Contributions from an integrated analysis of geochemical and geophysical parameters to the study of failed eruptions at Mt. Etna

Continuous monitoring at Mt. Etna volcano usually unveils remarkable changes in geophisycal and geochemical parameters before the onset of volcanic activity. However, signals of apparent impending volcanic unrest are sometimes recorded without being followed by any eruption. Based on data acquired by the permanent monitoring networks run by INGV, we present cases of "failed eruption" at Mt. Etna from februery to April 2007

An unloading foam model to constrain Etna’s 11–13 January 2011 lava fountaining episode

The 11–13 January 2011 eruptive episode at Etna volcano occurred after several months of increasing ash emissions from the summit craters, and was heralded by increasing SO2 output, which peaked at ∼5000 megagrams/day several hours before the start of the eruptive activity. The eruptive episode began with a phase of Strombolian activity from a pit crater on the eastern flank of the SE‐Crater. Explosions became more intense with time and eventually became transitional between Strombolian and fountaining, before moving into a lava fountaining phase. Fountaining was accompanied by lava output from the lower rim of the pit crater. Emplacement of the resulting lava flow field, as well as associated lava fountain‐ and Strombolian‐phases, was tracked using a remote sensing network comprising both thermal and visible cameras. Thermal surveys completed once the eruptive episode had ended also allowed us to reconstruct the emplacement of the lava flow field. Using a high temporal resolution geostationary satellite data we were also able to construct a detailed record of the heat flux during the fountain‐fed flow phase and its subsequent cooling. The dense rock volume of erupted lava obtained from the satellite data was 1.2 × 106 m3; this was emplaced over a period of about 6 h to give a mean output rate of ∼55 m3 s−1. By comparison, geologic data allowed us to estimate dense rock volumes of ∼0.85 × 106 m3 for the pyroclastics erupted during the lava fountain phase, and 0.84–1.7 × 106 m3 for lavas erupted during the effusive phase, resulting in a total erupted dense rock volume of 1.7–2.5 × 106 m3 and a mean output rate of 78–117 m3 s−1. The sequence of events and quantitative results presented here shed light on the shallow feeding system of the volcano

A multidimensional account of democratic legitimacy: how to make robust decisions in a non-idealized deliberative context

This paper analyses the possibility of granting legitimacy to democratic decisionmaking procedures in a context of deep pluralism. We defend a multidimensional account according to which a legitimate system needs to grant, on the one hand, that citizens should be included on an equal footing and acknowledged as reflexive political agents rather than mere beneficiaries of policies, and, on the other hand, that their decisions have an epistemic quality. While Estlund\u2019s account of imperfect epistemic proceduralism might seem to embody a dualistic conception of democratic legitimacy, we point out that it is not able to recognize citizens as reflexive political agents and is grounded in an idealized model of the circumstances of deliberation. To overcome these ambiguities, we develop an account of democratic legitimacy according to which disagreement is the proper expression of citizens\u2019 reflexive agency and the attribution of epistemic authority does not stem from a major expertise or specific ability, but it comes through the public confrontation among disagreeing agents. Consequently, the epistemic value of deliberation should be derived from the reasons-giving process rather than from the reference to the alleged quality of its outcomes. In this way, we demonstrate the validity of the multidimensional perspective of legitimacy, yet abstain from introducing any outcome-oriented criterion. Finally, we argue that this account of legitimacy is well suited for modeling deliberative democracy as a decision-making procedure that respects the agency of every citizen and grants her opportunity to influence public choices

"Failed” eruptions revealed by integrated analysis of gas emission and volcanic tremor data at Mt. Etna, (Italy)

Mt Etna in Sicily is among the most intensely monitored and studied volcanoes on Earth due to its very frequent activity, and its location in a densely populated area. Through a sophisticated monitoring system run by the Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Etneo (INGV-OE), scientists are gaining every day and in real time a picture of the state of volcanic activity of Etna. During the spring of 2007, various episodes of paroxysmal activity occurred at the South-East Crater, one of the four summit craters of Mt Etna. These episodes were always associated with a sharp increase in the amplitude of the volcanic tremor as well as changes in the spectral characteristics of this signal. Eruptive activity ranged from strong Strombolian explosions to lava fountains coupled with copious emission of lava flows and tephra. During inter-eruptive periods, recurrent seismic unrest episodes were observed in form of both temporary enhancements of the volcanic tremor amplitude as well as changes of spectral characteristics. These changes often triggered the automatic alert systems in the operation room of the INGV-OE, even though not being followed by manifest eruptive activity at the surface. The influence of man-made or meteorologically induced noise could be ruled out as a cause for the alarms. We therefore performed a multiparametric analysis of these inter-eruptive periods by integrating seismic volcanic tremor, in-soil radon, plume SO2 flux and thermal data, discussing the potential volcano-dependent source of these episodes. Short-term changes were investigated applying pattern classification, in particular Kohonen Maps and fuzzy clustering, simultaneously on volcanic tremor, radon and ambient parameters (pressure and temperature). The well established SO2 flux and thermal radiation data were used as the “smoking gun”, for certifying that the observed changes in seismic and in radon data can be considered as volcanogenic. Our results unveil ‘failed’ eruptions between February and April 2007 that are explained as ascending magma batches, which triggered repeated episodes of gas pulses and rock fracturing, but that failed to reach the surface

Minería de texto y deep learning aplicados a determinar la pertenencia de las consultas realizadas a un metabuscador a cada área temática dentro de las ciencias de la computación

Al trabajar en un metabuscador que permita identificar cuáles son las mejores recomendaciones en un área temática específicas según las consultas ingresadas por el usuario existen diversos problemas que abordar. En el presente trabajo se realiza el análisis de la pertenencia de una consulta escrita en lenguaje coloquial a una o varias áreas de temáticas dentro de las ciencias de la computación. Para lo cual se podrán tomar varios criterios y se realiza un relevamiento del estado de arte específico con la finalidad de determinar las mejores estrategias tanto para el tratamiento del texto como para la clasificación de los artículos. En este trabajo se presenta el relevamiento realizado para abordar y resolver esta problemática.Eje: Agentes y Sistemas Inteligentes.Red de Universidades con Carreras en Informátic

Estrategias de desambiguacion de perfiles y similitud temática para un metabuscador de las ciencias de la computación

Un metabuscador académico para el área de las Ciencias de la Computación requiere gestionar los resultados de sus búsquedas y brindar sus servicios adecuadamente. En particular, los servicios de recomendación y gestión de resultados requieren el abordaje de problemas de desambiguación de las entidades que recupera, así como recomendación de autores. En este trabajo se presentan las líneas de investigación relacionadas con la evaluación de estrategias para la desambiguación de autores, junto con una línea relacionada con la recomendación de autores en base a los contenidos temáticos de sus perfiles. Los resultados obtenidos en la evaluación de una estrategia de desambiguación demuestran que se pueden obtener un desempeño equivalente a la referencia. Asimismo, se describe un conjunto de datos en desarrollo para la evaluación de la recomendación de perfiles de autores en base a contenidos temáticos para el área de las Ciencias de la Computación.Eje: Base de Datos y Minería de Datos.Red de Universidades con Carreras en Informátic