Search results for " Earthquake"
showing 10 items of 81 documents
Characterization of MEMS accelerometer self-noise by means of PSD and Allan Variance analysis
2017
In this paper, we have studied the sources of error of a low-cost 3-axis MEMS accelerometer by means of Power Spectral Density and Allan Variance techniques. These techniques were applied to the signals acquired from ten identical devices to characterize the variability of the sensor produced by the same manufacturer. Our analysis showed as identically produced accelerometer have somehow variable behavior in particular at low frequency. It is therefore of paramount importance before their use in Inertial Navigation or Earthquakes Monitoring System, a complete characterization of each single sensors.
Late Hercynian Plate and Intraplate Processes within Europe
1987
The Hercynian orogenic belt of Europe consists of a central crystalline ridge which is accompanied on both sides by a rather unmetamorphosed foldbelt. It is speculated that the crystalline ridge represents some kind of island arc system underlain by a segment of continental crust. On both sides this island arc system was involved in subduction of oceanic crust, first of the Mideuropean Sea in the North and then of the Paleotethys in the South. When the continental areas to the north and south of the oceanic areas (North America/Northern Europe and Africa) finally got involved in the subduction processes, continent/continent collision took place on both sides of the island arc system. The tw…
Interventi nel palazzo di città di Palermo dopo il sisma del 1823
2019
Founded in 15th century, Palermo’s Town-hall was repeatedly reformed in the following centuries. This contribution, based on an unplished archival document kept at the Municipal Historical Archive in Palermo, focuses on the interventions carried out in the building after 1823 earthquake. This was the occasion for a significant renovation of the interior spaces of the building, in particular, the sequence vestibule, atrium, staircase. Moreover, the document offers interesting information on the tecnichs and materials in use at the beginning of 19th century in Palermo’s building sites.
Traditional vs. sliding-joint masonry infilled frames: Seismic reliability and EAL
2020
Abstract In reinforced concrete (RC) multi-storey buildings, the important role of the seismic interaction of structural frames with masonry infills has been revealed by several earthquakes and investigated by many authors. Recently, several innovative infill solutions have been proposed to mitigate such interaction, which could result in widespread damage in both the masonry and the RC structure and sometimes jeopardize the building stability and the occupants’ safety. One solution consists in the partitioning of the masonry infill into several sub-panels, relatively sliding along specific joints. This paper investigates the seismic assessment of this technological solution in the framewor…
Dilatant plasticity applied to Alpine collision: ductile void growth in the intraplate area beneath the Eifel volcanic field
1998
The Eifel is located in the middle of the European plate far away from any active plate boundary, yet it appears to be a maximum of intraplate tectonic activity. A map of intraplate seismic energy flow shows that the Eifel is linked to the Alpine collisional belt via a narrow seismoactive shear zone. Two parallel Quaternary volcanic zones (the East Eifel Volcanic Zone EEVZ and the West Eifel Volcanic Zone WEVZ) line up with the seismogenic shear zone. Xenoliths ejected from these volcanic lineaments indicate upper mantle shearing by dynamic recrystallization textures and metasomatized chemistry. Important CO2-dominated mantle degassing observed in mineral springs, lakes or dry degassing sug…
Brief communication: Vehicle routing problem and UAV application in the post-earthquake scenario
2017
Abstract. In this paper we simulate a Unmanned Aerial Vehicle's (UAV) recognition after a possible case of diffuse damage after a seismic event in the town of Acireale (Sicily, Italy). Given a set of sites (84 relevant buildings) and the range of the UAV, we are able to find the number of vehicles to employ and the shortest survey path. The problem of finding the shortest survey path is an operational research problem called Vehicle Routing Problem (VRP) whose solution is known to be computationally time-consuming. We used the Simulated Annealing (SA) heuristic that is able to provide stable solutions in relatively short computing time. We also examined the distribution of the cost of the s…
Fluid-triggered earthquake swarms in the Rwenzori region, East African Rift—Evidence for rift initiation
2012
The Rwenzori Mountains are located within the Albertine Rift Valley in western Uganda. To monitor the microseismic activity in the area we have deployed a seismic network of up to 35 stations for a period of about 20 months. The analysis of the recordings revealed several earthquake clusters within a restricted area NE of the mountain block. The clusters form elongated pipes with 1–2 km diameter and vertical extensions of 3–5 km. Most of them are located in 5–16 km depths; however one cluster reaches down to 22 km. Each cluster is composed of a series of single earthquake swarms with durations between a few days and more than a week, interrupted by intervals of inactivity of up to several m…
Ethics of restoration and conservation science: the completion and reuse of the former Mother Church in Santa Margherita di Belice (Sicily) / Ética d…
2016
Restaurare l’architettura significa conservare la sua essenza autentica e le stratificazioni storiche, rispettare il criterio della distinguibilità e attualizzare le funzioni che racchiude. Questo moderno indirizzo culturale e metodologico ha sostanziato il progetto di restauro e di rifunzionalizzazione della ex chiesa madre di Santa Margherita di Belice, in Sicilia, che oggi ospita il “Museo della Memoria”. L’istinto progettuale conservativo si è manifestato fin dalle prime ipotesi d’intervento, quando è stata rigettata la possibilità di riproporre “nuovamente” le masse murarie del monumento, sconquassate da un violento terremoto nel 1968. Si è scelto, infatti, d’attuare un’operazione raff…
(Di)segni contemporanei
2018
Il contributo intende presentare criticamente alcuni interventi di restauro allineati alla più moderna ed evoluta cultura della conservazione. I due interventi sono compiuti in Sicilia sui resti di due monumenti distrutti dal terremoto che danneggiò la vallata del fiume Belice nel 1968. Il tema della reintegrazione della lacuna nei volumi strutturali degli edifici storici è realizzata attraverso il procedimento per "astrazione volumetrica", con esiti sorprendenti e d'elevata qualità conservativa. The contribution intends to critically present some restoration interventions aligned with the most modern and evolved culture of conservation. The two interventions are carried out in Sicily on th…
Time-Frequency Filtering for Seismic Waves Clustering
2014
This paper introduces a new technique for clustering seismic events based on processing, in time-frequency domain, the waveforms recorded by seismographs. The detection of clusters of waveforms is performed by a k-means like algorithm which analyzes, at each iteration, the time-frequency content of the signals in order to optimally remove the non discriminant components which should compromise the grouping of waveforms. This step is followed by the allocation and by the computation of the cluster centroids on the basis of the filtered signals. The effectiveness of the method is shown on a real dataset of seismic waveforms.