18 research outputs found

    Analyzing spatial data from twitter during a disaster

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    Social media can be an invaluable help in a mass emergency, but the information handling can be challenging. One major concern is identifying posts related to the area, or pinning them on a map. This exploratory study analyzes the spatial data coming with tweets during two natural disasters, an earthquake and a hurricane. Geo-tagged tweets confirm to be a small fraction of all tweets and disasters within a limited region appear to be a niche topic in the whole stream. The results can help researchers and practitioners in the design of tools to identify these messages

    Analysis of Ordinary Buildings on the Island of Ischia (Italy) for a Seismic Impact Assessment

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    Ischia is a quiescent volcanic complex, characterized by several periods of activity, also of explosive typology. Each year, seismic stations detect few low-energy events, although in the past severe earthquakes occurred, causing extensive damage. The last significant seismic event, with a magnitude of 3.91, occurred on 21st August 2017, again in the municipality of Casamicciola. The hazard constituted by seismic phenomena is compounded by a high exposed value, in terms of population and buildings. From 1861 to today, the resident population has increased considerably, from 23,511 to 62,831 units, to which are added 4 million tourists a year. The high risk of the Ischia territory highlights the need to bring the sustainable planning at the centre of the debate, considering the vulnerability of the area. In this perspective, an application aimed at assessing the seismic impact scenario induced by a single seismic event is illustrated below. The aim is to show a methodological approach able to quantify the resources necessary for emergency planning and organization of operational intervention

    The 21 August 2017 Ischia (Italy) Earthquake Source Model Inferred From Seismological, GPS, and DInSAR Measurements

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    The causative source of the first damaging earthquake instrumentally recorded in the Island of Ischia, occurred on 21 August 2017, has been studied through a multiparametric geophysical approach. In order to investigate the source geometry and kinematics we exploit seismological, Global Positioning System, and Sentinel-1 and COSMO-SkyMed differential interferometric synthetic aperture radar coseismic measurements. Our results indicate that the retrieved solutions from the geodetic data modeling and the seismological data are plausible; in particular, the best fit solution consists of an E-W striking, south dipping normal fault, with its center located at a depth of 800 m. Moreover, the retrieved causative fault is consistent with the rheological stratification of the crust in this zone. This study allows us to improve the knowledge of the volcano-tectonic processes occurring on the Island, which is crucial for a better assessment of the seismic risk in the area.Published2193-22023T. Sorgente sismicaJCR Journa

    The microbiota as a candidate biomarker for SPA pools and SPA thermal spring stability after seismic events.

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    Worldwide, the location of thermal springs overlaps seismic areas, and the higher occurrence of earthquakes may impact on water stability and safety. The hydrogeological perturbations pose environmental and public health risks that can be monitored by well-established chemical, physical and biological parameters. Specific health concerns involve the exposure of the population to the medical or wellness uses of SPA thermal waters, e.g. in respiratory or hydropinic treatments as well as during rehabilitative or recreational activities in pools. Since SPA waters are characterized by their own microbiota, we analysed by 16S amplicon sequencing the dynamics of water microbial communities after the August 2017 Ischia island earthquake. For the first time, we report the impact of a seismic event on a thermal spring water, whose microbiota was deeply characterized before and immediately after the natural disaster. The biodiversity stability of the water underwent a dramatic disturbance following the earthquake, as summarized by a Shannon index moving from 1.300 during May 2016-July 2017, up to 1.600 during the first 20–70 h after the event and slightly slowing down to 1.500 after 30 days and to 1.400 after 6 months. Microbiota analysis showed a sudden reduction of the relative abundance of autochthone thermophilic species within the first 20 h and a parallel increase of other thermophilic species as well as of ectopic bacteria from soil, sediments, sea, freshwater and wastewaters. Cultivable mesophilic bacteria were observed only in the first 20 h sample (7 × 103/L), even if the presence of faecal contamination traces was detected by Real Time PCR also up to 70 h after the disaster. OTUs analysis of putative metabolic functions showed several changes between pre and post event, such as in the distribution of Sulphur metabolizing and Carbon fixation species. The restoration of the original pattern followed a slow trend, requiring over six months. The observed results confirm the impact of the earthquake on the microbiota structure of the underground thermal spring water, suggesting further perspectives for monitoring water stability and safety issues by a metagenomic approach. Keywords: Earthquake, SPA thermal water, Microbial stability, Biodiversity, Hygien

    In-plane Behaviour of an Iron-Framed Masonry Façade: Comparison between Different Modelling Strategies

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    The ‘baraccato’ system is a construction technique with genius earthquake resilient features, used for the reconstruction of the historical city centres in the South of Italy after the catastrophic events occurred in the 18th-19th centuries. A very interesting example of such a building typology is represented by the Church of Santa Maria Maddalena, located in the municipality of Casamicciola Terme of the Ischia Island and built in 1896, after the catastrophic earthquake of 1883. The church is characterized by a mixed ‘baraccato’ system mainly made of yellow tuff block masonry walls strengthened by iron profiles or wooden elements. The reduced damage suffered by the church after the seismic event of 21st August 2017 evidenced the good behaviour of such a mixed structural system, especially into avoiding out-of-plane mechanisms. The presence of the iron-framed system is even more challenging in the definition of the modelling strategies for the structural analysis of the church. Thus, the choice of an appropriate numerical strategy to be used for nonlinear simulation should be properly investigated since the interaction between the frame elements and the elements representing the masonry walls has to be considered. As a first step of the structural analysis of the whole church, the in-plane behaviour of the main façade of the Church of Santa Maria Maddalena is analysed in this paper, with the aim to evaluate the efficacy of different modelling strategies. In particular, the study considers different models according to Finite and Discrete Element strategies available within DIANA FEA [1] and 3DMacro [2] software, respectively. Non-linear static analyses are carried out by means of both software and the obtained results are compared and discussed with the aim of extending them to the study of the whole church

    Earthquake risk scenarios in urban areas: a review with applications to the Ciutat Vella district in Barcelona, Spain

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    This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Architectural Heritage on 2018, available online at: http://www.tandfonline.com/10.1080/15583058.2018.1503367.The vulnerability index and capacity spectrum-based methods used to assess the expected physical damage in dwellings are revisited, and their main advantages and shortcomings are analyzed and discussed. Then, a vulnerability index-based method is used to assess the expected damage in the oldest district of Barcelona, Spain. The risk analysis is performed for earthquake scenarios defined by macroseismic intensities of V, V-VI, VI, VI-VII, and VII to design seismic emergency plans. According to the Spanish Seismic Code, the basic peak ground acceleration for a 475-year return period is 0.04 g, which corresponds to an intensity of VI. Thus, the expected physical damage is quantified and its impact on population and other quantities, such as debris and economic cost, are studied. In spite of the low-to-moderate seismic hazard in Barcelona, the results show that the risk is high, due to the high exposure and vulnerability of the built environment.Peer ReviewedPostprint (author's final draft

    Dislocation and Materiality

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    Dislocation, and Materiality is the culmination my three years of research into artists and theorists, whose work provided me with a clearer direction in my practice as a painter. My research has enabled me to become more aware of the reasons for my current approach to painting that includes: relying on my physical energy, the inherent properties in the material/paint, defining space, memory of place that suggests urban landscape and its inhabitants. The theories of Georges Bataille on the mark, François Jullien on the Chinese concept of lifeforce, and Theodor Adorno on how dissonance is central to artistic and aesthetic process have fed the development of my creative practice. The key artists I researched –Anselm Kiefer, Julie Mehretu, Fabienne Verdier, Mark Bradford, and Phyllida Barlow – provided me with new concepts to introduce in my own work. Mehretu's paintings supplied me with the solution for incorporating political content by means of suggestive titles and expressive marking over imagery. Kiefer's rich assortment of media led me to understand how materials contribute to the meaning of a work. Verdier's gesture and physical energy encouraged me to let go of control and embrace expressionistic paint application. How Mark Bradford uses found brochures and posters from his neighbourhood, transforming them into material for his work gave me the insight that meaning can be in the actual materials. Phyllida Barlow's dynamic works made me consider how the different kinds of marks I create carry vitality and ideas communicated by the material properties of the paint

    The Canton Telephone: Vol. 1, No. 35 - September 12, 1883

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    https://digitalmaine.com/canton_telephone/1046/thumbnail.jp

    Zarathustra's Blessed Isles: Before and After Great Politics

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