49 research outputs found
An augmented seismic network to study off-shore seismicity around the Maltese Islands : the FASTMIT experiment
Appropriate planning and deployment of a seismic network is a prerequisite to efficiently monitor seismic activity, determine the seismic source, and eventually contribute to the seismotectonic interpretation and seismic hazard assessment. The evaluation and effectiveness of a local network on the Maltese islands, recently extended by a further six seismic stations for one year, is presented. We investigate the new temporary network's data and site selection quality, utilizing spectral patterns in the seismic data and also evaluate the network's event location performance by relocating a number of recorded events. The results will be signifi cant for the future installation of permanent seismic stations on the Maltese islands.peer-reviewe
Seismic hazard for the Trans Adriatic Pipeline (TAP). Part 2: broadband scenarios at the Fier Compressor Station (Albania)
AbstractTo ensure environmental and public safety, critical facilities require rigorous seismic hazard analysis to define seismic input for their design. We consider the case of the Trans Adriatic Pipeline (TAP), which is a pipeline that transports natural gas from the Caspian Sea to southern Italy, crossing active faults and areas characterized by high seismicity levels. For this pipeline, we develop a Probabilistic Seismic Hazard Assessment (PSHA) for the broader area, and, for the selected critical sites, we perform deterministic seismic hazard assessment (DSHA), by calculating shaking scenarios that account for the physics of the source, propagation, and site effects. This paper presents a DSHA for a compressor station located at Fier, along the Albanian coastal region. Considering the location of the most hazardous faults in the study site, revealed by the PSHA disaggregation, we model the ground motion for two different scenarios to simulate the worst-case scenario for this compressor station. We compute broadband waveforms for receivers on soft soils by applying specific transfer functions estimated from the available geotechnical data for the Fier area. The simulations reproduce the variability observed in the ground motion recorded in the near-earthquake source. The vertical ground motion is strong for receivers placed above the rupture areas and should not be ignored in seismic designs; furthermore, our vertical simulations reproduce the displacement and the static offset of the ground motion highlighted in recent studies. This observation confirms the importance of the DSHA analysis in defining the expected pipeline damage functions and permanent soil deformations
Production of biogas - a manner of manufacturing
Advertising is commonly criticised for being pervasive, offensive, manipulative, harmful
and irresponsible. This thesis focuses on the subjective criticisms and complex issues
related to taste, decency, morality and offence, particularly as applied to, and
understood within, the public and non-profit contexts. It is positioned at the intersection
of marketing communications, marketing ethics, and social and non-profit marketing
and explores how shocking, offensive and/or controversial (SOC) advertising appeals
are interpreted, regulated and contested, by divergent groups of people. The approach
taken is inspired by stakeholder theory and its focus on ethical decision-making for the
betterment of all stakeholders. A mixed methods research design was adopted, resulting
in three studies and these are presented as three discrete articles.
Article I maps the field of existing research into SOC advertising and identifies gaps in
our knowledge by means of a systematic literature review. It offers a critical appraisal
of the field by highlighting definitional tensions, limited interdisciplinary work and an
overdependence on student samples, on quantitative analysis and on non-longitudinal
methodologies. It then proposes a series of remedies to these shortcomings. The second
and third papers continue this reparative work by conceptualising and analysing actual
SOC advertising interpretations and contestations.
Article II explores the interpretations and experiences of SOC advertising within the
regulatory context by analysing evidence from complainants, advertisers and regulatory
bodies. It then proposes and develops an interpretation of the implicit power dynamics
through which their contradictory interests overlap. The methodology underpinning
this chapter combines a thematic content analysis of a substantial archive of complaints
submitted to the Advertising Standards Authority (ASA) with an interpretation of case
adjudication reports influenced by the work of Michel Foucault. The findings suggest
that the regulation of SOC advertising prioritises the interests of firms and advertisers
by relegating the role of complainant to that of merely registering complaints.
The focus of Article III moves from the regulatory framework to the complained-about
advertisements themselves. It provides an innovative theoretical and methodological
approach to analysing SOC advertisements, rooted in the classic Aristotelian notion of
rhetorical appeals and figuration, by developing and analysing a carefully selected
example in detail. The analysis reveals an implicit NFP sector-specific appeal to ethos
and the importance of a complex appeal to pathos.
Each of the papers offers a different level of analysis of the often-contradictory
viewpoints represented by stakeholder groups involved in, or affected by, the use of
SOC advertising tactics. These viewpoints include academics, general consumers, the
vocal minority of complainants, the advertisers including the non-profit and public
organisations and the advertising creatives, and the advertising regulator. Taken
together, the papers amount to a thesis that makes an important contribution to debates
about the appropriateness, ethics, and application of SOC themes, formats and imagery
in social and non-profit advertising. By exploring the regulatory processes of the ASA,
an exemplary advertising self-regulatory body, it further contributes to the discourse
on self-regulatory practices and highlights an NFP sector-specific consequentialist
approach that appears to stifle the voice of the offended complainant. On a practical
level, this work has implications for advertising practitioners and advertising regulators
who are involved in producing and regulating advertising that uses SOC tactics
Group velocity tomography in the Subantarctic Scotia Sea region.
More than 150 events, recently recorded by seven seismic broadband stations (OGS- IAA, IRIS, GSETT3-IDC), have been collected and processed to obtain an overview of the crust and upper mantle shear wave velocities.
Group velocities of the fundamental mode Rayleigh and Love waves, in the period range from 15 s to 50 s, are used to obtain tomographic maps of the Scotia Sea region, the tip of Antarctic Peninsula, and the tip of South America. Errors in the measurements, estimated on clusters, are larger for Love waves than for Rayleigh waves and their averages are 0.060\u20130.080 km/s and 0.030\u20130.040 km/s, respectively.
From the regionalisation of the dispersion measurements, we obtain smoothed local dispersion curves in correspondence with the main geological and tectonic features, and from their nonlinear inversion, the shear wave velocity versus depth profiles.
The correlation length of the heterogeneity, which can be resolved by Rayleigh waves, varies between 200 and 400 km in most parts of the studied area, but becomes greater near the periphery of the maps. The spatial resolution of Love waves (400\u2013600 km) is poorer than that of Rayleigh waves, due to the deteriorated path coverage and to the larger errors in the group velocity measurements.
Models of the shear wave velocity in the crust and upper mantle for the tip of South America, the Falkland Plateau, the Scotia Sea, the South Sandwich oceanic spreading ridge, the South Sandwich trench, the South Scotia ridge, the tip of Antarctic Peninsula, the Bransfield Strait and the Drake Passage are presented.
Our regional models and the existing large-scale models (e.g., CRUST5.1), help to define a 3-D velocity model of the Scotia Sea region to be further investigated by waveform inversion
Suboceanic Rayleigh Waves in the 1755 Lisbon Earthquake
Moderate-magnitude shallow earthquakes in the Atlantic Ocean, hundreds of kilometres southwest of Lisbon, can generate efficient suboceanic Rayleigh waves (SRW) that are well recorded in Portugal. Here we compare moderate-size earthquakes recorded by seismic stations in Portugal with the Tyrrhenian Sea earthquakes recorded in peninsular Italy where SRW were recently observed. In spite of a different behaviour of high frequencies due to the different tectonic setting of the two areas, similar results are found in the intermediate-period range, suggesting that this effect, if extrapolated to a magnitude larger than 8, could be devastating at regional distance in terms of ground motion amplitude and duration. Through 1D models, we explore the hypothesis that the high level of destruction and the long duration of shaking felt during the Great 1755 Lisbon earthquake were caused by SRW. In this preliminary study, we check the role of critical model parameters. We find that duration and amplitude are largest when the average thickness of the water layer is 2 km and shear-wave velocity of the ocean floor is close to the speed of sound in the water. Both conditions are realistic for a source in the Atlantic Ocean, few hundreds of kilometres southwest of Lisbon. Moreover, the propagation of SRW at regional distances accounts for durations of more than ten minutes as the effect of a single large earthquake.Published283-2954.1. Metodologie sismologiche per l'ingegneria sismicaope
High-Resolution Crustal S-wave Velocity Model and Moho Geometry Beneath the Southeastern Alps: New Insights From the SWATH-D Experiment
We compiled a dataset of continuous recordings from the temporary and permanent seismic networks to compute the high-resolution 3D S-wave velocity model of the Southeastern Alps, the western part of the external Dinarides, and the Friuli and Venetian plains through ambient noise tomography. Part of the dataset is recorded by the SWATH-D temporary network and permanent networks in Italy, Austria, Slovenia and Croatia between October 2017 and July 2018. We computed 4050 vertical component cross-correlations to obtain the empirical Rayleigh wave Green’s functions. The dataset is complemented by adopting 1804 high-quality correlograms from other studies. The fast-marching method for 2D surface wave tomography is applied to the phase velocity dispersion curves in the 2–30 s period band. The resulting local dispersion curves are inverted for 1D S-wave velocity profiles using the non-perturbational and perturbational inversion methods. We assembled the 1D S-wave velocity profiles into a pseudo-3D S-wave velocity model from the surface down to 60 km depth. A range of iso-velocities, representing the crystalline basement depth and the crustal thickness, are determined. We found the average depth over the 2.8–3.0 and 4.1–4.3 km/s iso-velocity ranges to be reasonable representations of the crystalline basement and Moho depths, respectively. The basement depth map shows that the shallower crystalline basement beneath the Schio-Vicenza fault highlights the boundary between the deeper Venetian and Friuli plains to the east and the Po-plain to the west. The estimated Moho depth map displays a thickened crust along the boundary between the Friuli plain and the external Dinarides. It also reveals a N-S narrow corridor of crustal thinning to the east of the junction of Giudicarie and Periadriatic lines, which was not reported by other seismic imaging studies. This corridor of shallower Moho is located beneath the surface outcrop of the Permian magmatic rocks and seems to be connected to the continuation of the Permian magmatism to the deep-seated crust. We compared the shallow crustal velocities and the hypocentral location of the earthquakes in the Southern foothills of the Alps. It revealed that the seismicity mainly occurs in the S-wave velocity range between ∼3.1 and ∼3.6 km/s
Suboceanic Rayleigh Waves in the 1755 Lisbon Earthquake
Moderate-magnitude shallow earthquakes in the Atlantic Ocean, hundreds of kilometres southwest of Lisbon, can generate efficient suboceanic Rayleigh waves (SRW) that are well recorded in Portugal. Here we compare moderate-size earthquakes recorded by seismic stations in Portugal with the Tyrrhenian Sea earthquakes recorded in peninsular Italy where SRW were recently observed. In spite of a different behaviour of high frequencies due to the different tectonic setting of the two areas, similar results are found in the intermediate-period range, suggesting that this effect, if extrapolated to a magnitude larger than 8, could be devastating at regional distance in terms of ground motion amplitude and duration. Through 1D models, we explore the hypothesis that the high level of destruction and the long duration of shaking felt during the Great 1755 Lisbon earthquake were caused by SRW. In this preliminary study, we check the role of critical model parameters. We find that duration and amplitude are largest when the average thickness of the water layer is 2 km and shear-wave velocity of the ocean floor is close to the speed of sound in the water. Both conditions are realistic for a source in the Atlantic Ocean, few hundreds of kilometres southwest of Lisbon. Moreover, the propagation of SRW at regional distances accounts for durations of more than ten minutes as the effect of a single large earthquake
Reply to comment by Giuliano F. Panza on “Rarely observed short-period (5–10 s) suboceanic Rayleigh waves propagating across the Tyrrhenian Sea”
We thank Giuliano F. Panza for the interest demonstrated
in our study and for having pointed out the error in
Figure 3 of Rovelli et al. [2004, hereinafter referred to as
R2004GRL]. In his comment, Panza writes that a similar
phenomenon was already reported by him in an old paper.
This statement is not correct and we feel that probably we
did not emphasized enough the innovative character of
R2004GRL. His comment gives us the opportunity of better
explaining that the phenomenon we observe in the Tyrrhenian
Sea is different from those studied by Panza and
coauthors.PublishedL10310JCR Journalreserve