doi: 10.13127/BSI/202303
D. Cheloni, A. Sciarra, M. De Caro, M. Pastori, L. Improta, L. Scognamiglio, C. Castellano, A. Frepoli, M. Quintiliani, P. Battelli, M. Berardi, C. Melorio, G. Modica, A. Nardi, N.M. Pagliuca, A. Malagnini, A. Marchetti, L. Miconi, A.M. Lombardi, A. Rossi, L. Arcoraci, A. Battelli, B. Cantucci, L. Colini, A. Lisi, G. Mele, V. Misiti, S. Spadoni, R. Tardini, C. Thermes, M.T. Mariucci, B. Castello, C. Montuori, T. Sgroi
Collaborators: V. Lauciani, D. Latorre, A. Mandiello, S. Pintore, L. Margheriti, P. Baccheschi M.G. Ciaccio.
The review by BSI analysts of the seismic activity recorded in Italy from January 1 to April 30, 2023, included all earthquakes with magnitude M≥1.5, while the parameters of earthquakes with a lower magnitude were those calculated in real-time in the seismic monitoring room in Rome. The strongest earthquakes (M≥3.5) and a few others of particular interest [see Marchetti et al., 2016, DOI: 10.4401/ag-6116] were reviewed by BSI analysts, on average, within 24 hours after their occurrence.
In the third four-month period of 2023, six seismic events with M≥4.0 were recorded. The first occurred on September 13 (Mw=4.0) off the coast of the Marche-Ancona region, while the mainshock of Mw=4.9 of the sequence occurred on the 18th of the same month in the municipality of Marradi (FI). On October 25 and 28, two events, both of ML=4.2, were located near the municipality of Ceneselli, in the province of Rovigo. The last two earthquakes of the four-month period are instead linked to the subduction process of the Tyrrhenian slab: the first is on October 26, ML=4.3, which occurred off the Sorrento peninsula, while the second is on November 20 with ML=4.6, which occurred in the Southern Tyrrhenian Sea. Both had a hypocentral depth well over 400 km.
doi: 10.13127/BSI/202302
A. Mandiello, R. Tardini, A. Sciarra, S. Spadoni, A. Frepoli, G. Modica, S. Pinzi, M. Quintiliani, V. Lauciani, P. Battelli, M. Berardi, C. Melorio, A. Nardi, C. Castellano, N.M. Pagliuca, A. Malagnini, A. Marchetti, L. Miconi, A. Rossi, L. Arcoraci, A. Battelli, B. Cantucci, D. Cheloni, L. Colini, A. Lisi, G. Mele G, V. Misiti, C. Thermes, M. De Caro, M.T. Mariucci, B. Castello, C. Montuori, M. Pastori, T. Sgroi
Collaborators: D. Latorre, A. Bono, L. Improta, L. Margheriti, L. Scognamiglio, P. Baccheschi, M.G. Ciaccio.
The review by BSI analysts of the seismic activity recorded in Italy from January 1 to April 30, 2023, included all earthquakes with magnitude M≥1.5, while the parameters of earthquakes with a lower magnitude were those calculated in real-time in the seismic monitoring room in Rome. The strongest earthquakes (M≥3.5) and a few others of particular interest [see Marchetti et al., 2016, DOI: 10.4401/ag-6116] were reviewed by BSI analysts, on average, within 24 hours after their occurrence.
In the second four-month period of 2023, three seismic events with a magnitude greater than or equal to 4.0 occurred. The strongest of these had a magnitude Mw=5.2 and occurred on May 1st off the north-western Calabrian coast at a hypocentral depth of almost 300 km. On June 21st, however, an earthquake of Mw=4.1 was located at sea along the northern coast of the Gargano Promontory. Finally, on July 5th, a seismic event of Mw=4.0 occurred in Cesarò, in the province of Messina.
BSI Working Group (2015) Bollettino Sismico Italiano (BSI). Istituto Nazionale di Geofisica e
Vulcanologia
https://doi.org/10.13127/bsi
The Bollettino Sismico Italiano (BSI) (Italian Seismic Bulletin), produced by ING (now INGV), was established in the 1980s, and thus celebrated its 40th anniversary in 2025. The BSI is the catalogue of hypocentral location parameters and magnitudes of seismic events that occurred in Italy and in border areas, recorded by the stations of the National Seismic Network (RSN) and other regional and foreign networks managed by other institutions, and has been available in digital format since 1985.
The activity of its Working Group (GdL BSI) has had and has as its objective the publication of the most accurate catalogue possible, leading to a significant increase in located earthquakes and greater precision in data analysis.
For the period 1985-2024, the BSI contains more than 450,000 earthquakes located on the Italian territory and in adjacent areas: of these, about 106,000 have a magnitude equal to or greater than 2.0.
The GdL BSI, especially in the last 10 years, has carried out other relevant activities including:
For further details, you can consult the post on the ingvterremoti blog.
Joint SGI-SIMP congress, Bari, September 3-5 2024
Mele G., Battelli P., Castello B., Carluccio I., Ciaccio M.G., Della Bina E., Lauciani V., Di Stefano R., Nardi A., Maniscalco M., Marchetti A., Latorre D. & BSI Working Group
From September 3 to 5, 2024, the joint Congress of SGI (Italian Geological Society) and SIMP (Italian Society of Mineralogy and Petrology), titled "Geology for a Sustainable Management of Our Planet", was held at the University Campus of Bari. During session S36, Challenges in the Characterization of Active Faults: The Contribution from Seismology, Geodesy, and Structural Analysis, Giuliana Mele, of the Roma1 section of the INGV in Rome, presented the contribution "The new website of the Italian Seismic Bulletin (BSI): architecture and content". In the presentation, the content of the new BSI website http://bsi.ingv.it was illustrated, highlighting the differences between real-time monitoring, carried out by shift workers in the Seismic Surveillance and Tsunami Warning Room in Rome, and research purposes, conducted, among others, by the BSI Working Group. The crucial role of the relocalization of seismic events by BSI analysts was also underlined, which allows to refine the estimates of the hypocentral parameters, contributing to the identification of the structures activated by earthquakes and to the definition of their geometry. The applications of this activity include, in addition to the analysis of Italian seismicity, the modeling of seismogenic structures and any studies on seismic risk.
Mele G., Battelli P., Castello B., Carluccio I., Ciaccio M.G., Della Bina E., Lauciani V., Di
Stefano R., Nardi A., Maniscalco M., Marchetti A., Latorre D. & BSI Working Group*
* BSI Working Group: Arcoraci L., Bagh S., Battelli A., Berardi M., Cantucci B., Castellano C.,
Cheloni D., Cirella A., Colini L., De Caro M., Frepoli A., Improta L., Lisi A., Lombardi A.M.,
Malagnini A., Margheriti L., Mariucci M.T., Melorio C., Michele M., Miconi L., Misiti V., Modica
G., Monna S., Montuori C., Pagliuca N., Pastori M., Pinzi S., Pizzino L., Rossi A., Sciarra A.,
Sgroi T., Smedile A., Spadoni S., Tardini R., Thermes C., Bono A., Fares M., Franceschi D.,
Mandiello A., Moretti M., Pintore S., Quintiliani M., Scognamiglio L. (2024). The new website of
the Italian Seismic Bulletin (BSI): architecture and content. Congresso congiunto SGI-SIMP
“Geology for a sustainable management of our Planet” - Bari, 3-5 settembre 2024 (presentazione
orale). doi.org/10.3301/ABSGI.2024.02
doi: 10.13127/BSI/202301
A. Lisi, M.T. Mariucci, G. Mele, B. Castello, C. Montuori, L. Scognamiglio, A. Marchetti, A. Mandiello, A. Bono, V. Lauciani, P. Battelli, M. Berardi, C. Melorio, G. Modica, A. Nardi, C. Castellano, N.M. Pagliuca, A. Malagnini, L. Miconi, S. Pinzi, A.M. Lombardi, A. Rossi, L. Arcoraci, A. Battelli, B. Cantucci, D. Cheloni, L. Colini, V. Misiti, L. Pizzino, A. Sciarra, S. Spadoni, R. Tardini, C. Thermes, M. De Caro, A. Frepoli, M. Pastori, T. Sgroi, D. Latorre, S. Pintore, M. Quintiliani
Collaborators: L. Improta, L. Margheriti, L. Scognamiglio, P. Baccheschi.
The review by BSI analysts of the seismic activity recorded in Italy from January 1 to April 30, 2023, included all earthquakes with magnitude M≥1.5, while the parameters of earthquakes with a lower magnitude were those calculated in real-time in the seismic monitoring room in Rome. The strongest earthquakes (M≥3.5) and a few others of particular interest [see Marchetti et al., 2016, DOI: 10.4401/ag-6116] were reviewed by BSI analysts, on average, within 24 hours after their occurrence.
In the first four-months period of 2023, the most significant seismic events occurred on January 28 in Cesenatico (FC) with Mw=4.1, on March 9 in Umbertide (PG) with Mw=4.5, and on March 30 in Montagano (CB) with Mw=4.6. Additionally, there was an earthquake on February 27, in the southern Tyrrhenian Sea, at a depth of over 400 km (ML=4.3), and the strongest event of the sequence recorded south of Malta, occurred on April 21 (ML=5.5).
doi: 10.13127/BSI/202203
M. Quintiliani, A. Battelli, D. Cheloni, A. Sciarra, L. Pizzino, V. Misiti, A. Malagnini, S. Spadoni, R. Tardini, G. Mele, P. Battelli, M. Berardi, C. Melorio, G. Modica, A. Nardi, C. Castellano, N.M. Pagliuca, A. Marchetti, L. Miconi, S. Pinzi, M. Pirro, A. Rossi, L. Arcoraci, B. Cantucci, A. Lisi, C. Thermes, M.T. Mariucci, L. Colini, C. Montuori, M. Pastori, M. De Caro, S. Monna, T. Sgroi, A. Smedile, A. Frepoli, B. Castello, V. Lauciani, D. Latorre, A. Bono, A.G. Mandiello, S. Pintore, M.G. Ciaccio
Collaborators: L. Improta, L. Margheriti, L. Scognamiglio, P. Baccheschi.
The review by BSI analysts of the seismic activity recorded in Italy from September 1 to December 31, 2022, included all earthquakes with magnitude M≥1.5, while the parameters of earthquakes with a lower magnitude were those calculated in real-time in the seismic monitoring room in Rome. The strongest earthquakes (M≥3.5) and a few others of particular interest [see Marchetti et al., 2016, DOI: 10.4401/ag-6116] were reviewed by BSI analysts, on average, within 24 hours after their occurrence.
In the third four-month period of 2022, three seismic events with a magnitude greater than 5 were recorded: the first on October 31 in the Gulf of Policastro (SA and PZ provinces) with Mw=5.4 and a depth of about 280 km, the second and third occurred offshore along the Marche-Pesaro coast on November 9 with Mw=5.5 and ML=5.2 respectively, initiating a significant seismic sequence with 15 aftershocks of ML≥3.5 during the four-month period.
Margheriti L., Latorre D., Castello B., Ciaccio M.G., Di Stefano R., Lisi L., Marchetti A., Michele M., Nardi A., Scognamiglio L., and BSI working group
From June 23 to 25, 2024, the II edition workshop of the CRUST project
(Interuniversity Center for 3D Seismotectonics with territorial applications;
https://www.crust.unich.it) titled “Tools, data, and
models for 3D seismotectonics: the Italian
over time laboratory” took place. In the session “Observational seismology for seismotectonics,”
the contribution “Updated earthquake catalogs of the
Italian Seismicity” by the Working Group of
the Italian Seismic Bulletin (BSI) was presented.
In the presentation, Lucia Margheriti (Director of the National Earthquake Observatory)
illustrated the earthquake catalogs of Italian seismicity obtained by applying a probabilistic
localization method using BSI data and both 1D regional and
3D tomographic models of Italy. The presentation discussed the differences between the various
catalogs and described some examples of earthquake distribution in the Italian region,
particularly regarding the Amatrice-Visso-Norcia sequences of 2016-17 and the Marradi (FI)
sequence of September 2023. The probabilistic localization catalogs of the BSI will be
distributed through the new web page of the Working Group (http://bsi.ingv.it) along with the
standard localization catalogs of the BSI.
Margheriti L., Latorre D. Castello B., Ciaccio M.G., Di Stefano R.,
Lisi L., Marchetti A., Michele M., Nardi A., Scognamiglio L., and BSI working group*
*L. Arcoraci, S. Bagh, A. Battelli, P. Battelli, M. Berardi, B. Cantucci, I. Carluccio, B.
Castello, C. Castellano, D. Cheloni, M.G. Ciaccio, A. Cirella, L. Colini, M. De Caro, E. Della
Bina, R. Di Stefano, A. Frepoli, L. Improta, D. Latorre, A. Lisi, A.M. Lombardi, V. Lauciani, A.
Malagnini, M. Maniscalco, A. Marchetti, L. Margheriti, M.T. Mariucci, G. Mele, C. Melorio, M.
Michele, L. Miconi, V. Misiti, G. Modica, C. Montuori, A. Nardi, N. Pagliuca, M. Pastori, S.
Pinzi, L. Pizzino, A. Rossi, A. Sciarra, T. Sgroi, S. Spadoni, R. Tardini, C. Thermes, A. Bono,
M. Fares, D. Franceschi, A. Mandiello, M. Moretti, S. Pintore, M. Quintiliani, L. Scognamiglio
(2024). Updated earthquake catalogs of the Italian Seismicity. Crust Workshop, II edition,
Campus University D’Annunzio, Chieti, 23-25 giugno 2024 (presentazione orale).
Lisi A., Arcoraci L., Battelli P., Berardi M., Castello B., Latorre D., Marchetti A., Michele M., Misiti V., Nardi A., Piccinini D., Rossi A., and Gruppo di Lavoro del BSI
On September 18, 2023, an earthquake with a magnitude of ML=4.8 (Mw=4.9) occurred a few kilometers southwest of Marradi (FI), at a depth of about 8 kilometers. The focal solution calculated using the TDMT suggests a normal fault oriented NW-SE (Scognamiglio et al., 2006). The earthquake, preceded by a foreshock of magnitude ML=3.3 (Mw=3.4), triggered a seismic sequence characterized, in the first two months, by about 700 events located by the on-duty staff at the INGV Seismic Monitoring Room in Rome. Of these 700 earthquakes, 6 events with magnitudes ML ≥ 3.0 occurred within the first two days.
The BSI group analyzed the first three days of the sequence, paying particular attention to the hours immediately following the main shock. Through this analysis, they identified an earthquake with a magnitude of ML=3.4 that occurred about one minute after the main shock and was not processed by the on-duty staff in the monitoring room. The events reviewed by the BSI analysts (approximately 30% more than those located in the monitoring room during the first three days) were also re-located using the NonLinLoc code (Lomax et al., 2000) with the 1-D regional velocity model of Pastori et al. (2019). Additionally, relative relocations were made using double-difference methods (Waldhauser and Schaff, 2008) to try to define the geometries of the activated structures (see Figure). Simultaneously, for the period from September 1 to October 10, an analysis using the template matching technique was applied to identify events that were not processed by the Earthworm automatic location system used in the Rome monitoring room. It was found that the number of detections increased by about 60%. This result highlights the value of the analysis performed by the BSI working group.
Lisi A., Arcoraci L., Battelli P., Berardi M., Castello B., Latorre D., Marchetti A., Michele M., Misiti V., Nardi A., Piccinini D., Rossi A., and Gruppo di Lavoro del BSI (2024). Analysis and preliminary results of the Mw 4.9, Marradi seismic sequence (September 18th, 2023), in the northern Apennines, carried out by the BSI working group. 42° GNGTS Conference, Ferrara, 13-16 February 2024 (abstract and oral presentation), http://hdl.handle.net/2122/17070
During the third ONT Day
held at the INGV headquarters in Rome on November 14, 2023, the BSI Working Group presented two
contributions: the first on the progress of the new BSI website (oral presentation) and the
second on the analysis of the seismic sequence in Marradi, province of Florence, on September
18, 2023 (poster).
Both contributions were subsequently published as individual works in the
Miscellanea no. 79 of the INGV Editorial Series, realized to document this technical-scientific
day on the various topics discussed at ONT as well as the latest research results, technological
developments, and services offered to the community.
Stramondo S., Moretti M., Bignami C., Nardi A., Pastori M., Franceschi D., Esposito A., Mandiello G.A., Scognamiglio L., Valoroso L., Polcari M., Nostro C., Piatanesi A., Pignone M., Rao S. (Eds.), (2024). Giornata ONT 2023 Proceedings Volume, Rome 14th November 2023, Misc. INGV, 79: 1206. https://doi.org/10.13127/misc/79
Below are the link and DOI for the two contributions presented by the GdL BSI at ONT Day
2023:
Italian Seismic Bulletin working group: new web site and data dissemination
strategies
Barbara Castello, Patrizia Battelli, Michele Maniscalco, Ivano Carluccio, Emiliano Della Bina,
Valentino Lauciani, Raffaele Di Stefano, Anna Nardi, Alessandro Marchetti, Diana Latorre, Maria
Grazia Ciaccio and BSI working group
https://doi.org/10.13127/misc/79/12
The September 18th, 2023, MW 4.9, earthquake in the northern Apennines (Marradi, FI):
the work of the BSI on the early days of the seismic sequence
Arianna Lisi, Luca Arcoraci, Patrizia Battelli, Michele Berardi, Barbara Castello,
Maria Grazia Ciaccio, Diana Latorre, Alessandro Marchetti, Maddalena Michele, Valeria Misiti,
Anna Nardi, Davide Piccinini, Antonio Rossi and BSI working group
https://doi.org/10.13127/misc/79/25
doi: 10.13127/BSI/202202
M.G. Ciaccio, A. Mandiello, L. Colini, A. Battelli, G. Mele, V. Misiti, A. Malagnini, A. Frepoli, R. Tardini, D. Cheloni, P. Battelli, M. Berardi, C. Melorio, G. Modica, A. Nardi, C. Castellano, N.M. Pagliuca, A. Marchetti, L. Miconi, S. Pinzi, A. Rossi, L. Arcoraci, B. Cantucci, A. Lisi, A. Sciarra, L. Pizzino, S. Spadoni, C. Thermes, M.T. Mariucci, R. Tardini, M. Pirro, M.G. De Caro, S. Monna, T. Sgroi, A. Smedile, M. Pastori, B. Castello, V. Lauciani, D. Latorre, A. Bono, M. Quintiliani, S. Pintore.
Collaborators: L. Improta, L. Margheriti, L. Scognamiglio, P. Baccheschi.
The review by BSI analysts of the seismic activity recorded in Italy from May 1 to August 31, 2022, covered all earthquakes with a magnitude of M≥1.5, while the parameters for earthquakes with a lower magnitude were calculated in real-time in the seismic monitoring room in Rome. The strongest earthquakes (M≥3.5), and a few others of particular interest [see Marchetti et al., 2016, DOI: 10.4401/ag-6116], were reviewed by BSI analysts, on average within 24 hours of their occurrence.
In the second four months of 2022, the strongest seismic event in Italy occurred on August 21 in the province of Agrigento, with a Mw of 4.1, while on June 9, an earthquake with Mw=4.0 was recorded off the coast of the Marche region. Additionally, there were 10 other seismic events with M≥3.5, including those in the province of Florence on May 3 and 12, both with Mw=3.7, and the one on May 17 in the province of Campobasso (ML=3.7).
doi: 10.13127/BSI/202201
L. Scognamiglio, S. Pintore, L. Colini, A. Sciarra, L. Pizzino, A. Malagnini, M. Pastori, A. Smedile, M.G. De Caro, C. Montuori, P. Battelli, M. Berardi, C. Melorio, G. Modica, A. Nardi, C. Castellano, N.M. Pagliuca, A. Marchetti, L. Miconi, S. Pinzi, A. Rossi, L. Arcoraci, A. Battelli, B. Cantucci, D. Cheloni, A. Lisi, G. Mele, V. Misiti, S. Spadoni, R. Tardini, C. Thermes, A. Frepoli, M.T. Mariucci, S. Monna, T. Sgroi, A. Smedile, B. Castello, V. Lauciani, D. Latorre, A. Bono, A. Mandiello, M. Quintiliani.
Collaborators: L. Improta, L. Margheriti, P. Baccheschi , M.G. Ciaccio.
The review by the BSI analysts of the seismicity recorded in Italy from January 1 to April 30, 2022, covered all earthquakes with magnitude M≥1.5, while the parameters of earthquakes below this threshold were calculated in real-time at the seismic monitoring room in Rome. The strongest earthquakes (M≥3.5), and a few others of particular interest [see Marchetti et al., 2016, DOI: 10.4401/ag-6116], were reviewed by the BSI analysts, typically within 24 hours of their occurrence.
During the first four months of 2022, 6 events with a magnitude of 4.0 or greater were recorded in Italy. Two of these occurred along the southwestern Calabrian coast (January 20 and March 4) with magnitudes Mw=4.3 and ML=4.1, respectively. On March 29, an earthquake with ML=4.0 occurred in the southern Tyrrhenian Sea at a considerable hypocentral depth (approximately 400 km), while on April 15, an event with Mw=4.2 occurred in the southern Ionian Sea. Finally, two events with magnitudes ML=4.0 and Mw=4.2 occurred in the Emilian Po Valley plain on February 9. Additionally, a Mw=5.5 earthquake occurred in Bosnia on April 22 triggered a brief seismic sequence.
L. Arcoraci, A. Battelli, P. Battelli, M. Berardi, B. Cantucci, C. Castellano, B. Castello, D. Cheloni, M.G. Ciaccio, R. Di Stefano, L. Improta, D. Latorre, A. Lisi, A. Marchetti, L. Margheriti, M. Michele, C. Montuori, A. Nardi, N. M. Pagliuca, L. Pizzino, T. Sgroi
In November 2022, a seismic sequence occurred in the offshore area of Marche, approximately 29 km from the coast and the town of Fano. The sequence began on November 9 (06:07:25 UTC) with an earthquake of ML =5.7 (Mw=5.5 calculated by TDMD, after Scognamiglio et al., 2006), immediately followed (06:08:29 UTC) by an earthquake of ML =5.2 located about 8 km south. These two main shocks triggered a seismic sequence with approximately 400 aftershocks during the first week, 13 of which had ML≥3.5 (see adjacent figure).
Within hours of the main shock, the BSI (Italian Seismic Bulletin) working group began analyzing the arrival times of P and S phases and the amplitudes of waveforms for earthquakes with ML ≥3.5, recorded by the Italian National Seismic Network (RSN), improving the accuracy of locations and magnitudes provided for rapid communication by the INGV Seismic Surveillance Room in Rome to the Italian Civil Protection (Department of Civil Protection, DPC). Afterwards, the BSI working group analyzed the seismic sequence during its initial weeks, revising hypocentral parameters of over 500 earthquakes.
D. Latorre and Bollettino Sismico Italiano Working Group*(L. Arcoraci,
A. Battelli, P. Battelli, M. Berardi, B. Cantucci, C. Castellano, B. Castello, D. Cheloni, M.G.
Ciaccio, R. Di Stefano, L. Improta, A. Lisi, A. Marchetti, L. Margheriti, M. Michele, C.
Montuori, A. Nardi, N. M. Pagliuca, L. Pizzino, T. Sgroi). (2022).
What we can say (or not) about the seismic sequence of the November 9th, 2022, Mw 5.5,
earthquake in the Marche offshore: an analysis of the Italian Seismic Bulletin on phase
interpretation, velocity models and uncertainties of earthquake locations.
GNGTS-41°Convegno Nazionale 7 – 9 febbraio 2023 (abstract) http://hdl.handle.net/2122/16494
n. 176 Bollettino
Sismico Italiano 2015
Rosalba Di Maro, Luca Arcoraci, Patrizia Battelli,
Michele Berardi,
Corrado Castellano,
Barbara Castello,
Diana Latorre, Alessandro
Marchetti,
Lucia
Margheriti, Francesco Mariano Mele, Anna Nardi, Antonio
Rossi
https://doi.org/10.13127/qdg/176
A scientific series is periodically published In the journal "Quaderni di Geofisica by INGV
(Istituto Nazionale di Geofisica e Vulcanologia); each article describes the seismicity recorded
in Italy for a specific year, based on the analysis conducted by the Italian Seismic Bulletin
(BSI) group.
The article typically includes the names of the analysts for the year in
question, a description of the state of activity of the National Seismic Network along with a
table of operational stations, a description of the dataset in terms of the number of
earthquakes recorded and analyzed, the completeness magnitude and its temporal variation.
The
core of the contribution focuses on identifying seismic sequences that occurred during
that year
(described with detailed seismicity maps), as well as chapters discussing diffuse and
anthropogenic seismicity.
In 2015, Italy experienced over 15,000 seismic events. The strongest earthquakes were 15 in
total, with magnitudes ranging between 4.0 and 5.0, six of which were deep and all occurred in
the southern Tyrrhenian Sea.
Among these 15, an earthquake with ML = 4.0 (April 24) was located between the provinces of
Ravenna and Forlì-Cesena, followed by a sequence of over 80 aftershocks. On August 3, an
earthquake of ML = 4.0 occurred between the provinces of Cosenza and Catanzaro, south of the
Sila altiplano, followed by a sequence of over 80 low-magnitude aftershocks. On December 6, two
earthquakes of Mw = 4.2 and Mw = 4.4 occurred, both in the Adriatic Sea, north of the Tremiti
Islands. Subsequently, several events with magnitudes between 3.5 and 4.0 occurred in the same
area, forming a real seismic sequence that lasted a few days.