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Seismic Activity in the Central Adriatic Offshore of Italy: A Review of the 1987 ML 5 Porto San Giorgio Earthquake
No full textOn 3 July 1987, a seismic sequence, with a mainshock of M(L )5, took place in the offshore Adriatic, close to the coast of Porto San Giorgio (PSG), Italy. We present an accurate relocation of the PSG seismic sequence using a nonlinear probabilistic approach (Lomax et al, 2000). The trade-off between the hypo-central location and the velocity model was exhaustively explored using six different velocity models available for the area provided by previous studies. Through numerous tests performed by relocating the mainshock, we selected the two best velocity models providing two different depths (2.0 and 18.0 km). To resolve this intrinsic ambiguity, we developed a technique that uses the macroseismic intensity field data based on a grid search of the magnitude-depth space. The results show that the mainshock has a depth of 5.7 km and a magnitude (M-L) equal to 5; moreover, the relocated seismic sequence (similar to 30 events) developed in the upper portion of the crust (at a depth less than 15 km), thus activating thrust faults, which is typical of the main geological features that characterize the outer Apennines thrust belt and the Adriatic foreland folds. Because the Adriatic Sea hosts several hydrocarbon (mainly gas) production fields located near active faults, with some of them in the area of this study, analyzing the instrumental seismicity is necessary to better understand the seismicity generated by these seismogenic faults and improve the assessment of the area's seismic hazards
A NEW STUDY OF THE PAST SEISMICITY OF THE CENTRAL ADRIATIC OFFSHORE (ITALY): THE 1987 PORTO SAN GIORGIO SEISMIC SEQUENCE
No full textMethodologies for environmental risks assessment related to the exploitation of energy geo-resources
Full text link2019 - 2020The increasing exploitation of geo-energy resources to satisfy the needs of the world's
population has also led to a focus on the risks associated with this type of human activity.
It is in this context that this thesis is to be carried out with the purpose to study TechNa
(Technological Hazard Triggering Natural Disaster) and NaTech (Natural Hazard
Triggering Technological Disaster) events. The natural phenomenon that is a consequence
of an industrial activity or acts as a hazard for the industrial accident is considered to be an
earthquake. The entire thesis, carried out following a multidisciplinary approach, aims to
provide a contribution to the development of methodologies for the assessment of
environmental risks potentially related to the technological activities of geo-resources
exploitation.
Three case studies and different specific methodologies are considered to explore a broad
spectrum of analyses, i.e., the seismic characterization of an area, the statistical correlation
between the industrial and seismic activity, and finally a multi-hazard risk assessment.
The TechNa event considered is the induced seismicity that is studied in the offshore area
of Porto San Giorgio (Italy) and for the Cooper Basin geothermal site (Australia). In the first
case, a probabilistic approach (Lomax et al., 2000) is used to relocate the 1987 Porto San
Giorgio seismic sequence, which occurred in the Adriatic offshore near the Santa Maria a
Mare hydrocarbon field. The ambiguity on the mainshock depth, already known in the
literature, is solved by developing a technique that uses the macroseismic intensity field
data based on a grid-search of the magnitude-depth space. The results show that the seismic
sequence (about 30 events) developed in the first 15 km of the crust activating thrust faults
and the mainshock has depth of 5.7 km and local magnitude equal to 5. Subsequently, to
investigate whether there is a relationship between anthropogenic activity and seismicity, a
statistical correlation analysis is carried out using the binomial and Mann-Whitney tests. It
provides statistically significant values in correspondence with the 1987 Porto San Giorgio
seismic sequence.
The second study on induced seismicity carried out in this thesis concerns the
unconventional geothermal site of Cooper Basin. Unconventional techniques involve
creating fractures for the circulation of fluids, but sometimes they can reach pre-existing
faults by undesirable pathways, triggering strong earthquakes. In this work the relationship
between technological parameters and the potential for seismicity to build undesirable
pathways for fluid migration is investigated through a modern methodology (Lasocki &
Orlecka-Sikora, 2020). ... [edited by Author]XXXIII cicl
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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