1,720,964 research outputs found
Combined GPR and seismic refraction tomography to study the subsoil in the Cathedral of S. Giorgio Ragusa- Ibla (Sicily)
No full textIn this work, we show GPR surveys combined with a series of seismic refraction tomographies to study the subsoil in the Cathedral of S. Giorgio in Ragusa Ibla (Sicily). The church stands on a high structural level characterized by a carbonate formation, consisting of a calcarenite-marly succession. Built in the 18th century, where previously stood the church of San Nicola, the new building probably hosts, under the present flooring, several tombs of different ages and probable remains of the oldest previous church. The combination of the two geophysical methods here proposed allows us to highlight the potential of each technique and how they perfectly support the reconstruction of the subsoil of the church with different details on archaeological and geological/structural buried structures
Extended Tromograph Surveys for a Full Experimental Characterisation of the San Giorgio Cathedral in Ragusa (Italy)
Full text linkGeophysical surveys are widely used to reconstruct subsoil seismo-stratigraphic structures with a non-invasive approach. In this study the geophysical surveys were carried out with the aim to characterise the San Giorgio Cathedral in Ragusa (Italy) and the area on which it is built from a dynamic point of view. A 3D subsoil model was realised through the integration of two active (i.e., seismic tomography and multichannel analysis of surface waves) and one passive seismic technique (horizontal to vertical spatial ratio). The instrumentation used for the latter method consists of a tromograph (Tromino®), which is also employed for the characterisation of the building, focusing on the façade and the dome, by means of an ambient vibration test, processed through the standard spectral ratio and frequency domain decomposition methods. Integration of the 3D model, showing the distribution of areas with different physicomechanical characteristics, enables identifying anomalies that are likely attributable to the remains of the ancient Byzantine church of San Nicola. Four lower modes mainly involving the two investigated macroelements are identified. The experimental results outline the advantages of the use of the tromograph both for soil and structural characterisation, especially for massive masonry buildings located in areas with high seismic hazard
Proposal of a geomorphosite for a small glacial valley on the northeastern flank of the Mount Etna volcano (Sicily)
No full textMount Etna is the largest active volcano of Europe and the highest mountain (about 3,330 m a.s.l.) of peninsular
and insular Italy; moreover, during the Last Glacial Maximum (LGM, 25,000 ÷ 14,000 years BP) it was some
hundreds meters higher than today. Since other mountains of the Apennines were covered by glaciers during the
Upper Pleistocene, several authors hypothesized that a glacial cover could have been also present on Mount Etna
during the LGM, being the estimated limit of perpetual snow around 2,500 m a.s.l. at that time and latitude.
We have carried out a morphological survey in a portion of the volcanic edifice where rocks older than the LGM
outcrop. This portion includes Punta Lucia, on the NW slope, and Serra delle Concazze, on the NE slope. Along the
upper part of the northeastern slope of Etna we have found a small valley, about 170 m long, 15 m wide and 7 m
deep, characterized by a clear U-shaped section, that we interpreted to be of glacial origin.
The search for moraine deposits that could be ascribed to the activity of the hypothesized glacier was unsuccessful
so far and is also complicated by the presence of vegetation and recent lava and tephra deposits covering the
volcano flanks. We are aware that this valley should be considered as a possible geomorphosite to guarantee its
preservation and further study.PublishedParis, Franceope
Proposal of a geomorphosite for a small glacial valley on the northeastern flank of the Mount Etna volcano (Sicily)
No full textMount Etna is the largest active volcano of Europe and the highest mountain (about 3,330 m a.s.l.) of peninsular
and insular Italy; moreover, during the Last Glacial Maximum (LGM, 25,000 ÷ 14,000 years BP) it was some
hundreds meters higher than today. Since other mountains of the Apennines were covered by glaciers during the
Upper Pleistocene, several authors hypothesized that a glacial cover could have been also present on Mount Etna
during the LGM, being the estimated limit of perpetual snow around 2,500 m a.s.l. at that time and latitude.
We have carried out a morphological survey in a portion of the volcanic edifice where rocks older than the LGM
outcrop. This portion includes Punta Lucia, on the NW slope, and Serra delle Concazze, on the NE slope. Along the
upper part of the northeastern slope of Etna we have found a small valley, about 170 m long, 15 m wide and 7 m
deep, characterized by a clear U-shaped section, that we interpreted to be of glacial origin.
The search for moraine deposits that could be ascribed to the activity of the hypothesized glacier was unsuccessful
so far and is also complicated by the presence of vegetation and recent lava and tephra deposits covering the
volcano flanks. We are aware that this valley should be considered as a possible geomorphosite to guarantee its
preservation and further study.PublishedParis, Franceope
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
Mud volcano fields in the Mt. Etna area (eastern Sicily)
No full textIn this paper we describe briefly the activity and evolution of four mud volcano fields located in eastern Sicily,
around the Mt. Etna edifice. Three of them, called “Salinelle dei Cappuccini”, “Salinelle del Fiume” and “Salinelle del
Vallone Salato” based on their location, occur on the southewestern flank of Etna, between the Paternò and
Belpasso villages, and are presently active. The fourth one, today extinct, was active on the farest northeastern
sector of Etna, along the Ionian Sea coastline. It was called “Salsa di Fondachello” after the name of the closest
village.
Geologic surveys and well drillings suggest that fluids uprise through pre-existing volcanic necks in the “Salinelle dei
Cappuccini” and “Salinelle del Fiume”, while for the “Salinelle del Vallone Salato” an alternative pathway through a
fault plane is also proposed. The morphologic evolution of the Etnean mud volcano fields depends mainly on the
density of the emitted muds and secondarily on the preexisting ground topography. Chemical analyses revealed
that the water coming out from the mud volcanoes originates from a deep aquifer confined in the carbonatic rocks
of the Etna basement and that the most abundant escaping gas is CO2 of magmatic origin. The “Salsa di Fondachello” first activity is associated with the occurrence of the destructive Val di Noto earthquake,
on January 11th, 1693. It was again active from 1795 to 1832. Its last activity, started in March 1847, came to an end
with the collapse of the mud volcano. Today a weak methane emission is the only evidence of endogenous activity
in this area.PublishedParis Sorbonne Université, Parisope
Mud volcano fields in the Mt. Etna area (eastern Sicily)
No full textIn this paper we describe briefly the activity and evolution of four mud volcano fields located in eastern Sicily,
around the Mt. Etna edifice. Three of them, called “Salinelle dei Cappuccini”, “Salinelle del Fiume” and “Salinelle del
Vallone Salato” based on their location, occur on the southewestern flank of Etna, between the Paternò and
Belpasso villages, and are presently active. The fourth one, today extinct, was active on the farest northeastern
sector of Etna, along the Ionian Sea coastline. It was called “Salsa di Fondachello” after the name of the closest
village.
Geologic surveys and well drillings suggest that fluids uprise through pre-existing volcanic necks in the “Salinelle dei
Cappuccini” and “Salinelle del Fiume”, while for the “Salinelle del Vallone Salato” an alternative pathway through a
fault plane is also proposed. The morphologic evolution of the Etnean mud volcano fields depends mainly on the
density of the emitted muds and secondarily on the preexisting ground topography. Chemical analyses revealed
that the water coming out from the mud volcanoes originates from a deep aquifer confined in the carbonatic rocks
of the Etna basement and that the most abundant escaping gas is CO2 of magmatic origin. The “Salsa di Fondachello” first activity is associated with the occurrence of the destructive Val di Noto earthquake,
on January 11th, 1693. It was again active from 1795 to 1832. Its last activity, started in March 1847, came to an end
with the collapse of the mud volcano. Today a weak methane emission is the only evidence of endogenous activity
in this area.PublishedParis Sorbonne Université, Parisope
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
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