1,720,990 research outputs found
Sea caves and coastal karst scenery along the maltese coasts: The case study of blue grotto
No full textTens of sea caves and other coastal karst landforms are to be found along the limestone coast of the Maltese Islands. Most of the sea caves develop around the present-day sea level, such as Blue Grotto, which is one of the widest and most spectacular sea cave on the islands. The Blue Grotto karst system is composed by partially submerged chambers, sea arches, gorges and small-scale landforms, such as coastal notches, and speleothems. Such landforms developed at the northwestern side of Wied Babu, in a half a kilometer wide bay near Żurrieq. This chapter presents the results of a detailed geomorphological survey of these coastal and karst landforms and discusses the origin and development of the studied landforms. The close relation with the sea level suggests that the system is partly related to former enlargement of dissolutionally widened karst voids and partly related to present-day marine processes, such as waves, and subaerial processes, including rock collapse. Although most of the species recorded from the environs of Filfla are common elsewhere around the Maltese Islands, in general, the recorded biotopes exhibit high species richness values, which is indicative of a low degree of anthropogenic pressure being exerted on the site
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
Impact of the October 2018 storm Vaia on coastal boulders in the northern Adriatic Sea
No full textBoulder detachment from the seafloor and subsequent transport and accumulation along rocky coasts is a complex geomorphological process that requires a deep understanding of submarine and onshore environments. This process is especially interesting in semi-enclosed shallow basins characterized by extreme storms, but without a significant tsunami record. Moreover, the response of boulder deposits located close to the coast to severe storms remains, in terms of accurate displacement measurement, limited due to the need to acquire long-term data such as ongoing monitoring datasets and repeated field surveys. We present a multidisciplinary study that includes inland and submarine surveys carried out to monitor and accurately quantify the recent displacement of coastal boulders accumulated on the southernmost coast of the Premantura (Kamenjak) Promontory (Croatia, northern Adriatic Sea). We identified recent boulder movements using unmanned aerial vehicle digital photogrammetry (UAV-DP). Fourteen boulders were moved by the waves generated by a severe storm, named Vaia, which occurred on 29 October 2018. This storm struck Northeast Italy and the Istrian coasts with its full force. We have reproduced the storm-generated waves using unstructured wave model SimulatingWAves Nearshore (SWAN), with a significant wave height of 6.2 m in front of the boulder deposit area. These simulated waves are considered to have a return period of 20 to 30 years. In addition to the aerial survey, an underwater photogrammetric survey was carried out in order to create a three-dimensional (3D) model of the seabed and identify the submarine landforms associated with boulder detachment. The survey highlighted that most of the holes can be considered potholes, while only one detachment shape was identified. The latter is not related to storm Vaia, but to a previous storm. Two boulders are lying on the seabed and the underwater surveys highlighted that these boulders may be beached during future storms. Thus, this is an interesting example of active erosion of the rocky coast in a geologically, geomorphologically, and oceanologically predisposed locality
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
Coastal Flysch instability on the Slovenian coasts: the role of lithology and fracture pattern
No full textThe origin and dynamics of coastal boulders in a semi-enclosed shallow basin: A northern Adriatic case study
No full textThis paper documents the analysis of a coastal boulder deposit that was recently identified along the northern Adriatic coast (Premantura Promontory, Istria, Croatia). Accumulations of large boulders have not previously been reported in the northern Adriatic, which can be viewed as a semi-enclosed basin. A multidisciplinary approach was used to investigate the site including geological and geomorphological surveys, together with the use of an Unmanned Aerial Vehicle (UAV), digital photogrammetric analysis, hydrodynamic modelling and 14C AMS datings. Measurements of boulder position, elevation, size, shape and density were fed into hydrodynamic equations that are used to estimate the minimum storm and tsunami wave height required to enable the accumulation of boulders. Biogenic marine carbonate encrustations observed on 14 boulders suggest the infra- and sublittoral zones as source areas, while for most of the boulders a subaerial origin is hypothesised. The boulder deposit occurs on a flat promontory where the topography, together with the stratified limestone bedding planes and dense joint pattern constitute the predisposing factors for boulder size and detachment. Comparisons between satellite images taken between 2008 and 2017, pictures collected from Internet and a 2012 snorkel survey of the Istrian coast made it possible to highlight the emplacement of a boulder with an estimated weight of 7.65 t during late 2013 or early 2014. The study examines the mechanisms that may be responsible for the detachment and transport of these large limestone rock fragments from the emergent part of the coast and from the sea bed towards inland areas. The results suggest the occurrence of very recent extreme weather conditions as well as multiple historical storm events and exclude a tsunami origin of the boulders
- …
