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Stefano Branca - One of the best experts on this subject based on the ideXlab platform.
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constraining age and volume of lava flow invasions of the Alcantara valley etna volcano italy new insights from paleomagnetic dating and 3d magnetic modeling
Journal of Volcanology and Geothermal Research, 2019Co-Authors: Stefano Branca, Francesca Dajello Caracciolo, Arianna Beatrice Malaguti, Fabio SperanzaAbstract:Abstract The Alcantara River marks the northern border of Etna volcano, and along its NE sector, it forms a narrow NW-SE elongated valley that is carved in the Mts. Peloritani sedimentary sequences. The valley has been invaded by several lava flows during the growth of the main bulk of the stratovolcano edifice in the past 60 ky (Ellittico and Mongibello volcanoes). In this paper, we have constrained the age of the main lava flows forming the valley floor and reconstructed the length and volume of the main lava flow that impacted this area through a multidisciplinary approach integrating stratigraphic and aeromagnetic data analysis together with new paleomagnetic and 14C dating. The new age determinations showed that the evolution of the present-day geological and hydrographic setting of the valley was mainly conditioned by a few flank eruptions that occurred in the lower N flank of Etna during the activity of the Mongibello volcano. In particular, between 13.9 and 9.7 ka BP the valley floor was filled by the so-called Alcantara lava flow for its entire length up to the river mouth, reaching a maximum length of about 24 km. Later, two other flank eruptions – producing the so-called Mt. Dolce and Solicchiata lava flows – occurred at 9.1–7.2 and 7.3–7.2 ka BP (respectively), covering the eruptive fissure and the proximal portion of the Alcantara lava field and generated the most recent northward shift of the riverbed. Finally, 3D magnetic modeling allowed us to calculate the total on- and off-shore volume of the Alcantara lava flow as 1 km3, a value comparable to those of the long-lasting historical eruptions of Etna. Conversely, the 24 km length reached by this lava flow is anomalously high when compared to lava flows of the past 15 ky, likely because its emplacement occurred within the valley floor, preventing any possibility of lateral expansion.
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geological and geomorphological evolution of the etna volcano ne flank and relationships between lava flow invasions and erosional processes in the Alcantara valley italy
Geomorphology, 2003Co-Authors: Stefano BrancaAbstract:Abstract In this paper, the interrelationships between volcanic activity and fluvial events in the Alcantara Valley are investigated. Based on the correlation between the stratigraphy of the NE flank of Mt Etna and subsurface data, the geological and geomorphological evolutions of the valley are reconstructed. New 1:10 000 scale geological mapping shows that the bulk of this sector of the volcano is made up of the Ellittico volcano lava flows, though they are widely covered by the products of the eruptive activity of the last 15 ka. The present-day morphological setting of the Alcantara Valley is the result of two main evolutionary phases initiated during the activity of the Ellittico volcano. Only one lava flow invasion of the valley floor occurred in the first phase. This phenomenon was followed by a long period of erosional processes leading to the entrenchment of the drainage pattern and the erosion of the Ellittico lava flow. About 20–25 ka ago, an important change in the frequency of the lava flow invasions into the valley occurred associated with the final stage of the Ellittico volcano activity marking the beginning of the second phase. During this phase, volcanic processes became predominant with respect to other morphogenetic processes in the Alcantara Valley. Lava flows coming from the NE flank of the Ellittico volcano caused a radical modification of the morphological setting of this area, even though only one lava flow emitted by an eruptive fissure located within the valley partially filled the riverbed. During the eruptive activity of the last 15 ka, the complete filling of the Alcantara Valley floor occurred. In particular, between 15 and 7 ka, a lava flow originated from the Mt Moio scoria cone filled the valley floor for a distance of about 9 km. Following a short period of erosion, an eruptive fissure located within the valley generated a 20–21-km-long lava flow that was channelled along the full extent of the Alcantara Valley and stretches for about 3 km offshore in the Ionian sea. In the last 7 ka, lava flows originating from the NE-Rift zone produced only temporary damming of the riverbed without any important contribution to the filling of the Alcantara Valley.
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an example of river pattern evolution produced during the lateral growth of a central polygenic volcano the case of the Alcantara river system mt etna italy
Catena, 2001Co-Authors: Stefano Branca, Vincenzo FerraraAbstract:Abstract Analysis of numerous geognostic soundings and geophysical investigation data, indicates the presence of a wide depression, identifiable as the ancient valley of the Alcantara River, below the northern flank of Mt Etna. Surface and subsurface data were used to reconstruct the complex stratigraphic succession filling the paleo-Alcantara valley, consisting of superimposed lava flows, interlayered with thick lentiform clastic bodies. The evolution of the Alcantara river system was defined with reference to the different phases of growth of Mt Etna. The first correlation between volcanic activity and the drainage system refers to the initial phases of alkaline volcanism (170–100 ka). During this period, the southern watershed of the paleo-Alcantara valley acted as a morphological barrier to the products of the various volcanoes which gradually grew in the sector now occupied by the Valle del Bove. The paleo-Alcantara riverbed was sporadically invaded by lava flows generated by peripheral activity of the central edifice. A radical modification of the hydrographic pattern of the region began about 45–40 ka as a consequence of the growth of the Ellittico volcano, the main eruptive centre of the Etnean edifice. The gradual expansion of this volcano led, over a period between about 30 and 25 ka, to the northward deviation of the paleo-Alcantara riverbed. The consequent erosion of a section of the watershed with the adjacent hydrographic basin of the paleo-S. Paolo river resulted in the capture of the latter. From then on, the hydrographic pattern of the area gradually took on the characteristics it has today. A water circulation system developed within the thick volcanic pile filling the paleo-Alcantara valley, with the formation of an aquifer, which is today one of the most important hydro-structures of the whole volcanic edifice and is, in part, exploited in the eastern side of Sicily.
Fabio Speranza - One of the best experts on this subject based on the ideXlab platform.
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constraining age and volume of lava flow invasions of the Alcantara valley etna volcano italy new insights from paleomagnetic dating and 3d magnetic modeling
Journal of Volcanology and Geothermal Research, 2019Co-Authors: Stefano Branca, Francesca Dajello Caracciolo, Arianna Beatrice Malaguti, Fabio SperanzaAbstract:Abstract The Alcantara River marks the northern border of Etna volcano, and along its NE sector, it forms a narrow NW-SE elongated valley that is carved in the Mts. Peloritani sedimentary sequences. The valley has been invaded by several lava flows during the growth of the main bulk of the stratovolcano edifice in the past 60 ky (Ellittico and Mongibello volcanoes). In this paper, we have constrained the age of the main lava flows forming the valley floor and reconstructed the length and volume of the main lava flow that impacted this area through a multidisciplinary approach integrating stratigraphic and aeromagnetic data analysis together with new paleomagnetic and 14C dating. The new age determinations showed that the evolution of the present-day geological and hydrographic setting of the valley was mainly conditioned by a few flank eruptions that occurred in the lower N flank of Etna during the activity of the Mongibello volcano. In particular, between 13.9 and 9.7 ka BP the valley floor was filled by the so-called Alcantara lava flow for its entire length up to the river mouth, reaching a maximum length of about 24 km. Later, two other flank eruptions – producing the so-called Mt. Dolce and Solicchiata lava flows – occurred at 9.1–7.2 and 7.3–7.2 ka BP (respectively), covering the eruptive fissure and the proximal portion of the Alcantara lava field and generated the most recent northward shift of the riverbed. Finally, 3D magnetic modeling allowed us to calculate the total on- and off-shore volume of the Alcantara lava flow as 1 km3, a value comparable to those of the long-lasting historical eruptions of Etna. Conversely, the 24 km length reached by this lava flow is anomalously high when compared to lava flows of the past 15 ky, likely because its emplacement occurred within the valley floor, preventing any possibility of lateral expansion.
Luis Corral Val - One of the best experts on this subject based on the ideXlab platform.
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la orden de Alcantara durante la edad media segun la documentacion pontificia sus relaciones institucionales con las diocesis el cister otras ordenes militares y la monarquia segunda parte
Hispania Sacra, 2018Co-Authors: Luis Corral ValAbstract:The author offers his first researches about the medieval holdings of the Order of Alcantara that are mainly located in the Vatican Archives, in the Spanish Academy of History and in the National Library in Madrid. In this second part he exposes his historical conclusions—according to the papal documentation—about the relationship of the Order of Alcantara with the episcopal jurisdiction, the Order of Citeaux, others Military Orders and the Monarchy.
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la orden de Alcantara y el papado durante la edad media segun la documentacion pontificia primera parte
Hispania Sacra, 2018Co-Authors: Luis Corral ValAbstract:The author offers his first researches about the medieval holdings of the order of Alcantara that are mainly located in the Vatican Archives, in the Spanish Academy of History and in the National Library in Madrid. In this first part he also exposes his historical conclusions about the origins of the order and its relationship with the papal jurisdiction.
Javier Ortega Alvarez - One of the best experts on this subject based on the ideXlab platform.
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el acceso de don gutierre de sotomayor al maestrazgo de la orden de Alcantara origenes y consecuencias
Espacio Tiempo y Forma. Serie III Historia Medieval, 2011Co-Authors: Javier Ortega AlvarezAbstract:El objetivo de este articulo es profundizar en el estudio de la historia politica de la Orden de Alcantara en el periodo de tiempo que abarca el maestrazgo de don Gutierre de Sotomayor (1432-1453). Para tal fin, nos hemos servido del estudio de su ascension al maestrazgo y de su posterior actuacion en la politica de la convulsa Castilla del segundo cuarto del siglo XV. Para ello, se han utilizado tanto fuentes cronisticas y literarias, como documentacion de archivo. En este sentido, sigue siendo crucial la aportacion que ha supuesto para el desarrollo de las investigaciones la Coleccion Diplomatica Medieval de la Orden de Alcantara, instrumento indispensable para todo aquel que quiera adentrarse en su estudio. The aim of this article is to delve further into the political history of the Order of Alcantara during the period of the Mastership of Gutierre de Sotomayor (1432-1453). We have focused on the study of his ascent to the Mastership and his subsequent participation in the turbulent politics of Castile during the second quarter of the fifteenth century. Our research has made use of chronicle and literary sources, as well as archival records. The contribution of the Coleccion diplomatica medieval de la Orden de Alcantara is invaluable and has become an essential tool for the study of this Order.
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la casa de don gutierre de sotomayor maestre de Alcantara una aproximacion a la prosopografia de la orden de Alcantara
Revista de estudios extremeños, 2010Co-Authors: Javier Ortega AlvarezAbstract:espanolEl objetivo de este articulo es hacer una aproximacion a la prosopografia de la Orden de Alcantara, uno de los aspectos menos estudiados y conocidos de la misma. Para ello nos hemos servido de la figura de don Gutierre de Sotomayor, maestre de la orden durante los anos 1432 a 1453, y, mas concretamente, del analisis de lo que consideramos la �Casa maestral�: concepto, esferas organizativas y planos de parentesco que confluyen en la misma. El resultado de dicho analisis ha sido poner de manifiesto la tupida red de familiares, vasallos y criados que tejio don Gutierre en torno a su persona, consecuencia de la privilegiada posicion que le confirio la dignidad maestral, y avanzar en el estudio prosopografico de la Orden de Alcantara. EnglishThe aim of this article is to do an approach to the prosopography of the Order of Alcantara, one of the aspects least studied and known of the same one. For it, we have made use of the figure of don Gutierre de Sotomayor, master of the order during the year 1432 to 1453 and, more specifically, of the analysis of whatt we considerer to be the �House maestral�: concept, organizational spheres and planes of kinship that come together in the same one. The resulte of the above mentioned analysis has been to reveal the dense network of relatives, vassals and servants that don Gutierre wove concerning his person, consequence of the privileged position that awarded him the dignity maestral, and to advance in the study prosopographic of the Order of Alcantara
Fisch, Gilberto Fernando - One of the best experts on this subject based on the ideXlab platform.
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Sensibilidade de Parametrizações de Camada Limite Planetária do WRF Single-Column Modeling para o Centro de Lançamento de Alcântara
'Universidad Federal de Santa Maria', 2016Co-Authors: Ramos, Diogo Nunes Da Silva, Fernandez, Julio Pablo Reyes, Fisch, Gilberto FernandoAbstract:This study evaluates the planetary boundary layer (PBL) by the sensitivity of different PBL parameterizations for the Alcântara Rocket Launch Center (CLA). The study was produced using two distinct databases, an observational and other numeric. The observational data in surface and radiosondes were of the CHUVA Project for the Alcantara campaign and applied in comparison with the WRF-SCM integrations. These integrations were obtained using five PBL parameterizations (YSU, MYJ, QNSE, MYNN2 and TEMF) in the WRF model (3.7.1) in its version of Single-Column Model (SCM), with initial condition of NCEP’s global model final analysis (FNL/GFS) for 18Z on March 5, 2010, integrating for 30 hours simulations considering spin-up (6 + 24 hours). The overall results do not highlight a standardization of quality of some parameter, despite the MYNN, QNSE and YSU schemes have been closer to the observations at different situations. The PBL height determination was better simulated with YSU and QNSE schemes, and with MYJ to air temperature at 2m. Importantly, the dynamic limitations that an SCM model has also adding the complexity of the Alcântara site and its coastal features of meso and large scale (eg breezes and ITCZ). These problems motivates the future studies, for example, with three-dimensional microscale models such as LES.Este trabalho avalia a camada limite planetária (CLP) através da sensibilidade de diferentes parametrizações de CLP para o Centro de Lançamento de Alcântara (CLA). O estudo foi produzido usando dois diferentes bancos de dados, um observacional e outro numérico. Os dados observados em superfície e por radiossondas foram da campanha de Alcântara do Projeto CHUVA e aplicados na comparação com as integrações numéricas. Estas integrações foram obtidas com cinco diferentes parametrizações de CLP (YSU, MYJ, QNSE, MYNN2 e TEMF) no modelo WRF (3.7.1) em sua versão de Single-Column Model (SCM), inicializadas com as análises finais do modelo global do NCEP (FNL/GFS) de 18Z do dia 05 de março de 2010, para simulações de 30 horas com spin-up (6 + 24 horas). Os resultados gerais não destacam uma padronização de qualidade de alguma parametrização, apesar que os esquemas MYNN, QNSE e YSU foram mais próximos das observações em diferentes momentos. A determinação da altura da CLP foi melhor simulada pelos esquemas de YSU e QNSE, e MYJ para temperatura do ar em 2m. É importante ressaltar as limitações dinâmicas que um modelo SCM possui, adicionando ainda a complexidade do terreno local de Alcântara e suas características costeiras de meso e larga escala (e.g. brisas e ZCIT). Estes problemas motivam a realização de estudos futuros, como a aplicação de modelos tridimensionais de microescala, como o LES
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Perfilador de Vento no Centro de Lançamento de Alcântara: Uma Análise Estatística
'Universidad Federal de Santa Maria', 2016Co-Authors: Custodio, Diogo Machado, Yamasaki Jorge, Quinsan Junior, Hildo Romeo, Fisch, Gilberto FernandoAbstract:Monitoring the atmospheric conditions is one of the main activities in Aerospace Meteorology. During the launch spacecraft operations, measuring the wind at various atmospheric layers is crucial to mission success. In the Alcantara Launch Center operates a Wind Profiler (WP) Vaisala LAP-12000 which provides vertical profiles of wind between 1500 and 6000m of altitude, in layers of 145m, at intervals of 10 minutes. This study conducts a statistical analysis over one year of data obtained with WP by comparison with Vaisala RS92SGP radiosondes (RS). Correlation (ρ) analyses were performed on wind speed and its zonal and meridional components; and mean and standard deviation (σ) of the differences between the zonal and meridional components. The results has shown a strong correlation between the data acquired with both instruments, with ρ > 0,75 and σ 6 3m/s in all performed analyses.O monitoramento das condições atmosféricas é uma das principais atividades da Meteorologia Aeroespacial. Durante operações de lançamento de veículos espaciais, medir o vento em diversas camadas atmosféricas é fundamental para o sucesso da missão. No Centro de Lançamento de Alcântara opera um Perfilador de Vento (WP) Vaisala LAP-12000 que fornece perfis verticais do vento entre 1500 e 6000m de altitude, com medidas em camadas de 145m, realizadas em intervalos de 10 minutos. Este trabalho apresenta uma análise estatística de um ano de dados obtidos com o WP através de comparação com perfis verticais do vento obtidos por radiossondas (RS) Vaisala RS92SGP.Foram feitas análises de correlação (ρ) da velocidade do vento e suas componentes zonal e meridional; média e o desvio padrão (σ) das diferenças entre as componentes zonal e meridional. Observou-se que existe uma forte correlação entre os dados, com ρ >= 0,75 e σ