glutathione reductase per fresh mass, standard deviation; Glycogen; Glycogen, standard deviation; Hediste diversicolor; Laboratory experiment; Lipid peroxidation, per wet mass; Lipid peroxidation, standard deviation; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Other metabolic rates; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH, standard deviation; Polydispersity index; Potentiometric; Potentiometric titration; Proteins, standard deviation; Proteins per fresh mass; Registration number of species; Salinity; Salinity, standard deviation; Single species; Size; Species; Superoxide dismutase, per fresh mass; Superoxide dismutase activity, standard deviation; Temperate; Temperature, water; Temperature, water, standard deviation; Treatment; Type; Uniform resource locator/link to reference
    Type: Dataset
    Format: text/tab-separated-values, 2038 data points
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    DATA PANGAEA
  • 2
    Electronic Resource
    Electronic Resource
    Body Wave Traveltimes and A Spherically Symmetric P- and S-Wave Velocity Model (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 112 (1993), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The derivation of a spherically-symmetric reference earth model is a subject which has recently regained interest. After a decade of studies on lateral heterogeneity we now have the tools to approach the problem. an IASPEI Working Group on Traveltime Tables was formed in 1988 with the goal of deriving a reliable and up-to-date radial model of seismic velocities. Following the guidelines developed by that working group we have investigated the body wave traveltimes for several branches frequently reported in the ISC Bulletins and propose here a model for P-and S-wave velocities consistent with these data.Approximately 16000 best-recorded, shallow-focus earthquakes are selected from 24 years of ISC Bulletins (1964-1987) and relocated using, among others corrections for lateral heterogeneity. From this dataset we derive summary traveltime curves specified for each degree of epicentral distance for P, PcP-P, PKPAB, PKPBC, PKIKP and S. to constrain velocity at the top of the outer core, we include data for SKS and SKKS-SKS From Hales & Roberts (1970, 1971). Our discrete time-distance curves are obtained by evaluating the shape of the residual density distribution, independently for each 1° interval, to limit contamination due to the interference of other branches, precursors or late readings.In the upper mantle, the resulting model, SP6, differs from iasp91 (Kennett & Engdahl 1991) only by slightly higher P and S velocities between 410 and 660 km. In the lower mantle, new velocity profiles have lower velocity gradients. This is also true in comparison with PREM (Dziewonski & Anderson 1981). At the top of the outer core vp is smaller than in PREM, and the velocity jump at the inner core boundary is reduced to the value of 0.62 km s-1. the new inner core radius is 1215 km. Our model predicts traveltimes that differ from the iasp91 tables considerably, although generally less than 1 s, except for SKS and SKKS for which the differences are greater.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1993.tb01448.x
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    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Topography of the core–mantle boundary and lateral homogeneity of the liquid core (1987)
    [s.l.] : Nature Publishing Group
    Nature 325 (1987), S. 678-683 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Separate inversions of travel-time residuals of waves reflected from and transmitted through the core-mantle boundary yield similar results in terms of spherical harmonic expansion of its topography up to degree and order 4. This indicates absence of detectable lateral heterogeneity in the liquid ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/325678a0
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    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Source properties of the 1997–98 Central Italy earthquake sequence from inversion of long-period and broad-band seismograms (2000)
    Springer
    Journal of seismology 4 (2000), S. 365-375 
    Details
    ISSN: 1573-157X
    Keywords: body waves ; Central Apennines ; extensional tectonic regime ; focal depths ; seismic moment tensors ; source mechanisms ; source time functions ; surface waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We study source properties of the main earthquakes of the 1997–98 Umbria-Marche (central Italy) sequence by analysis of regional-distanceand teleseismic long period and broadband seismograms recorded by MedNet and IRIS/GSN stations. We use a modified Harvardcentroid-moment tensor (CMT) algorithm to allow inversion of long period waveforms, primarily Rayleigh and Love waves, for small earthquakes (4.2 ≤ MW ≤ 5.5) at local to regional distances (Δ〈15°). For the seven largest earthquakes (MW〉5.2) moment tensors derived from local and regional data agree well with those determined using teleseismic waveforms and standard methods of analysis. We also determine moment tensors for a foreshock and 12 other aftershocks, that were too small for global analysis. Focal depth and rupture propagation are analyzed for three largest shocks by inversion of teleseismic broadband body waves. The earthquakes are generally located at shallow depth (5 km or shallower) and are characterized by normal faulting mechanisms, with a NE-SW tension axis. The presumed principal fault plane dips at a shallow angle towards the SW. Only one of the events analyzed has an entirely different faulting geometry, indicating instead right-lateral strike-slip motion on a plane approximately E-W, or left-lateral faulting on a N-S plane. The other significant exception to the regular pattern of mechanisms is represented by the March 26, 1998, event, located at 51 km depth. Its connection with the shallow earthquake sequence is unclear and intriguing. The time evolution of the seismic sequence is unusual,with the mainshock accounting for only approximately 50% of the total moment release. The broadband teleseismic waveforms of the main, September 26, 09:40, earthquake are very complicated for the size of the event and suggest a complex rupture. In our favored source model, rupture initiated at 5 km depth, propagated updip and was followed, 3 seconds later, by a shallower subevent with a slightly rotated mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026587817690
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    Paper (German National Licenses)
    Fulltext
  • 5
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    Development and Testing of a 3D Seismic Velocity Model of the Po Plain Sedimentary Basin, Italy (2015)
    SSN (Seismological Society of America)
    In:  Bulletin of the Seismological Society of America, 105 (2A). pp. 753-764.
    Details
    Publication Date: 2021-05-03
    Description: We built a 3D seismic model of the Po Plain and neighboring regions of northern Italy, covering altogether an area about 600 km by 300 km with an approximately 1 km spaced grid. We started by collecting an extensive and diverse set of geological and geophysical data, including seismic reflection and refraction profiles, borehole logs, and available geological information. Major geological boundaries and discontinuities have thus been identified and mapped into the model. We used kriging to interpolate the geographically sparse information into continuous surfaces delimiting geological bodies with laterally varying thickness. Seismic-wave properties have been assigned to each unit using a rule-based system and, VP, VS, and ρ derived from other studies. Sedimentary strata, although with varying levels of compaction and hence material properties, may locally reach a thickness of 15 km and give rise to significant effects in seismic-wave propagation.We have used our new model to compute the seismic response for two recent earthquakes, to test its performance. Results show that the 3D model reproduces the large amplitude and the long duration of shaking seen in the observed waveforms recorded on sediments, whereas paths outside the basin may be well fit by more homogeneous (1D) hard rock structure. We conclude that the new model is suited for simulation of wave propagation, mostly for T 〉 3 s, and may serve well as a constraint for earthquake location and further improvements via body- or surface-wave inversion.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1785/0120140204
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 6
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    Images of the Iberian Lithosphere from One Local Earthquake (2011)
    Seismological Society of America (SSA)
    Details
    Publication Date: 2011-04-01
    Description: On 12 August 2007, a magnitude Mw 4.7 intraplate earthquake occurred near the center of the Iberian Peninsula, an area characterized by comparably simple crustal structure within the complex Iberia-Maghreb plate boundary zone, and characterized by complete azimuthal coverage with seismic broadband stations. We analyze regional intermediate-period (20- to 50-s) coda waveforms for this earthquake. They contain energy representing late-arriving surface waves that have been reflected laterally at lithospheric heterogeneities in or around Iberia, but complexity of the coda waveforms hampers a direct interpretation. We use coda recordings as the source for a back-propagating adjoint wave field and compute 3D Born sensitivity kernels for the dependence of least-squares waveform misfits of coda waves on wave speed variations. We hereby image the origin of single scattering recorded in the coda. Misfit kernels for P- and S-wave velocity show azimuth-dependent intensity variation as a result of source radiation, and an appropriate compensation significantly improves imaging quality, thereby revealing several clear lineaments. These are interpreted as surface-wave reflectors due to deep-rooted heterogeneity such as terrain boundaries or Moho topography, demonstrating the ability of the approach to unravel complex waveforms, and providing a new point of view on regional lithospheric structure.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences , Physics
    Published by Seismological Society of America (SSA)
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    PAPER CURRENT
  • 7
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    Feasibility studies towards a probabilistic seismic hazard analysis for hydrocarbon extraction and wastewater injection activities (2020)
    http://www3.ogs.trieste.it/gngts/files/2018/S23/Riassunti/GarciaAristizabal1.pdf
    Details
    Publication Date: 2020-09-08
    Description: In recent years, great efforts have been devoted to the study of the human-induced earthquakes, owing to the effect that these earthquakes can have in terms of seismic hazard. In the past, different authors proposed classification schemes for distinguishing different mechanisms for fluid-induced seismicity generation (see, e.g. McGarr 2000). For example, it has been suggested that when the anthropic activities are responsible for a very small part of the stress field perturbations, the seismic events can be classified as “triggered”, while when the anthropic activities are responsible for the most of stress perturbations driving to the event occurrence, it can be classified as “induced”. In practice, we can rather consider that it may exist a continuum of cases depending on both the characteristics of technological operations and the local stress state.
    Description: Ministero di Sviluppo Economico, Direzione Generale per le Infrastrutture e la Sicurezza dei Sistemi Energetici e Geominerari (DG ISSEG)
    Description: Published
    Description: Bologna
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Keywords: Hazard sismico ; Sismicità indotta ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
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  • 8
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    Application of monitoring guidelines to induced seismicity in Italy (2020)
    Springer
    Details
    Publication Date: 2020-11-12
    Description: Public concern about anthropogenic seismic- ity in Italy first arose in the aftermath of the deadly M ≈ 6 earthquakes that hit the Emilia-Romagna region (northern Italy) in May 2012. As these events occurred in a (tectonically active) region of oil and gas production and storage, the question was raised, whether stress perturbations due to underground industrial activities could have induced or triggered the shocks. Following expert recommendations, in 2014, the Italian Oil & Gas Safety Authority (DGS-UNMIG, Ministry of Economic Development) published guidelines (ILG - Indirizzi e linee guida per il monitoraggio della sismicità, delle deformazioni del suolo e delle pressioni di poro nell’ambito delle attività antropiche), describing regula- tions regarding hydrocarbon extraction, waste-water in- jection and gas storage that could also be adapted to other technologies, such as dams, geothermal systems, CO2 storage, and mining. The ILG describe the frame- work for the different actors involved in monitoring activities, their relationship and responsibilities, the procedure to be followed in case of variations of mon- itored parameters, the need for in-depth scientific anal- yses, the definition of different alert levels, their mean- ing and the parameters to be used to activate such alerts. Four alert levels are defined, the transition among which follows a decision to be taken jointly by relevant au- thorities and industrial operator on the basis of evalua- tion of several monitored parameters (micro-seismicity, ground deformation, pore pressure) carried on by a scientific-technical agency. Only in the case of liquid reinjection, the alert levels are automatically activated on the basis of exceedance of thresholds for earthquake magnitude and ground shaking – in what is generally known as a Traffic Light System (TLS). Istituto Nazionale di Geofisica e Vulcanologia has been charged by the Italian oil and gas safety authority (DGS- UNMIG) to apply the ILG in three test cases (two oil extraction and one gas storage plants). The ILG indeed represent a very important and positive innovation, as they constitute official guidelines to coherently regulate monitoring activity on a national scale. While pilot studies are still mostly under way, we may point out merits of the whole framework, and a few possible critical issues, requiring special care in the implementa- tion. Attention areas of adjacent reservoirs, possibly licenced to different operators, may overlap, hence mak- ing the point for joint monitoring, also in view of the possible interaction between stress changes related to the different reservoirs. The prescribed initial blank- level monitoring stage, aimed at assessing background seismicity, may lose significance in case of nearby ac- tive production. Magnitude – a critical parameter used to define a possible step-up in activation levels – has inherent uncertainty and can be evaluated using differ- ent scales. A final comment considers the fact that relevance of TLS, most frequently used in hydraulic fracturing operations, may not be high in case of trig- gered tectonic events.
    Description: Published
    Description: 1015–1028
    Description: 1IT. Reti di monitoraggio e sorveglianza
    Description: JCR Journal
    Keywords: Anthropogenic seismicity ; Alert system ; Monitoring guidelines ; 04.06. Seismology ; 05.04. Instrumentation and techniques of general interest
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 9
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    Epistemic Uncertainties in Local Earthquake Locations and Implications for Managing Induced Seismicity (2020)
    SSA
    Details
    Publication Date: 2020-11-12
    Description: Earthquake hypocentral location is perhaps the most classical problem in seismology, the solution of which is often affected by significant uncertainty. In monitoring the effects of underground anthropogenic activities, the earthquake hypocentral location, magnitude, and ground motions are important parameters for managing induced seismicity (as e.g., for operating traffic‐light systems). Such decisional systems define the operative reactions to be enacted once an earthquake, exceeding some magnitude or ground‐motion threshold, occurs within a monitoring volume defined in the neighborhood of a certain anthropogenic underground activity. In this case, a reliable evaluation of the hypocentral location, along with its uncertainty, becomes crucial for rational decision making. In this article, we analyze different sources of uncertainty that can be relevant for the determination of earthquake source locations, and introduce a logic‐tree‐based ensemble modeling approach for framing the problem in a decision‐making context. To demonstrate the performance of the proposed approach, we analyze uncertainties in the location of a seismic event that occurred on 22 July 2019 within the perimeter of the monitoring domain defined in the Val d’Agri oil field (southern Italy). We cast the result as a model ensemble that allows us to obtain samples from a parent distribution that better represents both aleatory and epistemic uncertainties of the earthquake location problem. We find that often‐neglected epistemic uncertainties (i.e., those that arise when considering alternative plausible modeling approaches or data) can be considerably larger and more representative of the state of knowledge about the source location, than the standard errors usually reported by the most common algorithms. Given the consequential repercussions of decision making under uncertainty, we stress that an objective evaluation of epistemic uncertainties associated with any parameter used to support decisional processes must be a priority for the scientific community.
    Description: Centro per il Monitoraggio delle attività di Sottosuolo (CMS).
    Description: Published
    Description: 2423–2440
    Description: 3SR TERREMOTI - Attività dei Centri
    Description: JCR Journal
    Keywords: Earthquake location ; uncertainty ; Traffic light systems ; Decision making ; 04.06. Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 10
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    Effect of Groundwater on Noise-Based Monitoring of Crustal Velocity Changes Near a Produced Water Injection Well in Val d'Agri (Italy) (2021)
    Details
    Publication Date: 2021-05-06
    Description: We study the crustal velocity changes occurred at the restart of produced water injection at a well in the Val d'Agri oil field in January–February 2015 using seismic noise cross-correlation analysis. We observe that the relative velocity variations fit well with the hydrometric level of the nearby Agri river, which may be interpreted as a proxy of the total water storage in the shallow aquifers of the Val d'Agri valley. We then remove from the relative velocity trend the contribution of hydrological variations and observe a decrease in relative velocity of ≈ 0.08% starting seven days after the injection restart. In order to investigate if this decreasing could be due to the water injection restart, we compute the medium diffusivity from its delay time and average station-well distance. We found diffusivity values in the range 1–5 m2/s, compatible with the observed delay time of the small-magnitude (ML ≤ 1.8) induced seismicity occurrences, triggered by the first injection tests in June 2006 and with the hydraulic properties of the hydrocarbon reservoir. Our results show that water storage variations can not be neglected in noise-based monitoring, and they can hide the smaller effects due to produced water injection.
    Description: Published
    Description: 626720
    Description: 7T. Variazioni delle caratteristiche crostali e "precursori"
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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