86 research outputs found

    Assessment of ground-motion amplification in the Fucino Basin (Central Italy) through seismic data

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    The Fucino basin (Central Italy) is one of the largest intermountain alluvial plain in the Appennines range. It has a tectonic origin related to the presence of important systems of faults located in its northern and eastern edges. Some of these faults are still active and capable of generating strong seismic events as the January 13th 1915 Ms 7.0 Avezzano earthquake (about 30000 casualties). Site effects related to the soft soils filling the basin can be very important also taking into account the presence of historical villages located at the edges of the basin and new settlements developed in the area. In this paper we show the preliminary results of a seismic network installed in the Fucino area in order to collect information about site amplification effects and geometry of the basin. A lake occupied the Fucino basin for many thousands of years and it was completely drained at the end of the 19th century. We analyze ambient seismic vibrations and recordings of about 150 local earthquakes mainly related to the seismic sequence of the April 6th 2009 Mw 6.3 L’Aquila event. Moreover the strongest events of L’Aquila sequence were analyzed at the three strong-motion permanent stations operating in the area. Using standard spectral techniques we investigate the variation of resonance frequencies within the basin. The ground motion recorded in the Fucino plain is mainly characterized by strong energy at low-frequencies (f < 1 Hz) affecting both horizontal and vertical components. This is particularly evident for stations deployed in correspondence of very thick deposits of sedimentary filling, where a significant increase of ground-motion amplitude and duration is caused by locally generated surface waves. The amplification at low-frequencies (< 1 Hz) on the horizontal components can reach up a factor of 10 in comparison to nearby stiff sites. However, we found evidences of seismic amplification phenomena also for stiff sites surrounding the basin, including stations of the Italian strong motion network. The independent geological information, the shallow shear-velocity profiles available for the basin can be combined with resonance frequencies of the sites for deriving representative geological sections to be used as base for future numerical 2D-3D modeling of the seismic wave propagation in the basin. Seismic modeling can be important to reduce the seismic hazard in the area

    Assessment of ground-motion amplification in the Fucino Basin (Central Italy) through seismic data

    Get PDF
    The Fucino basin (Central Italy) is one of the largest intermountain alluvial plain in the Appennines range. It has a tectonic origin related to the presence of important systems of faults located in its northern and eastern edges. Some of these faults are still active and capable of generating strong seismic events as the January 13th 1915 Ms 7.0 Avezzano earthquake (about 30000 casualties). Site effects related to the soft soils filling the basin can be very important also taking into account the presence of historical villages located at the edges of the basin and new settlements developed in the area. In this paper we show the preliminary results of a seismic network installed in the Fucino area in order to collect information about site amplification effects and geometry of the basin. A lake occupied the Fucino basin for many thousands of years and it was completely drained at the end of the 19th century. We analyze ambient seismic vibrations and recordings of about 150 local earthquakes mainly related to the seismic sequence of the April 6th 2009 Mw 6.3 L’Aquila event. Moreover the strongest events of L’Aquila sequence were analyzed at the three strong-motion permanent stations operating in the area. Using standard spectral techniques we investigate the variation of resonance frequencies within the basin. The ground motion recorded in the Fucino plain is mainly characterized by strong energy at low-frequencies (f < 1 Hz) affecting both horizontal and vertical components. This is particularly evident for stations deployed in correspondence of very thick deposits of sedimentary filling, where a significant increase of ground-motion amplitude and duration is caused by locally generated surface waves. The amplification at low-frequencies (< 1 Hz) on the horizontal components can reach up a factor of 10 in comparison to nearby stiff sites. However, we found evidences of seismic amplification phenomena also for stiff sites surrounding the basin, including stations of the Italian strong motion network. The independent geological information, the shallow shear-velocity profiles available for the basin can be combined with resonance frequencies of the sites for deriving representative geological sections to be used as base for future numerical 2D-3D modeling of the seismic wave propagation in the basin. Seismic modeling can be important to reduce the seismic hazard in the area

    Effetti di sito della piana del Fucino attraverso lo studio comparato di dati sismici e geologici

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    Il presente lavoro è incentrato nello studio della Piana del Fucino in termini di risposta sismica attraverso metodi di analisi geofisica e correlazioni dei risultati ottenuti con la geologia dell’area. Uno dei terremoti più disastrosi della storia italiana è quello verificatosi nel gennaio del 1915 nella Marsica; ciò testimonia che l’area oggetto di studio è fortemente esposta al rischio sismico. È quindi opportuno provvedere alla riduzione di tale rischio operando in termini di prevenzione. Uno dei metodi consiste nella determinazione dei livelli di scuotimento al suolo attesi in caso di terremoto attraverso lo studio degli effetti di sito. Per fare ciò si sono utilizzati i segnali sismici registrati da una rete di stazioni installate dall’Istituto Nazionale di Geofisica e Vulcanologia per la caratterizzazione geologico-geotecnica dei siti delle stazioni accelerometriche della Rete Accelerometrica Nazionale (richiesto in uno dei Progetti previsti della convenzione tra il Dipartimento della Protezione Civile e l’INGV nel triennio 2007- 2009). L’intervallo temporale coperto dalle stazioni va dall’ottobre 2008 al settembre 2009 ed il dataset selezionato comprende terremoti con Magnitudo superiore a 2 entro un raggio medio di 60 km da Avezzano. In seconda istanza si è proceduto all’installazione di altre stazioni temporanee sempre all’interno della Piana con lo scopo di registrare rumore ambientale a completamento dei dati già in possesso

    Biosynthesis and Cellular Functions of Tartaric Acid in Grapevines

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    Tartaric acid (TA) is an obscure end point to the catabolism of ascorbic acid (Asc). Here, it is proposed as a “specialized primary metabolite”, originating from carbohydrate metabolism but with restricted distribution within the plant kingdom and lack of known function in primary metabolic pathways. Grapes fall into the list of high TA-accumulators, with biosynthesis occurring in both leaf and berry. Very little is known of the TA biosynthetic pathway enzymes in any plant species, although recently some progress has been made in this space. New technologies in grapevine research such as the development of global co-expression network analysis tools and genome-wide association studies, should enable more rapid progress. There is also a lack of information regarding roles for this organic acid in plant metabolism. Therefore this review aims to briefly summarize current knowledge about the key intermediates and enzymes of TA biosynthesis in grapes and the regulation of its precursor, ascorbate, followed by speculative discussion around the potential roles of TA based on current knowledge of Asc metabolism, TA biosynthetic enzymes and other aspects of fruit metabolism

    Results from shallow geophysical investigations in the northwestern sector of the island of Malta

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    We performed geophysical investigations in the northwestern sector of the island of Malta to reconstruct velocity-depth models and provide shear-wave velocity profiles. We have chosen two sites, one located in Rabat (Malta) and another in the Golden Bay area. We used both active (seismic and electrical 2D-tomography, Multichanel Analysis of Surface Waves – MASW) and passive (2D arrays and single-station measurements using ambient noise) geophysical methods. Consistently with previous studies performed in this part of Malta, we have found that both sites are characterised by site resonance in the frequency range 1-2 Hz as an effect of the local lithostratigraphic succession that shows an impedance contrast at about 60-90 m depth. This resonance effect can have important implications on both seismic hazard as well as seismic risk evaluation of the region since the amplified frequency range coincides with the resonance frequencies typical of 5–10 storey buildings which are very diffuse in the Maltese Islands, especially after intense recent urbanization.Published41-484T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa

    NERA project - Deliverable D11.4: Array measurements

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    The aim of this Task is to present the seismological data and some preliminary empirical results related to two deployed specific arrays; (a) the Argostoli seismological array and (b) the Fucino seismological array. Both experiment arrays provided high quality data that along with corresponding geological and geophysical measurements may serve to critical evaluation of site effects and basin effects. In addition, work on modelling of basin effects may be significantly benefited by the observed acquired in both sites. Given that the analyses of the data obtained during the aforementioned experimental arrays will be performed in close link with activity of NERA-JRA3, the following goals are set: To investigate the link between ground motion spatial variability, strains, seismic wavefield and subsurface properties To compare numerical estimates of ground strain with actual measurements To investigate the capability of estimating ground strains from noise correlation studies. In order to organize and accomplish the work according to the initial schedule, several meetings (actual or/and Skype) among the participants took place during the 2nd year of the NERA-JRA1 project. Minutes of these meetings are given in Appendices 1, 2, 3 and 4.Network of European Research Infrastructures for Earthquake Risk Assessment and Mitigation Project, Seventh Framework Programme EC project number: 262330Published4T. Sismologia, geofisica e geologia per l'ingegneria sismic

    GINGER

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    In this paper, we outline the scientific objectives, the experimental layout, and the collaborations envisaged for the GINGER (Gyroscopes IN GEneral Relativity) project. The GINGER project brings together different scientific disciplines aiming at building an array of Ring Laser Gyroscopes (RLGs), exploiting the Sagnac effect, to measure continuously, with sensitivity better than picorad/ s, large bandwidth (ca. 1 kHz), and high dynamic range, the absolute angular rotation rate of the Earth. In the paper, we address the feasibility of the apparatus with respect to the ambitious specifications above, as well as prove how such an apparatus, which will be able to detect strong Earthquakes, very weak geodetic signals, as well as general relativity effects like Lense-Thirring and De Sitter, will help scientific advancements in Theoretical Physics, Geophysics, and Geodesy, among other scientific fields.Comment: 21 pages, 9 figure
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