Dipartimento Della Protezione Civile Research Articles

Relationships between ground motion parameters and macroseismic intensity for Italy

The relation between macroseismic intensity and ground shaking makes it possible to transform instrumental Ground Motion Parameters (GMPs) in macroseismic intensity and vice versa, and is therefore useful for making comparisons between estimates of seismic hazard determined in terms of GMPs and macroseismic intensity, and for other engineering and seismological applications. Empirical relationships between macroseismic intensity and different recorded GMPs for the Italian territory are presented in this paper. The coefficients are calibrated using a dataset of horizontal geometrical mean GMPs, i.e. peak ground acceleration, peak ground velocity, spectral acceleration at 0.2, 0.3, 1.0 and 2.0 s from the ITalian ACcelerometric Archive (ITACA; Luzi et al. in Italian Accelerometric Archive v3.0, Istituto Nazionale di Geofisica e Vulcanologia, Dipartimento della Protezione Civile Nazionale, 2019. https://doi.org/10.13127/itaca.3.0), and macroseismic intensity at Mercalli–Cancani–Sieberg (MCS) scale from the database DBMI15 (Locati et al. in Database Macrosismico Italiano (DBMI15), versione 2.0, Istituto Nazionale di Geofisica e Vulcanologia (INGV), 2019. https://doi.org/10.13127/DBMI/DBMI15.2). A dataset is obtained that corresponds to 240 pairs of macroseismic intensity-GMPs from 67 Italian earthquakes in the time window 1972–2016 with moment magnitude ranging from 4.2 to 6.8 and macroseismic intensity in the range [2, 10–11]. The final dataset correlates strong motion stations and macroseismic intensity observations generally within 2 km from each other, and each association is manually validated through an expert judgement. The adopted functional form is non-linear, predicting macroseismic intensity as a function of LogGMPs and vice versa by performing separate regressions. The set of empirical conversion relationships GMP–IMCS–GMP and the associated standard deviations are compared with previous models. In order to verify the proposed model, a map in terms of PGA is obtained, starting from the PSHA in terms of intensities (Gomez Capera et al. in Bull Seismol Soc Am 100(4):614–1631, 2010. https://doi.org/10.1785/0120090212) and then using the empirical relationship here proposed in PGA, and compared with the National Italian seismic hazard map (Stucchi et al. in Bull Seismol Soc Am 101(4):1885–1911, 2011. https://doi.org/10.1785/0120100130).

Purported precursors: Poor predictors

Author(s): Mulargia, F; Gasperini, P; Lolli, B; Stark, PB | Abstract: The destructive 2009 L'Aquila and 2012 Emilia-Romagna earthquakes led the Italian Dipartimento della Protezione Civile (DPC) to fund nine research groups to investigate seismic precursors. Three research groups produced testable predictions by the DPC deadline of May 31, 2013, based on: 1) radon in a well in Friuli, 2) temperature, flow, CO2 flux, and other variables measured in wells in Emilia-Romagna, and 3) an Artificial Neural Network (ANN) algorithm applied to seismicity. We evaluated the geochemical precursors by comparing their predictions to an equal number of predictions at the same locations and with the same individual and total durations as the actual predictions, but at random times. This approach avoids modelling the seismicity, so the accuracy of the predictions is not influenced by the accuracy of any seismicity model. Neither set of geochemical precursors succeeds significantly better than the random predictions. ANN, on the other hand, did not predict any events large enough to affect public safety.

Le story maps e l'informazione sui terremoti

In recent years, the increasing diffusion of story maps as a new communication and information channel allowed the Istituto Nazionale di Geofisica e Vulcanologia to experience this new technique in the field of seismic risk reduction. Starting from the experiences with the technology of ArcGIS On line for the development of applications on seismicity in Italy, we moved to the realization of some story maps to tell aspects of our territory related to seismic and tsunami risk. In particular, in the context of information campaigns IO NON RISCHIO promoted by the Dipartimento della Protezione Civile, interactive maps have been developed in support of the volunteers involved in information activities in the squares of the campaign. The story maps have been also used as a support for trainings, emergency management, in daily information on earthquakes together with the communication channels that INGV has recently developed for the information platform INGVterremoti (http://ingvterremoti.wordpress.com).

ISMD, a Web Portal for Real-Time Processing and Dissemination of INGV Strong-Motion Data

Online Material: Earthquake catalog and strong motion stations. In Italy, strong‐motion monitoring started in the early 1970s, when the Rete Accelerometrica Nazionale (RAN, the Italian National Strong Motion Network; http://www.protezionecivile.gov.it/jcms/it/ran.wp; see Data and Resources for a complete listing of all websites listed in this article) was designed and installed by the Agenzia Nazionale per le Nuove Tecnologie, l’Energia e lo Sviluppo Economico Sostenibile (ENEA) and ENEL (an Italian power company). The aim was to evaluate the seismic risk in connection with the construction of nuclear power plants. Since 1997, the RAN (Gorini et al. , 2010) has been run by the Dipartimento della Protezione Civile (DPC). At present, the RAN includes about 500 digital strong‐motion stations. The contribution of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) to Italian strong‐motion monitoring started some years later. Through the 2004–2006 agreement between the INGV and the DPC (Strong‐Motion Stations Project), the INGV began the phase of strong‐motion monitoring (Augliera et al. , 2010, 2011). Since 2006, a complete renewal of the (velocimetric) Rete Sismica Nazionale (RSN; Amato and Mele, 2008) was made by installing accelerometers to sites where broadband RSN velocimeters were already present. Altogether, the current ∼150 high‐dynamics digital strong‐motion stations that cover the Italian territory constitute the INGV strong‐motion network. The first channel chosen by the INGV to disseminate the recorded waveforms was through the European Integrated Data Archive (EIDA; http://eida.rm.ingv.it/; http://www.orfeus-eu.org/eida/eida.html), a web portal devoted to seismic data exchange that was developed in the framework of the Network of Research Infrastructures for European Seismology (NERIES) European project (www.neries-eu.org, Networking Activity 3 [NA3]). Since 2008, the INGV raw signals have been downloadable in the Standard for the Exchange of Earthquake Data (SEED) format from the continuous data archive of the INGV National Earthquake Centre (Centro Nazionale Terremoti, CNT). …

CRISIS2008: A Flexible Tool to Perform Probabilistic Seismic Hazard Assessment

In the frame of the Italian research project INGV‐DPC S2 (http://nuovoprogettoesse2.stru.polimi.it/), funded by the Dipartimento della Protezione Civile (DPC; National Civil Protection Department) within the agreement 2007–2009, a tool for probabilistic seismic‐hazard assessment (PSHA) was developed. The main goal of the project was to provide a flexible computational tool for PSHA; the requirements considered essential for the success of the project included: Some commonly used programs (e.g., FRISK by McGuire [1978]; SEISRISK III by Bender and Perkins [1987]) and more recent and state‐of‐the‐art tools (e.g., OpenSHA by Field et al. [2003], http://www.opensha.org;OpenQuake, http://openquake.org) for PSHA were analyzed. We decided to focus on CRISIS2007, which was already a mature and well‐known application (e.g., Kalyan Kumar and Dodagoudar, 2011; Teraphan et al. , 2011; D’Amico et al. , 2012; see also http://ecapra.org/CRISIS-2007), but also suitable for additional development and evolution because its source code is freely available on request. The computational tool resulted in an extensive redesign and renovation of the previous CRISIS2007 version. CRISIS is a computer program for PSHA, originally developed in the late 1980s using FORTRAN as programming language (Ordaz, 1991). In this format, still without a graphical user interface (GUI), it was distributed as part of SEISAN tools (Ottemoller et al. , 2011). Ten years later, a GUI was constructed, generating what was called CRISIS99 (Ordaz, 1999). In this version, all the graphic features were written in Visual Basic, but the computation engine remained a FORTRAN dynamic link library. The reason for the use of mixed‐language programming was that computations …

Seismic Damage Assessment of Unreinforced Masonry Structures After The Abruzzo 2009 Earthquake: The Case Study of the Historical Centers of L'Aquila and Castelvecchio Subequo

The Abruzzo earthquake hit the city of L'Aquila and its surroundings on the April 6, 2009. The aim of this study is to analyze the technical features of unreinforced masonry (URM) buildings and assess their seismic behavior during the Abruzzo 2009 seismic event. The damage induced in the URM constructions of L'Aquila and the suburbs was severe and several such buildings collapsed. This study includes an overview of the dynamic characteristics of the earthquake and the seismic history of the region. The seismic performance of URM buildings is discussed on the basis of both the experience in L'Aquila and the village of Castelvecchio Subequo, during the post-emergency support to the Italian Department of Civil Protection (Dipartimento della Protezione Civile [DPC]), and the field investigation carried out with the patronage of the EU COST Action C26 and the cooperation of the PLINIVS Centre of Naples in three areas of the old city of L'Aquila. The main characteristics of URM buildings, the building behavior and damage are described and reviewed with due respect to the characteristics of the earthquake, as well as with reference to the structural and non-structural characteristics of buildings, using the Italian MEDEA procedure.

ShakeMaps during the Emilia sequence

<p>ShakeMap is a software package that can be used to generate maps of ground shaking for various peak ground motion (PGM) parameters, including peak ground acceleration (PGA), peak ground velocity, and spectral acceleration response at 0.3 s, 1.0 s and 3.0 s, and instrumentally derived intensities. ShakeMap has been implemented in Italy at the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Geophysics and Volcanology) since 2006 (http://shakemap.rm.ingv.it), with the primary aim being to help the Dipartimento della Protezione Civile (DPC; Civil Protection Department) civil defense agency in the definition of rapid and accurate information on where earthquake damage is located, to correctly direct rescue teams and to organize emergency responses. Based on the ShakeMap software package [Wald et al. 1999, Worden et al. 2010], which was developed by the U.S. Geological Survey (USGS), the INGV is constructing shake maps for Ml ≥3.0, with the adoption of a fully automatic procedure based on manually revised locations and magnitudes [Michelini et al. 2008]. The focus of this study is the description of the progressive generation of these shake maps for the sequence that struck the Emilia-Romagna Region in May 2012. […]</p><br />

Recasting Historical Earthquakes in Coastal Areas (Gargano Promontory, Italy): Insights from Marine Paleoseismology

UF was financially supported by MIUR (Italian Ministry of Education and Research) FIRB Project “AIRPLANE”. This research has also benefited from funding provided by the Italian Presidenza del Consiglio dei Ministri – Dipartimento della Protezione Civile (DPC). Scientific papers funded by DPC do not represent its official opinion and policies. This is ISMAR-Bologna contribution n. 1720.

Overview of the Italian strong motion database ITACA 1.0

The Italian Strong Motion Database, ITACA, was developed within projects S6 and S4, funded in the framework of the agreements between the Italian Department of Civil Protection (Dipartimento della Protezione Civile, DPC) and the Istituto Nazionale di Geofisica e Vulcanologia (INGV), starting from 2005. The alpha version of the database was released in 2007 and subsequently upgraded to version 1.0 after: (i) including the most recent strong motion data (from 2005 to 2007) recorded in Italy, in addition to the 2008 Parma earthquake, M 5.4, and the M ≥ 4.0, 2009 Abruzzo seismic events; (ii) processing the raw strong motion data using an updated procedure; (iii) increasing the number of stations with a measured shear wave velocity profile; (iv) improving the utilities to retrieve time series and ground motion parameters; (v) implementing a tool for selecting time series in agreement with design-response spectra; (vi) compiling detailed station reports containing miscellaneous information such as photo, maps and site parameters; (vii) developing procedures for the automatic generation of station reports and for the updating of the header files. After such improvements, ITACA 1.0 was published at the web site http://itaca.mi.ingv.it, in 2010. It presently contains 3,955 three-component waveforms, comprising the most complete catalogue of the Italian accelerometric records in the period 1972–2007 (3,562 records) and the strongest events in the period 2008–2009. Records were mainly acquired by DPC through its Accelerometric National Network (RAN) and, in few cases, by local networks and temporary stations or networks. This paper introduces the published version of the Italian Strong Motion database (ITACA version 1.0) together with main improvements and new functionalities.

OPERATIONAL EARTHQUAKE FORECASTING. State of Knowledge and Guidelines for Utilization

Following the 2009 L'Aquila earthquake, the Dipartimento della Protezione Civile Italiana (DPC), appointed an International Commission on Earthquake Forecasting for Civil Protection (ICEF) to report on the current state of knowledge of short-term prediction and forecasting of tectonic earthquakes and indicate guidelines for utilization of possible forerunners of large earthquakes to drive civil protection actions, including the use of probabilistic seismic hazard analysis in the wake of a large earthquake. The ICEF reviewed research on earthquake prediction and forecasting, drawing from developments in seismically active regions worldwide. A prediction is defined as a deterministic statement that a future earthquake will or will not occur in a particular geographic region, time window, and magnitude range, whereas a forecast gives a probability (greater than zero but less than one) that such an event will occur. Earthquake predictability, the degree to which the future occurrence of earthquakes can be determined from the observable behavior of earthquake systems, is poorly understood. This lack of understanding is reflected in the inability to reliably predict large earthquakes in seismically active regions on short time scales. Most proposed prediction methods rely on the concept of a diagnostic precursor; i.e., some kind of signal observable before earthquakes that indicates with high probability the location, time, and magnitude of an impending event. Precursor methods reviewed here include changes in strain rates, seismic wave speeds, and electrical conductivity; variations of radon concentrations in groundwater, soil, and air; fluctuations in groundwater levels; electromagnetic variations near and above Earth's surface; thermal anomalies; anomalous animal behavior; and seismicity patterns. The search for diagnostic precursors has not yet produced a successful short-term prediction scheme. Therefore, this report focuses on operational earthquake forecasting as the principle means for gathering and disseminating authoritative information about time-dependent seismic hazards to help communities prepare for potentially destructive earthquakes. On short time scales of days and weeks, earthquake sequences show clustering in space and time, as indicated by the aftershocks triggered by large events. Statistical descriptions of clustering explain many features observed in seismicity catalogs, and they can be used to construct forecasts that indicate how earthquake probabilities change over the short term. Properly applied, short-term forecasts have operational utility; for example, in anticipating aftershocks that follow large earthquakes. Although the value of long-term forecasts for ensuring seismic safety is clear, the interpretation of short-term forecasts is problematic, because earthquake probabilities may vary over orders of magnitude but typically remain low in an absolute sense (< 1% per day). Translating such low-probability forecasts into effective decision-making is a difficult challenge. Reports on the current utilization operational forecasting in earthquake risk management were compiled for six countries with high seismic risk: China, Greece, Italy, Japan, Russia, United States. Long-term models are currently the most important forecasting tools for civil protection against earthquake damage, because they guide earthquake safety provisions of building codes, performance-based seismic design, and other risk-reducing engineering practices, such as retrofitting to correct design flaws in older buildings. Short-term forecasting of aftershocks is practiced by several countries among those surveyed, but operational earthquake forecasting has not been fully implemented (i.e., regularly updated and on a national scale) in any of them. Based on the experience accumulated in seismically active regions, the ICEF has provided to DPC a set of recommendations on the utilization of operational forecasting in Italy, which may also be useful in other countries. The public should be provided with open sources of information about the short-term probabilities of future earthquakes that are authoritative, scientific, consistent, and timely. Advisories should be based on operationally qualified, regularly updated seismicity forecasting systems that have been rigorously reviewed and updated by experts in the creation, delivery, and utility of earthquake information. The quality of all operational models should be evaluated for reliability and skill by retrospective testing, and they should be under continuous prospective testing against established long-term forecasts and alternative time-dependent models. Alert procedures should be standardized to facilitate decisions at different levels of government and among the public. Earthquake probability thresholds should be established to guide alert levels based on objective analysis of costs and benefits, as well as the less tangible aspects of value-of-information, such as gains in psychological preparedness and resilience. The principles of effective public communication established by social science research should be applied to the delivery of seismic hazard information.

Development of a site-conditions map for the Campania-Lucania region (southern Apennines, Italy)

Having a reliable site-conditions estimate is an important step to analyze and predict earthquake ground motions. To provide this information for the Campania-Lucania region (southern Apennines, Italy), and in the framework of a collaboration with the regional branch of the Dipartimento della Protezione Civile (Italian National Civil Protection Agency), the geological units shown on a 1:250,000 scale geological map have been combined together into four categories based on age and geological similarities. According to the site classification defined in engineering building codes, each site has been assigned a class, a value or range of values of the average shear-wave velocity to 30 m (Vs30), and the site-dominant period. Thus, we have digitized the category boundaries from the map, tracing only the geological contacts that separate the units of different site classes. The accuracy of the site-conditions map is only limited by the number of Vs profiles used to compute the Vs30, and geologic data available to date. Analyses with new data will allow updates and modifications to this map. The resulting site classification map provides a helpful tool to better characterize the site effects for those applications where amplification values at large scale are need, such as ground-shaking maps or seismic hazard maps.

The ITalian ACcelerometric Archive (ITACA): processing of strong-motion data

The Italian strong-motion database was created during a joint project between Istituto Nazionale di Geofisica e Vulcanologia (INGV, Italian Institute for Geophysics and Vulcanology) and Dipartimento della Protezione Civile (DPC, Italian Civil Protection). The aim of the project was the collection, homogenization and distribution of strong motion data acquired in Italy in the period 1972–2004 by different institutions, namely Ente Nazionale per l’Energia Elettrica (ENEL, Italian electricity company), Ente per le Nuove tecnologie, l’Energia e l’Ambiente (ENEA, Italian energy and environment organization) and DPC. Recently the strong-motion data relative to the 23th December 2009, Parma (Mw = 5.4 and Mw = 4.9) and to the April 2009 L’Aquila sequences (13 earthquakes with 4.1 ≤ Mw ≤ 6.3) were included in the Italian Accelerometric Archive (ITACA) database (beta release). The database contains 7,038 waveforms from analog and digital instruments, generated by 1.019 earthquakes with magnitude up to 6.9 and can be accessed on-line at the web site http://itaca.mi.ingv.it. The strong motion data are provided in the unprocessed and processed versions. This article describes the steps followed to process the acceleration time series recorded by analogue and digital instruments. The procedures implemented involve: baseline removal, instrumental correction, band pass filtering with acausal filters, integration of the corrected acceleration in order to obtain velocity and displacement waveforms, computation of acceleration response spectra and strong motion parameters. This procedure is applied to each accelerogram and it is realised to preserve the low frequency content of the records.

Volcanic hazard at Vesuvius: An analysis for the revision of the current emergency plan

Mt Somma-Vesuvius is a composite volcano on the southern margin of the Campanian Plain which has been active since 39 ka BP and which poses a hazard and risk for the people living around its base. The volcano last erupted in 1944, and since this date has been in repose. As the level of volcanic risk perception is very high in the scientific community, in 1995 a hazard and risk evaluation, and evacuation plan, was published by the Italian Department of Civil Protection ( Dipartimento della Protezione Civile) . The plan considered the response to a worst-case scenario, taken to be a subplinian eruption on the scale of the 1631 AD eruption, and based on a volcanological reconstruction of this eruption, assumes that a future eruption will be preceded by about two weeks of ground uplift at the volcano's summit, and about one week of locally perceptible seismic activity. Moreover, by analogy with the 1631 events, the plan assumes that ash fall and pyroclastic flow should be recognized as the primary volcanic hazard. To design the response to this subplinian eruption, the emergency plan divided the Somma-Vesuvius region into three hazard zones affected by pyroclastic flows (Red Zone), tephra fall (Yellow and Green Zone), and floods (Blue Zone). The plan at present is the subject of much controversy, and, in our opinion, several assumptions need to be modified according to the following arguments: a) For the precursory unrest problem, recent scientific studies show that at present neither forecast capability is realistic, so that the assumption that a future eruption will be preceded by about two weeks of forecasts need to be modified; b) Regarding the exposure of the Vesuvius region to flow phenomena, the Red Zone presents much inconsistency near the outer border as it has been defined by the administrative limits of the eighteen municipality area lying on the volcano. As this outer limit shows no uniformity, a pressing need exists to define appropriately the flow hazard zone, since there are some important public structures not considered in the current Red Zone that could be exposed to flow risk; c) Modern wind records clearly indicate that at the time of a future eruption winds could blow not only from the west, but also from the east, so that the Yellow Zone (the area with the potential to be affected by significant tephra fall deposits) must be redefined. As a result the relationship between the Yellow Zone and Green Zone (the area within and beyond which the impact of tephra fall is expected to be insignificant) must be reconsidered mainly in the Naples area; d) The May 1998 landslide, caused in the Apennine region east of the volcano by continuous rain fall, led to the definition of a zone affected by re-mobilisation of tephra (Blue Zone), confined in the Nola valley. However, as described in the 1631 chronicles of the eruption, if generation of debris flows occurs during and after a future eruption, a much wider region east of the Somma-Vesuvius must be affected by events of this type.

The Italian strong motion network

The Italian Strong Motion Network is a permanent monitoring system run by the Italian national emergency management department (Dipartimento della Protezione Civile, DPC). The network is known as RAN (Rete Accelerometrica Nazionale). An extensive project for updating and improving the technology of RAN instruments as well as the number of recording points was performed in the last 10 years. A wide site selection survey was carried out from eastern Sicily along the Italian peninsula, covering high seismic risk areas. The recording station density and the choice of high-quality digital strong motion instruments ensure reliability of the RAN network in the long-term. At the end of 2008, the free field sites selection and instruments installation, planned in the project, were quite completed. In planning and drawing the new RAN, special attention has been devoted to the robustness of the transmission systems, and to the distribution of new stations in order to ensure plenty of data during a seismic emergency. We spent special care both in the estimation of the RAN site responses and in the diffusion of the strong motion data. In order to better identify damaged earthquake areas, improved ground motion parameters need to be set. Such parameters will also assist future progress for engineering seismic design techniques as well as disaster mitigation.

ITACA (ITalian ACcelerometric Archive): A Web Portal for the Dissemination of Italian Strong-motion Data

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A WebGIS Application for Rendering Seismic Hazard Data in Italy

In 2004, on behalf of the Department of Civil Protection (DPC—Dipartimento della Protezione Civile), the Istituto Nazionale di Geofisica e Vulcanologia (INGV) released a new Italian seismic hazard map. The entire scientific process was public and transparent: an international panel of experts conducted a peer review while the work was in progress, and all the input data, the final output, and the technical documentation was published. The details of the entire process are available on a dedicated Web site (http://zonesismiche.mi.ingv.it). The new hazard map provides the expected value of horizontal peak ground acceleration (PGA) with an exceedance probability of 10% in 50 years. This elaboration was recently adopted (ordinance 3519/2006 signed by the Prime Minister) as the “reference map” for assigning municipalities to one of four seismic zones according to building-code criteria. In the building code released in 2005 (ministerial decree 14/09/2005), the seismic zone assignment criteria is the expected PGA value; for each seismic zone the code also defines a standard design spectrum anchored to a fixed PGA value allowing designers to change the anchor value of the response spectra within a 20% discretionary margin when more detailed information on the expected shaking parameters of the site of interest are available. In addition to the scientific community, local administrators and professionals, typically civil engineers and architects, use seismic hazard values. Administrators use them to define the appropriate level of protection for the regions they oversee, while professionals refer to them to provide the best compromise between building costs and safety. Following the publication of the reference map, the DPC financed the S1 project to produce a set of additional elaborations that would better describe the Italian seismic hazard. This resulted in a set of maps expressed in terms of PGA and Sa (spectral accelerations), both evaluated for different …