scholarly journals Imaging continental shelf shallow stratigraphy by using different high-resolution seismic sources: an example from the Calabro-Tyrrhenian margin (Mediterranean Sea)

2010 ◽  
Vol 58 (spe1) ◽  
pp. 55-66 ◽  
Author(s):  
Eleonora Martorelli ◽  
Francesco Latino Chiocci ◽  
Luciana Orlando

High-resolution seismic reflection profiles of the Calabro-Tyrrhenian continental shelf were collected using different seismic sources (Sub-Bottom Profiler, Uniboom, Sparker 0.5-1-4.5 kJ). Noticeable differences and results were obtained both from a geophysical and geological-interpretative point of view. The availability of different sources permitted the definition of the most suitable seismostratigraphic characterization in terms of resolution, penetration and acoustic facies. Very high resolution stratigraphy was defined through profiles produced by different seismic systems used in parallel. This permitted the application of sequence-stratigraphy concepts with the reconstruction of a thick postglacial depositional sequence, formed by a transgressive and a high-stand systems tract. The thickness distribution of postglacial deposits reveals that the main depocenter (55-65 m) is located offshore of the Coastal Range, along a stretch of coast supplied by several small and seasonal streams ("fiumare") and characterized by the lack of a coastal plain. This suggests the greater efficiency of sediment supply and bypass in this area relatively to sectors located offshore of the main rivers. The transgressive systems tract, usually thin or nearly absent, is particularly well developed (up to 33 m) and is composed of up to three parasequences with a retrogradational stacking pattern. The high-stand systems tract, up to 30 m thick, is made up of two parasequences and has a quite regular geometry and acoustic facies.

1988 ◽  
Vol 25 (6) ◽  
pp. 853-865 ◽  
Author(s):  
Denis Bonifay ◽  
David J. W. Piper

Seismic reflection profiles from the continental slope off St. Pierre Bank show a distinctive acoustic facies characterized by incoherent reflections (unit E) overlain by 5–20 m of stratified sediments (units D–A). Cores from unit E include poorly sorted silty diamict, locally overconsolidated and including in places some foraminifera. Stratified sediments also occur in places in this facies.The overlying sediments of units D–A, except for the topmost metre of unit A, have a foraminiferal fauna dominated by Elphidium excavatum forma clavata and Cassidulina reniforme, which has been interpreted elsewhere as indicating ice-margin sedimentation. The sediments contain turbidites and rare ice-rafted detritus, and are bioturbated. Accelerometer mass spectrometer radiocarbon dating of shells from the stratified sediments yielded dates between 3.3 and 11.8 ka. Facies E, the top of which has an extrapolated age of 11.5–12.0 ka, is interpreted as slumped morainal diamict and proglacial sediment resulting from a late Wisconsinan ice surge through Halibut Channel. Low basal shear stresses in this thin ice surge left little record in the mud-accumulating basins of the continental shelf.


2021 ◽  
pp. 229-236
Author(s):  
E. V. Tolkachenko

The article discusses the issues of determining the legal status of the islands and the continental shelf, the delimitation of sea spaces on the example of the dispute between Ukraine and Romania over the Zmiyiny Island. Although in the frameworks of this issue the line has been already drawn, it is still relevant and interesting from the point of view of its solution, the legal status of the island, as well as legal, organizational and environmental consequences. The definition of the concepts “island” and “continental shelf” in the international law, as well as related to this the establishment of the legal status of the Zmiyiny Island was analyzed. The organizational and legal foundations in order to regulate the usage of the continental shelf and the island according to the environmental legislation of Ukraine were investigated. The decision of the International Court of Justice regarding the dispute between Ukraine and Romania over the Zmiyiny Island, its legal, organizational and environmental consequences was examined. While the research the following conclusions were made: there are gaps in the international law concerning the status of the island and the establishment around it of the certain and clearly delineated maritime spaces, the geographical features of the islands are not taken into account, etc. Currently the national legislation does not consolidate the definition of the concept of the “continental shelf”. And even if we take into account that the UN Convention on the Law of the Sea is a part of the national legislation, its norms are quite general. There is a need to consolidate special norms of usage of the space under consideration (in particular, in Ukraine) in order to avoid similar precedents in the future, because presently the disputed territories and objects unfortunately already exist in our country. As the research showed, this dispute had not only economic consequences – the loss of the continental shelf around the island, financial losses during its surface development, environmental consequences – a negative impact on the environment of the Zmiyiny Island, which is important for the migrating birds, thereby violating the obligations associated to the entry of the island into the register of European territories important for the protection of the birds (IBA), etc. It should be noted that now the Zmiyiny Island could be used for the tourist purposes, but only as an object of the green (ecological) tourism, which has a unique ecosystem that requires a special protection.


Author(s):  
V. Castano ◽  
W. Krakow

In non-UHV microscope environments atomic surface structure has been observed for flat-on for various orientations of Au thin films and edge-on for columns of atoms in small particles. The problem of oxidation of surfaces has only recently been reported from the point of view of high resolution microscopy revealing surface reconstructions for the Ag2O system. A natural extension of these initial oxidation studies is to explore other materials areas which are technologically more significant such as that of Cu2O, which will now be described.


Author(s):  
Y. Harada ◽  
K. Tsuno ◽  
Y. Arai

Magnetic objective lenses, from the point of view of pole piece geometry, can he roughly classified into two types, viz., symmetrical and asymmetrical. In the case of the former, the optical properties have been calculated by several authors1-3) and the results would appear to suggest that, in order to reduce the spherical and chromatic aberration coefficients, Cs and Cc, it is necessary to decrease the half-width value of the axial field distribution and to increase the peak flux density. The expressions for either minimum Cs or minimum Cc were presented in the form of ‘universal’ curves by Mulvey and Wallington4).


2019 ◽  
Vol 30 (2) ◽  
pp. 109-122
Author(s):  
Aleksandar Bulajić ◽  
Miomir Despotović ◽  
Thomas Lachmann

Abstract. The article discusses the emergence of a functional literacy construct and the rediscovery of illiteracy in industrialized countries during the second half of the 20th century. It offers a short explanation of how the construct evolved over time. In addition, it explores how functional (il)literacy is conceived differently by research discourses of cognitive and neural studies, on the one hand, and by prescriptive and normative international policy documents and adult education, on the other hand. Furthermore, it analyses how literacy skills surveys such as the Level One Study (leo.) or the PIAAC may help to bridge the gap between cognitive and more practical and educational approaches to literacy, the goal being to place the functional illiteracy (FI) construct within its existing scale levels. It also sheds more light on the way in which FI can be perceived in terms of different cognitive processes and underlying components of reading. By building on the previous work of other authors and previous definitions, the article brings together different views of FI and offers a perspective for a needed operational definition of the concept, which would be an appropriate reference point for future educational, political, and scientific utilization.


2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Wilson Otto Gomes Batista ◽  
Alexandre Gomes De Carvalho

Contrast-detail (C-D) curves are useful in evaluating the radiographic image quality in a global way. The objective of the present study was to obtain the C-D curves and the inverse image quality figure. Both of these parameters were used as an evaluation tool for abdominal and chest imaging protocols. The C-D curves were obtained with the phantom CDRAD 2.0 in computerized radiography and the direct radiography systems (including portable devices). The protocols were 90 and 102 kV in the range of 2 to 20 mAs for the chest and 80 kV in the range of 10 to 80 mAs for the abdomen. The incident air kerma values were evaluated with a solid state sensor. The analysis of these C-D curves help to identify which technique would allow a lower value of the entrance surface air kerma, Ke, while maintaining the image quality from the point of view of C-D detectability. The results showed that the inverse image quality figure, IQFinv, varied little throughout the range of mAs, while the value of Ke varied linearly directly with the mAs values. Also, the complete analysis of the curves indicated that there was an increase in the definition of the details with increasing mAs. It can be concluded that, in the transition phase for the use of the new receptors, it is necessary to evaluate and adjust the practised protocols to ensure, at a minimum, the same levels of the image quality, taking into account the aspects of the radiation protection of the patient.


Author(s):  
Olena Karpenko ◽  
Tetiana Stoianova

The article is devoted to the study of personal names from a cognitive point of view. The study is based on the cognitive concept that speech actually exists not in the speech, not in linguistic writings and dictionaries, but in consciousness, in the mental lexicon, in the language of the brain. The conditions for identifying personal names can encompass not only the context, encyclopedias, and reference books, but also the sound form of the word. In the communicative process, during a free associative experiment, which included a name and a recipient’s mental lexicon. The recipient was assigned a task to quickly give some association to the name. The aggregate of a certain number of reactions of different recipients forms the associative field of a proper name. The associative experiment creates the best conditions for identifying the lexeme. The definition of a monosemantic personal name primarily includes the search of what it denotes, while during the process of identifying a polysemantic personal name recipients tend have different reactions. Scientific value is posed by the effect of the choice of letters for the name, sound symbolism, etc. The following belong to the generalized forms of identification: usage of a hyperonym; synonyms and periphrases or simple descriptions; associations denoting the whole (name stimulus) by reference to its part (associatives); cognitive structures such as “stimulus — association” and “whole (stimulus) — part (associative)”; lack of adjacency; mysterious associations. The topicality of the study is determined by its perspective to identify the directions of associative identification of proper names, which is one of the branches of cognitive onomastics. The purpose of the study is to identify, review, and highlight the directions of associative identification of proper names; the object of the research is the names in their entirety and variety; its subject is the existence of names in the mental lexicon, which determines the need for singling out the directions for the associative identification of the personal names.


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