Descrizione 1
Valerio Comerci
The indicator describes the seismic events that occurred in the reference year within the Italian territory, based on the Magnitudes recorded by the National Seismic Network (Rete Sismica Nazionale) of INGV. In 2023, no seismic event was destructive in Italy. Only one event exceeded Magnitude 5, but it had a very deep hypocenter, preventing any surface effects. Furthermore, 19 events with Magnitude between 4 and 4.9 occurred. The strongest earthquake, with a Magnitude of Mw 4.9, occurred near Marradi (FI). The number of earthquakes with Magnitude 2 or higher that occurred in 2023, concentrated mainly along the Apennine Range, the eastern Alps, and eastern Sicily, is comparable to the number of similar events in the previous four years.
This indicator represents significant seismic events in terms of risk. It maps the seismicity across the entire national territory and describes the events with larger Magnitudes. The indicator provides useful information for assessing seismic hazard in Italy.
To describe the seismic hazard of the Italian territory based on the recorded Magnitudes. The information provided by this indicator is essential for raising awareness of seismic risk in Italy, which is crucial for effective territorial planning.
There are no direct regulatory references tied to this indicator. However, there are national and regional regulations related to seismic classification and building codes in seismic zones (see the Seismic Classification and Seismic Microzonation Indicator).
Descrizione 2
- Pignone M., Amato A., 2024. Speciale 2023, un anno di terremoti.
- https://ingvterremoti.com/2024/01/08/speciale-2023-un-anno-di-terremoti/
- https://rischi.protezionecivile.gov.it/it/vulcanico/vulcani-italia/campi-flegrei/il-bradisismo-ai-campi-flegrei/lattuale-crisi/
- SiGeA, 2018. Rischio sismico in Italia: analisi e prospettive per una prevenzione efficace in un Paese fragile. Geologia dell'Ambiente. Supplemento al n. 1/2018. ISSN 1591-5352
- Comerci V., 2006, Il Rischio Sismico in Italia. In: Signorino M. & Mauro F. (a cura di), Disastri Naturali. Conoscere per prevenire. ISAT, con la collaborazione del Dipartimento della Protezione Civile, Roma, pp.19-43.
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Qualificazione dati
INGV site: http://terremoti.ingv.it/
National
2000-2023
Qualificazione indicatore
The information from http://terremoti.ingv.it/ has been mapped using a GIS platform. Additionally, information related to the induced effects of earthquakes, derived from ISPRA surveys or other sources, is provided. For effects on the environment, refer to the Environmental Effects of Earthquakes and Surface Faulting indicators.
In 2023, Italy and the area within 100 km from borders and coastlines experienced 1,936 seismic events with Magnitude 2 or higher. If events that occurred more than 100 km away, in neighboring countries, are included, the total number of earthquakes recorded was 2,015. None of these events in Italy reached Magnitude 6. The strongest earthquake, with Magnitude Mw 5.2, occurred on May 1, 2023, offshore, in front of the north-western Calabrian coast, at a depth of 269 km, which prevented surface effects. Additionally, 19 events of Magnitude between 4 and 4.9 were recorded. The strongest earthquake with an epicenter on land, Magnitude Mw 4.9, occurred 4 km south-west of Marradi (FI), at a depth of around 8 km. This earthquake caused only minor damage to some buildings but no significant damage to properties or people.
As usual, the distribution of seismic events in the national territory was concentrated mainly along the Appennine mountain range, Calabria, northern and eastern Sicily, and, to a lesser extent, the eastern Alps. Despite a decrease compared to previous years, aftershocks from the 2016-2017 seismic sequence in Central Italy still represented around 30% of the seismicity in Italy. Among these, the strongest event was the one in Ussita (MC) on December 16, with ML 3.6. Finally, seismic events at very deep depths continue to occur off the Calabrian coast, due to the ongoing subduction process of the Ionian oceanic crust beneath the Calabrian arc.
In 2023, seismicity in Italy was comparable to that of the last four years in terms of the number of events with Magnitude 2 or higher, and it was lower than that in the years 2009, 2012, and 2016-17, which were characterized by sequences with earthquakes just below or above Magnitude 6. Unlike last year and the previous four years, no event reached Magnitude 5.5. Only one event exceeded Magnitude 5. The number of events between Magnitude 4 and 5.5 in 2023 was nearly the same as the previous year (19 compared to 18) and significantly higher than the previous three years.
Dati
Tabella 1: Terremoti di Magnitudo maggiore o uguale a 4 avvenuti sul territorio italiano nel 2023
Dati INGV, http://terremoti.ingv.it/
ML = Magnitudo Locale; Mw = Magnitudo Momento
Figura 1: Eventi sismici di magnitudo maggiore o uguale a 2 avvenuti nel 2023 in Italia e dintorni
Elaborazione ISPRA da dati INGV (http://terremoti.ingv.it/)
Figura 2: Serie annuale dei terremoti di magnitudo maggiore o uguale a 2 avvenuti in Italia dal 2000 al 2023
Elaborazione ISPRA su dati INGV, http://terremoti.ingv.it/
Figura 3: Serie annuali di terremoti di Magnitudo maggiore o uguale a 4 e a 5,5 avvenuti sul territorio italiano dal 2000 al 2023
Elaborazione ISPRA di dati INGV, http://terremoti.ingv.it/
Fortunately, seismicity in Italy in 2023 did not cause significant damage to properties or people. Of the 2,015 events with Magnitude 2 or higher recorded by the National Seismic Network (INGV), the only event that affected Italy with a Magnitude greater than 5 (Mw 5.2) occurred offshore, in front of the north-western Calabrian coast, at a depth that prevented any surface damage. The strongest earthquake with an epicenter on land was the one in Marradi (FI), with Magnitude Mw 4.9, which caused only minor damage to some buildings. The other 18 earthquakes of Magnitude 4 or higher (Table 1) also caused no significant damage.
In general, the hypocentral depth ranged from 2.6 km to 457.8 km, with most occurring within the first 30 km, where crustal earthquakes take place. The deepest earthquake, occurring in the southern Tyrrhenian Sea, is related to the subduction process of the Ionian oceanic crust beneath the Calabrian arc, which generates earthquakes at great depths. The shallowest earthquakes occurred in the Campi Flegrei area, due to volcano-tectonic dynamics. A new phase of uplift in the Campi Flegrei caldera started in 2005 and continues to this day. As of August 2024, the maximum uplift reached approximately 132.5 cm at Rione Terra in Pozzuoli (the point of maximum deformation of the caldera), with 30.5 cm of this uplift occurring since January 2023. Since 2018, this uplift has been accompanied by an increase in seismic activity, both in the number of earthquakes and their Magnitude.
In 2023, despite most events having Magnitude below 1, there was a noticeable increase in earthquake frequency. Most occurred in the area between Astroni, Solfatara-Pisciarelli-Agnano, Pozzuoli, and the Gulf of Pozzuoli, with maximum depths around 4 km, mainly concentrated within the first 2 km. The strongest events occurred on September 27 and October 2, with Magnitudes 4.2 and 4 respectively. This sequence is continuing into 2024, raising concerns among the population. The Commissione Grandi Rischi has repeatedly stated that the scientific results reinforce the evidence of magma at depth being the trigger for the current bradyseismic crisis. However, in the absence of evidence of magma ascent, the yellow alert level for volcanic risk remains confirmed. It has been deemed necessary to intensify both monitoring activities by the Competence Centers and prevention efforts by various components of the National Service, and to prepare for the possible need to raise the alert level.