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The article provides a comprehensive earthquake catalogue for the eastern Alps from 1977 to 2022, focusing on seismic activity in NE Italy. The National Institute of Oceanography and Applied Geophysics manages the Monitoring System for NE Italy, which monitors and researches earthquakes in the region. The catalogue includes earthquake locations and magnitudes, and the article explains the data sources and methods used. It also discusses the reliability of earthquake solutions and the selection process for creating the final catalog. The document is a list of references and citations for scientific papers and reports on earthquake monitoring, location determination, magnitude calculation, and historical analysis in northeastern Italy. These sources are valuable for researchers studying earthquakes in the region. [Extracted from the article]

Regular monitoring of the seismicity in north-eastern Italy began in 1977, one year after the strong earthquake that caused about 1000 victims in Friuli. Over the years, the monitoring network operated by OGS has increased, today reaching a consolidated level in terms of geometry and number of stations. Furthermore, the entire data acquisition and processing system, which has changed over the years, is currently also highly robust. After the huge number of studies on the 1976 seismic sequence and on the regional seismicity developed in the 1970s and 1980s, the present paper illustrates a comprehensive work on the subject since the beginning of the 21st century. With this work, we take up the thread and analyse the evolution of seismicity in the first two decades of the 21st century (2000-2021). As part of the study, we took a retrospective look at the qualitative development of the data provided by OGS over time, basically focusing on the earthquake catalogue obtained by the network recordings and developing a new relation for calculating the duration magnitude. [ABSTRACT FROM AUTHOR]

The duration magnitudes in the North-Eastern Italy Seismic Network (OX) catalogue have been thoroughly revised. Historically, but also today for homogeneous continuity with the past, this catalogue, released yearly by the National Institute for Oceanography and Experimental Geophysics, provides local magnitudes in terms of duration magnitude (MD). Unfortunately, the earthquake total durations were calibrated on a local Richter magnitude (ML) data set characterized by a demonstrated small bias. In this work, based on a revised and corrected ML catalogue of the Trieste seismological station, computed in accordance with the original Wood Anderson requirements and validated in turn with the available moment magnitude estimates, new linear empirical regressions between ML and earthquake total duration have been performed, aimed at producing a homogeneous catalogue of locations and MD for the eastern Southern Alps. [ABSTRACT FROM AUTHOR]

Although earthquake prediction remains an ultimate goal of seismology, up to now only a very few events have actually been forecasted, while for many of them wrong or doubtful predictions were given and even some misunderstandings were produced. After reporting a couple of examples on the subject, the paper focuses on an accurate revision of the seismological data of the 1976 seismic sequence in Friuli (northeastern Italy), as well as on the analysis of the space distribution of the earthquakes aiming at investigating if any clue of possible identification of the epicentre of the main aftershocks was possible at that time or should be possible today. The final consideration is that, even with a good (or good enough) seismic monitoring, there was no clear evidence of epicentre migration towards the future location of the major events. [ABSTRACT FROM AUTHOR]

Three hundred and seventy-five earthquakes recorded by the Trieste station in the eastern Alps in the early instrumental period, i.e., before the occurrence of the destructive event of May 6, 1976, have been located after painstaking gathering of seismograms and bulletins. Analysis of the statistical parameters of the locations, together with comparisons with other instrumental and macroseismic locations, have allowed us to assess the quality of the results obtained, taking into account the often limited nature of the data. Using a process of digitization and the study of seismograms, focal parameters, particularly the magnitude MW, have been recovered for three earthquakes of the 1950s and 1960s. [ABSTRACT FROM AUTHOR]

The SEAHELLARC project, supported by the European Commission, aimed at evaluating and computing seismic hazard and risk, as well as modelling tsunamis for the town of Pylos, in the western Peloponnese and neighboring region. This paper describes the main scopes and results of the project. [ABSTRACT FROM AUTHOR]

The accurate prediction of the ground motion is of utmost importance in the seismic hazard assessment. 3D or 2D modelling is desirable to obtain realistic estimates of ground motion, but often the shortage of information about source and crustal structures compels us to adopt simplified techniques. In this paper we propose and test an expeditious methodology to compute near field ground motion including source and 1D site effects. Our methodology is based on a stochastic finite-fault modelling technique together with a 1D code to generate the soil response. As study area we choose the Friuli region in north-eastern Italy, seen as optimal since it was possible to identify a zone, located in the Friuli plain, and some sites at short distance with different soil conditions where past earthquakes produced severe damage. The 1936 Cansiglio earthquake (MS=5.8) and the May 6, 1976 (MS=6.5) Friuli earthquake, together with three aftershocks of the 1976 seismic sequence with ML ranging between 4.3 and 5.8, were chosen as target events to validate our procedure in a wide frequency contents. We compare peak ground motions or response spectra derived from the synthetic signals with those obtained from the recordings at bedrock or soil stations. When none (1936 Cansiglio earthquake) or few recordings are available (1976 Friuli earthquake), we compare the intensities derived from response spectra with the macroseismic observations. As a final step, we compute the expected ground motion generated by two scenario earthquakes of M=6.7, that is the maximum magnitude expected for the area under investigation. [ABSTRACT FROM AUTHOR]

Anomalous geochemical signals inferred from elemental and isotopic analyses on spring waters and soil degassing are often detected in response to tectonic loading along faults. Recent results highlighted how the geochemical anomalies are closely related to episodes of crustal deformation. In the present study, the carbon dioxide and radon from soil degassing and the geochemical features of springs spatially related to fault zones in the Friuli-Venezia Giulia region (north-eastern Italy), a seismic-prone area, have been coupled with crustal deformation analyses to better define the possible correlations between fluctuations of geochemical parameters and seismicity, with the aim of gaining new information about local geodynamic processes. The natural CO2 and Rn degassing was evaluated by a soil gas survey carried out by a grid of about 100 measuring sites located over the area that had been hit by strong earthquakes, in the past (Gemona - Idrija 1511, Raveo 1700, Tolmezzo 1788 and 1928, Gemona 1976). The results obtained show a significant amount of crustal-originated gases, especially CO2, possibly related to decarbonation reactions and stress accumulation occurring in deep-seated structures. The spring waters show, in some cases, anomalous geochemical transients, in particular concerning the chloride and Rn concentration, that are not related to seasonal changes and interpreted to reflect distinct fluid pressure regimes within the fault zone, yielding the leakage of pore fluids into the country-rock aquifers. In particular, the changes in the chloride content have been tentatively modeled in terms of pore-fluid expulsion from compacting clays during pressure gradients at shallow crustal levels. The flow regimes and chemical evolution have been related to the strain computed at the outlet sites through the Gutenberg-Richter relation parameters and the regional value of the strain rate. The information provided here may be used to start up a long-term geochemical monitoring of this seismically active area able to detect the modifications occurring in the circulating fluids to gain a better insight on the relationships between the geochemistry of the fluids and the activity of the local seismogenic faults. [ABSTRACT FROM AUTHOR]