Probability hazard map for future vent opening at Etna volcano (Sicily, Italy).

We evaluate a probability hazard map for future vent opening at Etna volcano using a data set of flank vents spanning last 4.0 ka

Structural health monitoring and earthquake early warning: preliminary studies for application in eastern Sicily

In this work, the reduction of seismic hazard in eastern Sicily is addressed by both studying the fundamental resonant frequency of strategic buildings through low cost geophysical investigation techniques, and exploring a practical approach to earthquake early warning EEW) system. The fundamental period and the corresponding amplification of some selected strategic buildings has been estimated using ambient vibration and earthquake data. We analyzed the basic dynamic parameters of buildings chosen as target, by using continuous vibration measurements at different floors. The dynamic behavior of structures was evaluated considering both small strains induced by ambient vibrations and larger excitation levels due to the earthquakes occurrence. A practical approach to earthquake early warning in the investigated area was dealt with by using empirical relationships between parameters measured on the initial portion of seismic recordings and related to the earthquake magnitude and peak ground motion. In particular, we performed the first preliminary tests by using empirical relationships calibrated for the considered area and taking into account the geometry of the existing permanent seismic network deployed in the eastern Sicily. The estimated relationships have been used to provide onsite warning around a given seismic station and evaluate the potential damaging effects. The joint of EEW system and geophysical investigation shown in this work may be deemed a useful guide for the future implementation of the in real time seismic monitoring in the region.This work has been supported by the following project: “Attività di sviluppo sperimentale finalizzata alla riduzione del rischio sismico nella Sicilia Orientale” inside the PO-FESR 2007-2013 Sicilia; MED-SUV funded from the European Union Seventh Framework Programme (FP7) under Grant agreement n°308665. This work is sponsored by European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement n° 798480. We are thankful to Salvatore Rapisarda and Danilo Contrafatto to support us in the field work

Seismic amplification effects and soil, to, structure interaction study nearby a fault zone: the Tremestieri fault and Madre Teresa di Calcutta School (Catania)

Results of passive seismic surveys, in terms of both amplification and polarization effects in a section of the Tremestieri Etneo Fault (Sicily Eastern center - Catania) are discussed. For the purpose, velocimetric and accelerometric records of seismic ambient noise were analyzed. The polarization analysis of particle motion was performed and azimuthally dependent resonant frequencies were estimated. Ambient noise data were also used to assess the dynamic properties of a reinforced concrete building, located on the fault zone. The fundamental modes have been estimated through ambient noise recordings acquired by three-directional accelerometers, installed at the highest accessible floor and outside the building. The study revealed a clear oriented seismic amplification in the fault zone. This effect was observed in intensely jointed rock masses, located inside the fault area, as the result of specific geometries and significant directional impedance contrasts characterizing the area under study. The analyses show that the direction of the largest resonance motions has transversal relationship with the dominant fracture orientation. The directional amplification is inferred to be produced by stiffness anisotropy of the fault damage zone, with larger seismic motions high angle to the fractures. The results obtained are in complete agreement with those obtained by a previous study which analyzed the fault section located to the north-west.Finally, comparing the dynamic properties of the school building and the vibrational characteristics of the soil in the direction of maximum amplification, no clear resonant effect in the soil-structure interaction has been observed.This paper has been funded by the following research projects: “Attività di sviluppo sperimentale finalizzata alla riduzione del rischio sismico nella Sicilia Orientale” inside the PO-FESR 2007-2013 Sicilia; MED-SUV funded from the European Union Seventh Framework Programme (FP7) under Grant agreement n°308665. This work is sponsored by European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement n° 798480

Seismic Hazard Mapping inside the Project SIGMA

The Project SIGMA (Sistema Integrato di sensori in ambiente cloud per la Gestione Multirischio Avanzata) arises from the fields of Information and Communications Technologies (ICT) and advanced applications for the control, monitoring and management of high-risk processes of natural and social origin. SIGMA is a multilevel architecture whose main aim is the acquisition, integration and processing of heterogeneous data from different sources (seismic, volcanic, meteorologic, hydric, pluvial, car traffic, marine traffic, and so on) to manage and elaborate risk mitigation strategies which are important for the emergency management planning. Within the several experimental activities included in the project, there is the designing and realization of a prototype of application platform specialized to provide the operating procedures and software to the public administrations and the industrial companies, for constantly monitoring both the anthropic and natural phenomena in Sicily. In this framework, of course, the seismic risk analysis plays a very important role since Sicily is one of the Italian regions with high seismic risk. Seismic risk assessment may be approached in two different ways: i) as average seismic risk of the buildings and facilities in question during the period considered, combining the vulnerability of different building types and the seismic hazard for the site, which are then expressed in terms of the effects of the events derived from an earthquake catalogue that exceed a specified threshold during a given period; ii) as estimated damage of the buildings and the critical facilities using a scenario input described in terms of the source parameters of the hypocenter as location, magnitude, and so on. Here we deal with the hazard calculation through the code CRISIS (Ordaz, Aguilar and Arboleda) and with the code PROSCEN (PRObabilistic SCENario, [Rotondi and Zonno, 2010]) to obtain earthquake scenario to be used in the latter approach. Indeed, an earthquake scenario is a planning tool that helps decision makers to visualize the specific impact of an earthquake based on the scientific knowledge. An earthquake scenario creates a picture that the members of community can recognize and, at the same time, improves the communication between the scientific, emergency management and policy communities to seismic risk reduction

Real-time urban seismic network and structural monitoring by means of accelerometric sensors: Application to the historic buildings of Catania (Italy)

A real-time urban seismic network for seismic and structural health monitoring is being installed in the city of Catania (Sicily, Italy). The 27 monitoring stations, specifically designed and assembled, equipped with a low-noise 3-axial MEMS accelerometer, are located in 23 high exposure and vulnerability buildings. In this paper we present the characteristics of the monitoring station and of the network. In case of strong seismic events, the system will provide shake maps to the emergency management centre, and will allow to assess the health conditions of the monitored buildings. The network is conceived to be further expandable over the whole historical city centre of the city of Catania.PublishedMilan, Italy1IT. Reti di monitoraggi

Non-Structural Risk Evaluation: Experiences From Pilot Areas Of The Knowrisk Project

This paper presents a multidisciplinary approach to quantify seismic hazard and ground motion intensity parameters for non-structural seismic risk evaluation. In the framework of the European KnowRISK Project, three pilot areas were selected for testing different methodological approaches aimed at evaluating elements and measures to reduce seismic risk coming along with the failure of non-structural elements. At Mt. Etna, Italy, instrumental and historical macroseismic data are used to generate ground motion time series for different scenario events. Risk maps for non-structural damage are generated by using building vulnerability from census data and a damage model based on fragility curves; interstory drift spectra have been also calculated for a representative test site. In South Iceland, scenarios are defined basing on the June 2000 seismic sequence, which provided strong-motion data at several locations. The recorded data and other parameters of the source are used to perform finite-fault simulations of ground motion at different locations in the area and then to calculate interstory drift spectra. In Portugal a scenario referring to the Lower Tagus Valley was selected and finite-fault simulations for the nearby city of Lisbon were performed.PublishedThessaloniki, Greece5T. Sismologia, geofisica e geologia per l'ingegneria sismic

Estimation of Earthquake Early Warning Parameters for Eastern Sicily

Earthquake early warning systems (EEWSs) are becoming a suitable instrument for seismic risk management in real time. In fact, they are implemented or are undergoing testing in many countries around the world because EEWSs represent an effective approach to mitigating seismic risk on a short timescale. EEWSs are based on the use of relationships between some parameters measured on the initial portion of seismic signal after the onsets. Here, we address the first approach to the implementation of EEWS in eastern Sicily, a region that has been hit by several destructive earthquakes. We estimated the peak displacement amplitude of the first portion of P and S waves Pd, the ground-motion period parameter τc, and the peak ground velocity (PGV) from earthquakes with ML ≥2:8 recorded by the broadband stations operated by the Istituto Nazionale di Geofisica e Vulcanologia. We found that the Pd is correlated with the size of the earthquake and may be used to compute the magnitude for an EEWS in this area.We also derived the relationships between τc and ML, and between Pd and PGV, which can be used to provide on-site warning in the area around a given station and to evaluate the potential damaging effects. These relationships may be deemed a useful guide for future implementation of the EEWS in the region.Published1464-14774T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa

Probability hazard map for future vent opening at Etna volcano (Sicily, Italy).

We evaluate a probability hazard map for future vent opening at Etna volcano using a data set of flank vents spanning last 4.0 ka.PublishedVienna, Austria4V. Vulcani e ambienteope

Vents Pattern Analysis at Etna volcano (Sicily, Italy).

We evaluate clustering features at Etna volcano using a dataset of flank vents spanning last 4.0 ka.PublishedVienna, Austria2V. Dinamiche di unrest e scenari pre-eruttiviope