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Subduction hints from the northeastern Mediterranean Sea
Get PDFThe eastern Mediterranean is shaped by the interaction between the African, Arabian, and Eurasian plates resulting in a complex tectonic framework. The Hellenic subduction is well documented and studied but, the northeast corner of the eastern Mediterranean Sea remains enigmatic. It is a tectonically active region where different plate boundary conditions coexist (i.e., oceanic subduction, continental collision, extension, and strike-slip movements). An active and tsunamigenic system has been interpreted west and east of Cyprus by using deep seismic reflection lines. Vintage deep-penetrating seismic reflection profiles of the Mediterranean Sea project (MS project) - acquired during the ’70 - were re-analyzed and merged with a synthesis of available subsurface data from the scientific literature. This study focuses on two transects (MS53 and MS56) that cross the major offshore structures (i.e., Florence Rise, Latakia Ridge, and Kyrenia Ridge) from north to south. The western transect (MS53) shows the Herodotus oceanic crust subducting northward beneath the Eurasian plate. The Florence Rise is the leading edge of the system, and the Antalya Basin is its forearc basin. Close to the Turkish coast, a buried block seems to act as a backstop for the offshore system, and north of it, some out-of-sequence thrusts have been interpreted. The strain is partitioned between the Florence Rise and the Taurides front. The eastern transect (MS56) crosses the Latakia Ridge, i.e., the northern boundary of the Levant Basin, where shortening is greater than in the western area. The seismic line continues northward into the Cyprus – Latakia Basin, crossing the Kyrenia Ridge, and reaching the Turkish coast. On the seismic section, we interpreted the Mesozoic subduction front now hindered by strike-slip movements on the Latakia Ridge. Another prominent transpressive structure is the Kyrenia Ridge, which is interpreted as an active structure with a well-imaged thrust system in front of it. The seismic sections were depth converted to provide a regional geologic model for the northeastern Mediterranean Sea. Active subduction fronts, which are only partially imaged, were structurally modeled and then crosschecked with previous studies to better constrain their geometry. In the northeastern Mediterranean Sea, a plate boundary is buried offshore with active subduction west of Cyprus and mainly transpressional tectonics to the east. A better understanding of its nature and kinematics would be useful to assess the tsunami hazard in this area
Reconstruction and tsunami modeling of a submarine landslide on the Ionian margin of Calabria (Mediterranean sea)
No full textThe Ionian margins of Calabria are affected by repeated sediment failures, recorded by slide scars at seabed and stacked slide deposits. We present a reconstruction of the geometry and dynamics of one of the largest seabed features, the Assi failure on the relatively steep slope off southern Calabria, and use it as input to numerical modeling to evaluate the potential tsunamigenic hazard. The Assi failure is up to 6 km wide and at least 18 km long, and involved the displacement of ca. 2 km3 of sediment, inferred to have taken place within the last 4,000 years in two main phases. The first and larger phase is used as input to the tsunami modeling, on the assumption that the slide moved in a single step as a coherent mass of 1.85 km3, in order to evaluate the most disruptive possible consequences. The results indicate that within 8 minutes, waves just over 1 m in height affect the southern Calabrian coast between Monasterace and Roccella Jonica, where their capacity to cause damage could be amplified in small harbours. This shows that tsunamis represent a hazard for Ionian coastal areas, and calls for accurate monitoring and further study
Late Mesozoic – Cenozoic evolution of the eastern Cyprus offshore
Get PDFThe present‐day tectonic setting of the Eastern Mediterranean Sea results from a long deformation history, characterized by an alternation of extensional and contractional phases: from Mesozoic rifting to Late Cretaceous-present-day compression. This study focused on the tectonic reconstruction of the north-eastern side of the Mediterranean Sea, on a sector located between the Turkish coast and the northern Levantine Basin, using seismic reflection profiles. Previous studies dealt with the recent (Neogene) evolution because they did not have enough depth of investigation to recognize deeper reflections.
We used vintage data such as MS and Strakhov surveys to analyze the deeper part of the area. We interpreted and depth-converted these seismic data, and we developed a sequential restoration to reconstruct the stratigraphic and structural evolution of the study area.
In general, from north to south, we recognize the Cilicia Basin: a piggy-back basin bordered to the south by the offshore continuation of the Kyrenia Range. The Kyrenia Range is a positive flower structure generated during a transpressional phase because of the rotation of the Arabic plate. Southward, a secondary contractional system with an onlapping wedge is present in the area between the Kyrenia Range and another prominent ridge, i.e. the Larnaca Ridge. In the southern part, the same transpressional phase that generated the Kyrenia Range led to a positive inversion of an ancient extensional system, i.e. the Latakia Ridge. Beyond these positive flowers, the Levantine Basin is affected by extensional structures showing weak positive reactivation, including halokinetic features.
In summary, we found that the inherited extensional structures strongly impacted the following contractional ones affecting both their geometry and their kinematics
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
The Origin of Gas Seeps in the Northern Adriatic Sea
Get PDFA multidisciplinary approach has been used for the first time to study the widespread occurrence of hydrocarbon seeps in the northern Adriatic Sea. Geological, geophysical and geochemical analyses were performed to identify and characterize the gas-charged fluids occurring throughout the Plio-Quaternary succession, and to date the shallow gas seeping at three leakage sites. The analysis of CHIRP, morpho-bathymetric, and multichannel seismic data allowed us to identify different types of gas-related features, which occur within the whole Plio-Quaternary succession up to the seafloor and to the water column. Quantitative analyses of CHIRP data were conducted to better define, characterize and quantify the gas occurrence within the uppermost stratigraphic succession. CHIRP data also allowed identifying the gas leakage sites. Three gas seepages areas were sampled with the aim to determine the gas composition and origin. The isotopic analyses revealed that seep gases are microbial in origin, and are primarily composed by methane, mostly formed within relatively laterally persistent Late Pleistocene peat layers, which are widely distributed throughout the northern Adriatic Sea and represent the main source of organic matter feeding the seeping gases
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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