Options
Tosi, Patrizia
Loading...
Preferred name
Tosi, Patrizia
Email
patrizia.tosi@ingv.it
Staff
staff
ORCID
Scopus Author ID
7103207181
37 results
Now showing 1 - 10 of 37
- PublicationOpen AccessWeb-based macroseismic survey: fast information exchange and elaboration of seismic intensity effects in Italy(2009-12)
; ; ; ; ;De Rubeis, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Sbarra, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Tosi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Sorrentino, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; ; ; A new method of macroseismic survey, based on voluntary collaboration through the internet, has been running at Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy, since June 2007. The macroseismic questionnaire is addressed to a single nonspecialist person and reported effects are statistically analysed to extrapolate the Mercalli-Cancani-Sieberg (MCS) scale and the European Macroseismic Scale (EMS) intensity referred to by that observer. Maps of macroseismic intensity are displayed online in almost real time and are continuously updated. The aim of the questionnaire is to evaluate seismic effects as felt by the compiler. The final result is a definition of a particular degree of intensity with an evaluation of an associated uncertainty. Results of medium to low magnitude earthquakes are presented here, showing the ability of the method to give fast and interesting results. Effects reported in questionnaires coming from towns are analysed in-depth and assigned intensities are compared with those derived from traditional macroseismic surveys, showing the reliability of the web-based method.999 214 - PublicationOpen AccessLocal seismicity in Rome (Italy): recent results from macroseismic evidences(1996-12)
; ; ; ;Tertulliani, A.; Istituto Nazionale di Geofisica, Roma, Italy ;Tosi, P.; Istituto Nazionale di Geofisica, Roma, Italy ;De Rubeis, V.; Istituto Nazionale di Geofisica, Roma, Italy; ; This paper presents the results obtained from the study of the macroseismic effects of the June 12, 1995 Rome earthquake. The event, MD = 3.8, provoked VI degree MCS effects in neighbourhoods of Southern Rome. This earthquake is important within the framework of seismicity in the Rome area, as it is the first noteworthy one ever to be recorded in the instrumental age, and provides a good comparison with historical earthquakes which have occurred in the same area. The filtering procedure performed on the macroseismic field reveals out the anomalies of the attenuation pattern and the site effect. The results reconfirm what has only recently emerged from the analysis of historical earthquakes, i.e. Rome is affected by local seismicity, that can cause damage in the southern neighbourhoods and the downtown area, especially where the site contributes to the amplification of the effects.149 244 - PublicationOpen AccessSpace-time combined correlation integral and earthquake interactions(2004)
; ; ; ; ;Tosi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;De Rubeis, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Loreto, V.; Centro INFM di Meccanica Statistica e Complessità, Università La Sapienza, Roma, Italy ;Pietronero, L.; Centro INFM di Meccanica Statistica e Complessità, Università La Sapienza, Roma, Italy; ; ; Scale invariant properties of seismicity argue for the presence of complex triggering mechanisms. We propose a new method, based on the space-time combined generalization of the correlation integral, that leads to a self-consistent visualization and analysis of both spatial and temporal correlations. The analysis has been applied on global medium-high seismicity. Results show that earthquakes do interact even on long distances and are correlated in time within defined spatial ranges varying over elapsed time. On that base we redefine the aftershock concept.183 284 - PublicationOpen AccessStacked analysis of earthquake sequences: statistical space-time definition of clustering and Omori law behavior(2010)
; ; ; ;Tosi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;De Rubei, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Sbarra, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; ; ; ; ; ;De Rubeis, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Teisseyre, R.The definition of the aftershocks sequence is still a debated topic. We here propose a study of the spatial and temporal variation of the earthquakes clustering and rate decay. We used five different seismic catalogues, characterized by specific spatial and magnitude ranges. They are respectively: world one, for a global analysis, Greek, Japanese, Californian and Italian regional catalogues in order to investigate different seismo-tectonic settings. A stacking procedure has been applied to characterize a typical sequence behavior and allowing the evaluation of changes over time intervals (107 296 - PublicationOpen AccessQuantification of earthquake diagnostic effects to assess low macroseismic intensities(2020)
; ; ; ; ; ; ; A large amount of data about earthquake effects, supplied by citizens through a web-based questionnaire, enabled the analysis of the occurrence of many of the effects on humans and objects listed in macroseismic scales descriptions. Regarding the other diagnostic effects (rattling, moving, shifting, falling or overturning depending of the object type of doors, windows, china, glasses, small objects, pictures, vases, books, as well as frightened peo- ple and animal behaviour), data from more than 300,000 questionnaires about earthquakes felt in Italy from June 2007 to August 2017, were analysed by stacking them together as a function of hypocentral distance and magnitude. The comparison of the resulting percent- ages with the intensity prediction equation showed that almost all the chosen effects are good diagnostics for macroseismic intensity evaluation, as their percentages are well dif- ferentiated. We did not analyse the oscillations of hanging objects and liquids because the differences in effect attenuations, highlighted by the maps of the occurrence percentage, suggested to not consider them as diagnostic effect. This result allowed us to quantify the occurrence of each diagnostic effect for the intensity degrees from II to VI of the European macroseismic scale for the people who felt the earthquake. The application of the intensity assessment method to internet macroseismic data, based on the specifications herein pro- posed, should mitigate the problem of “not felt” undersampling in crowdsourced web data.199 38 - PublicationOpen AccessMacroseismic effects highlight site response in Rome and its geological signature(2012)
; ; ; ; ; ; ; ; ;Sbarra, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;De Rubeis, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Di Luzio, E.; Istituto per le Tecnologie Applicate ai Beni Culturali (ITABC) ;Mancini, M.; Istituto di Geologia Ambientale e Geoingegneria (IGAG) ;Moscatelli, M.; Istituto di Geologia Ambientale e Geoingegneria (IGAG). ;Stigliano, F.; Istituto di Geologia Ambientale e Geoingegneria (IGAG). ;Tosi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Vallone, R; Istituto di Geologia Ambientale e Geoingegneria (IGAG).; ; ; ; ; ; ; A detailed analysis of the earthquake effects on the urban area of Rome has been conducted for the L’Aquila sequence, which occurred in April 2009, by using an on-line macroseismic questionnaire. Intensity residuals calculated using the mainshock and four aftershocks are analyzed in the light of a very accurate and original geological reconstruction of the subsoil of Rome based on a large amount of wells. The aim of this work is to highlight ground motion amplification areas and to find a correlation with the geological settings at a sub-regional scale, putting in evidence the extreme complexity of the phenomenon and the difficulty of making a simplified model. Correlations between amplification areas and both near-surface and deep geology were found. Moreover, the detailed scale of investigation has permitted us to find a correlation between seismic amplification in recent alluvial settings and subsiding zones, and between heard seismic sound and Tiber alluvial sediments.372 386 - PublicationOpen AccessEarthquake perception data highlight natural frequency details of Italian buildings(2023-04-17)
; ; ; ; ; As the distance from an earthquake increases, the percentage of people who do not feel it also increases. The average transition distance between ‘‘felt’’ and ‘‘not felt’’ reports is mainly determined by the magnitude and depth of the earthquake, but it also depends on the observation floor and building height. Buildings act as resonators and can amplify the shaking at specific frequencies.We analyzed over 286,000 crowdsourced reports to study the effect of floor and building height on earthquake perception. We found that, compared to average values, there is an increase in the percentage of ‘‘felt’’ reports on the highest floors and a decrease in the lowest floors of buildings of all heights.We determined the range within which an observer is likely to feel an earthquake (perception boundary) and examined how it varies with magnitude. We found that as the building height increases, people on higher floors perceive medium to high magnitude earthquakes progressively better than lower magnitude ones. We compared the perception boundary with a model of seismic response spectra to estimate the vibration frequency perceived by observers on each floor/ building height combination. Our results show that the value of the fundamental period increases with building height for the top floor, and that higher vibration modes become more evident for buildings with more than 6 stories. In addition, we observed that the height of the building also affects the vibration of the basement, with the frequency tending to decrease as the building height increases. Concerning macroseismic intensity estimation, we show that in tall buildings, observations made on both the upper and lower floors must be considered outside the normal range, and that earthquake perception also changes as a function of magnitude and distance, pointing out the importance of collecting an adequate number of observations to sample different locations of observers.38 8 - PublicationOpen AccessStatistical study of epicentre alignment in the broader Aegean area(1994-09)
; ; ; ; ;Tosi, P.; Istituto Nazionale di Geofisica, Roma, Italy ;De Rubeis, V.; Istituto Nazionale di Geofisica, Roma, Italy ;Papadirnitriou, E.; Laboratory of Geophysics, Aristotelian University of Thessaloniki, Greece ;Dimitriu, P.; Laboratory of Geophysics, Aristotelian University of Thessaloniki, Greece; ; ; Accurate data concerning shallow (h = 60 km) earthquakes (Ms =4.5) that occurred in the broader Aegean area are used to point out the presence of linear seismogenic structures (seismolineaments). The earthquake data were analyzed by the use of a specific algorithm, and the directions of the best alignment of epicentres were found. The algorithm is based on statistical criteria applied within a circular area with the aim of searching for the best direction of alignment; this is then tested, to discriminate whether or not the pattern could stem from a random distribution of epicentres, or whether it is effectively the result of a linear seismic structure; the procedure is repeated to cover the whole area examined. The resulting lineaments can be regarded as individual tectonic units, as they usually coincide with known active faults or fault systems. An interpretation is given of the spatio-temporal evolution of the seismicity along the lineaments in terms of the asperity model.165 156 - PublicationOpen AccessSeismogenic structure behaviour revealed by spatial clustering of seismicity in the Umbria-Marche Region (Central Italy)(1998-06)
; ;Tosi, P.; Istituto Nazionale di Geofisica, Roma, ItalyTime variations in the spatial distribution of earthquake epicentres are analyzed by application of the fractal correlation dimension method. The zone under investigation is located in Central Italy, bounded in longitude by 12.0 and 14.4 degrees east and in latitude by 42.0 and 43.6 degrees north. From 1st January 1978 to 5th October 1997, 2028 events with a magnitude above Ml= 2.5 constitute the database.Evolution of the spatial fractal dimension Ds permits the identification of seismic cycles that are connected to the occurrence of main earthquakes.In particular, it is possible to recognize a division within each cycle, between a period of random background seismicity and a spatial clustering of events where shocks of magnitude Ml ³occur. Moreover, the decrease in Ds prior to such events, evidences a structural relationship between foreshocks and the occurrence of a main shock, even if not in close territorial proximity.This feature indicates a new, more extensive definition of seismogenic structure which can includes several interconnected structures within a large area.113 210