- © Seismological Society of America
Though the Calabrian arc is the most seismic area of the Italian peninsula, the overwhelming majority of M>6.5 earthquakes have occurred during the last four centuries. Conversely, the Italian seismic catalog exhibits an almost total absence of earthquakes—even moderate‐magnitude earthquakes—between the eleventh and sixteenth centuries. The reason for this anomalous distribution of seismicity can be partially accounted for by the lack of historical sources caused by a paucity of local archives and by the enduring isolation of local administrations. We focused our research on moderate‐magnitude earthquakes of central‐northern Calabria between the sixteenth and eighteenth centuries and performed systematic research in many repositories, including in the Archivio Segreto Vaticano, in the state Archives of Naples, Catanzaro, Cosenza, and Potenza, and in several historic libraries. We found 15 previously unknown earthquakes for which we provide the level of shaking and the indication of the epicentral area for the first time. Also, we could definitively categorize one further event as a landslide rather than an earthquake. Finally, we found new evidence and information about four seismic events already known in the seismological literature; in particular, we provide a new intensity map and an increased magnitude (M 6.0) of the 14 July 1767 earthquake. Besides the new data on the earthquakes, we provide general clues and hints for searching useful documents to study earthquakes in the historical context of the sixteenth–eighteenth centuries.
The Calabrian arc (southern Italy) is the most seismic area of the Italian peninsula, as testified by the Italian Seismic Catalog (see Data and Resources), and it contained the strongest seismicity of the Calabria region in the time range between the seventeenth and twentieth centuries (Table 1; Fig. 1). At the same time, the catalog exhibits an almost total absence of earthquakes—even moderate‐magnitude earthquakes—between the eleventh and sixteenth centuries (see also Galli and Scionti, 2006; Scionti et al., 2006; Tertulliani and Cucci, 2014). The catalog for the Calabria region seems to be affected by some incompleteness for intermediate magnitudes of M 4.5–5.5 (Jenny et al., 2006). For instance, about one‐third of the intermediate magnitude earthquakes in the period A.D. 1000–2000 is missing in the region according to the methodology described in Stucchi and Albini (2000). A quick look at the catalog confirms an almost total absence of events before 1600 and allows one to speculate that, in the period 1600–1783, a number of earthquakes could have been obscured by the attention paid to the impact of the larger and more devastating events (Castelli and Camassi, 2005; Tertulliani and Cucci, 2014).
One of the reasons for this temporal earthquake is the lack of historical sources caused by the paucity of local archives and by the enduring isolation of local administrations from the central government (Naples until 1861 and Rome thereafter); consequently, research looking for new data about historical earthquakes that occurred in Calabria is traditionally a demanding challenge.
However, the accurate reconstruction of the seismic history of a territory is a fundamental necessity to derive the seismicity rates and define the maximum magnitude as inputs into the assessment of seismic hazard. In this article, we try to improve our knowledge of the historical seismicity of the Calabria region during the sixteenth–eighteenth centuries through systematic documental research aimed at:
finding new evidence of earthquakes already recorded in the catalog;
retrieving of new accounts of known earthquakes that were discarded from seismic catalogs but should not have been;
discovering unknown earthquakes; and
redefining the size and location of the recognized events by means of a new analysis of the macroseismic intensity distribution.
We focused our research on moderate‐magnitude earthquakes of central‐northern Calabria between the sixteenth and eighteenth centuries with special attention to the above‐mentioned issue of incompleteness of the catalog. To achieve our aim, we performed systematic research in many repositories, including the Archivio Segreto Vaticano (hereafter, ASV) and the state Archives of Naples (ASNa), Catanzaro (ASCz), Cosenza (ASCs), and Potenza (ASPz), as well as in several historic libraries.
HISTORICAL OVERVIEW, REPOSITORIES, AND TYPE OF SOURCES
Though the largest Calabrian historical earthquakes have been extensively investigated by many scholars (among those are Galli and Bosi, 2003; Sandron et al., 2015; Minelli et al., 2016), the primary source of coeval information derives from a restricted selection of sources represented by a few memories, chronicles, and compilations (such as those of Recupito, 1638; Di Somma, 1641; Bonito, 1691; Fiore, 1691; Vivenzio, 1788). Those sources were the reference material of the nineteenth‐century compilers of Calabrian earthquakes, such as Salfi (1787), Arcovito (1843), and Carbone‐Grio (1884), and they were later acknowledged by the main authors of the first Italian seismic compilations (among others Capocci, 1861; Mercalli, 1883; Baratta, 1901).
To look for new information and unpublished accounts of historic Calabrian earthquakes, we focused our research on local and coeval sources, primarily archived materials such as administrative documents, notary deeds and diplomatic correspondence kept in public, private, and ecclesiastic archives. Also, we took into account the historical context in which the information about Italian earthquakes was conveyed, especially before the unification of the country, which occurred in 1861. Knowledge of the mode of operation of the administration offices is necessary to follow the flow of information after an earthquake occurrence, and indeed it is the basis for seeking useful documents to study historical earthquakes in Italy. The main focal points of information on Calabrian earthquakes during the studied period (the sixteenth–eighteenth centuries) were the administration of the Kingdom of Naples and the papal Court of the Catholic Church in Rome.
Kingdom of Naples
From the sixteenth century to the unification of Italy, Calabria was part of the Kingdom of Naples, which was a Viceroyalty of the Spanish Empire until 1734. The bureaucracy of the Kingdom of Naples had a network to permit a widespread coverage of the territory, both administrative and financial. After the occurrence of an earthquake, news flowed from the most heavily impacted localities (the epicentral area, often in a remote place), passed through the provincial capital, and finally came to Naples. Here, the news was disseminated within several administrative offices, which, after examination of the reports, often asked for feedback from the local Governor (Preside of the province). This correspondence exchange could have gone on for years before the administrative procedure was finally settled.
The administrative materials produced by the bureaucratic network of the Kingdom of Naples are now stored in ASNa. The most useful holdings for historical seismology research held by the ASNa are
the Regia Camera della Sommaria, which was the principal administrative body of the Kingdom of Naples and dealt with every administrative, jurisdictional, and fiscal affair. It was subdivided into many sections (series);
the Consiglio Collaterale for the Viceroyalty and Government activity, later reconstituted (in 1734) as the supreme jurisdictional body by the Real Camera di Santa Chiara. Both of those holdings included many series;
the Segreteria dei Vicerè (Viceroyalty Secretariat), which dispatched to the other offices orders and deeds on behalf of the Viceroy; and
the Segreteria di Stato d’Azienda (State Secretariat), which collected the pleas and petitions concerning assets and public finance, including earthquakes.
Among the documents that reached the administrative bodies of the Kingdom of Naples after an earthquake occurrence, there were pleas from the inhabitants of damaged localities asking for exemptions from taxes and requests for refunds for the damage suffered by the community or by individual inhabitants. Such demands could be accompanied by accounts or descriptions of the earthquake’s effects. Less frequently, it is possible to retrieve realistic descriptions of seismic events in the diplomatic correspondence, which can be very helpful inasmuch they were written in a less bureaucratic language than the requests of financial assistance. Unfortunately, the documents concerning an individual earthquake are never filed together, but instead they are dispersed in different holdings, making a systematic scanning of a huge amount of material necessary to uncover the full earthquake record.
Parts of the administrative records of the Kingdom of Naples were also stored in the archives of the provinces that at that time were under the jurisdiction of Naples, in our case the cities of Catanzaro, Cosenza, and Potenza. Besides the administrative correspondence with the capital, those archives also contain notarial holdings. These holdings are potentially useful (Guidoboni and Ebel, 2009) as they may preserve testimonies of the occurrences of earthquakes in several forms: descriptions of damage and restoration of buildings on the occasion of sale or concessions deeds or just a simple registration of the earthquake occurrence. Even public acts in memory of the event, such as processions and votive candle offerings, may have been registered by the notary. Of course, the systematic investigation of notary holdings is an extremely difficult task because of their immense quantity.
The official documents of the Kingdom of Naples were written in several languages: most of the administrative documentations are in Spanish and/or in Italian, the latter most frequently used for the documents coming from the provinces and for many diplomatic correspondences. Other documents, for example, notary deeds and some others, may have been written in Latin, which was sometimes used for some official documents.
Roman Catholic Church Organization
Another important source of documents about the earthquakes is internal to the Catholic Church (here considered an institution and state organization). Before the unification of Italy, the Catholic Church ruled a large part of the Italian territory and kept diplomatic relationships with other states. Besides the direct administration of its own territory, the Catholic Church established a kind of specific administration through a widespread network of dioceses and parishes well beyond its own political borders. This structure worked as a parallel government body, administrating the goods of the Catholic Church (see Pasztor, 1970; Castelli, 1993; Guidoboni and Ebel, 2009). The papal Court documents are stored in the ASV in Rome, which preserves material from 1198 onward. The ASV has a very peculiar general inventory, which is the result of the way it was formed and then altered during centuries of changes and duplication of offices introduced by the popes. Consequently, the research within the holdings of the Catholic Church is often very difficult and time‐consuming.
The most important holdings of the ASV for research on Calabrian earthquakes from the sixteenth to eighteenth centuries are the following:
Segreteria di Stato (State Secretariat). This holding includes a very important series: the Nunziatura (Nunciature), in which one finds the material produced due to interactions between the State Secretariat and nuncios. In our case, of much importance is the correspondence of the nuncio of Naples, who was the diplomatic delegate to the Kingdom of Naples, with the Secretary of State; Avvisi, Memoriali, and Biglietti (letters, notes, newsletters, and gazettes) is a collection of reports; Vescovi and Prelati (Bishops and Prelates) is a series that collects letters from bishops and other important people to the Secretary of State. Within these series, one can find information about earthquakes in letters or reports from the nuncio or other prelates.
Congregatione pro executione et interpretatione concilii Tridentini (Congregation of the Council). This congregation had the task of handling the relations between the Curia and the dioceses. Every three years, each bishop was required to send a report on the general state of his diocese to the Congregation of the Council. The collection of these reports constitutes the series of the Relationes Dioecesium. These reports, in addition to describing the spiritual state of the diocese, recorded its material needs such as, for instance, the urgency to repair buildings damaged by an earthquake.
The other great repository of the Catholic Church is the Biblioteca Apostolica Vaticana (Vatican Library; hereafter, BAV) that preserves an immense quantity of manuscripts, books, prints, and other sorts of materials and important archival sections. In the Prints section, it is possible to find reports or letters devoted to seismic events.
In addition, useful documents are still conserved in the archives of individual dioceses, which keep documents from the parishes that they oversee. Concerning this last source of data, we performed a systematic scanning of the archives of all dioceses in the area of our research.
Most of the Vatican documentation of the time is written in Latin, which even today is still the official language of the Catholic Church. In addition, there also are some letters, avvisi, and various correspondence in the Diocesan archives that are written in Italian.
Along with the archives and offices described above, research was conducted at several other archives, such as the General Archive of the Cappuccini Order, and some municipal archives and a private archive in Calabria.
Figure 2 shows a map with the distribution of all the repositories visited during our research. As a general note, unfortunately, a nonnegligible subset of the documents potentially reachable in the archives was badly stored and/or is no longer available due to destruction and losses suffered during the centuries. Indications, information, or simple traces have been retrieved in diaries or memories by Calabrian scholars (coeval or subsequent) held in libraries in Rome or in the Calabrian territory. Those are important sources of information because they describe in detail the history of limited portions of territory, such as single localities or provinces, and often report the occurrence of earthquakes. The more important sources of this kind are the Calabria Illustrata (Fiore, 1691) and the memorial manuscript written by Moio and Susanna from 1710 to 1769 (Moio and Susanna, 18th century).
Finally, and much less frequently, traces commemorating earthquakes can have the form of a memorial plaque on a wall, of a statue, or of an inscription on a lamp or a bell. In our research, we found some examples of such sources (Fig. 3).
OUTCOME OF THE RESEARCH
During the research, we found documentary materials pertaining to many Calabrian earthquakes, both previously known and unknown. Here, we only present those earthquakes for which new information clearly improved our knowledge of their source location and shaking effects. In Table 2, we show a list of the studied earthquakes along with the type of historical sources and the associated number of documents retrieved in the repositories. We also include in Table 2 a number of earthquakes for which the documentary information retrieved is not considered sufficient to be summarized in the main text.
In the following is a descriptive list of the unknown earthquakes that we discovered, with the indication about the possible date and epicentral area and about the effects on the territory. Though most of the events are still poorly documented, they were completely unknown before. Except for the 1767 earthquake, and because the information about the effects do not provide diagnostics from which intensity can be estimated (for instance, how many buildings were damaged), we decided to use an alphabetic code to indicate a generic level of shaking: F, felt; HF, highly felt; SD, slight damage; D, damage; HD, high damage. The indication of the epicentral area is the most probable on the basis of the descriptions; in any case we indicate in brackets a level of uncertainty: low or high. A question mark (?) means a large uncertainty in the date of the earthquake. All the localities cited in the following are plotted in Figure 2.
25 February 1674, Crotone Area (L), HD
A number of Relationes (available in ASV) written by the bishop of Cerenzia and Cariati between 1678 and 1687 (ASV, 1678–1687) describe an earthquake that caused heavy damage to the cathedral, the bell tower, and the episcopal palace in the village of Cerenzia in the night between 24 and 25 February 1674. The bishop first repaired the church, then the other buildings. Unfortunately, research seeking the effects in the surrounding villages has been unfruitful so far. Anyway, we consider the occurrence of the event as undeniable because the coeval sources are official and authoritative.
September 1682, Calabria (H), SD
The Vatican nuncio from Naples (ASV, 1682) wrote in a letter of 15 September 1682: “it is reported from Calabria that a fearful earthquake occurred there, without any other damage besides some houses, and that a fountain […] in the city of Paola, suddenly dried up.” As Paola is located on the western coast of Calabria, we can suppose that a moderate event occurred along the Tyrrhenian side of the Peninsula and caused widespread slight damage.
18 November 1687, Central Calabria (L), HD
From an extensive correspondence between the nuncio of Naples and the bishop of Belcastro (ASV, 1692a) and a report on the state of the diocese, written from July 1692 to November 1692 (ASV, 1692b), we infer that the pope granted alms to repair the damage caused by an earthquake that occurred at least four years before. In Belcastro, damage was suffered by the cathedral, the bell tower, the episcope palace, and some houses. No document records the date of the earthquake. A careful reading of the letters provides clues to delimit the occurrence of the earthquake between November 1687 and May 1688, during the Sede Vacante (Vacant Seat, i.e., the period of time between the death of a bishop and the appointment of the successor). This would justify the delay in the concession of the funds requested for the damaged villages of Belcastro, Andali, Cropani, and Coturella.
In the chronicle by Moio and Susanna, written from 1710 to 1769, is recorded “a large earthquake shaking on November 18, 1687; in Catanzaro no heavy damage, but in the surrounding of Chiaravalle ruins were heard to have occurred.” In our opinion, the 18 November earthquake could be the event that damaged Belcastro and surroundings.
September (?) 1691, Crotone Area (L), D
This earthquake is inferred from a report by the bishop of Crotone (ASV, 1692c), in which he stated to have repaired the episcopal palace damaged by an earthquake that occurred the previous year (1691). Furthermore, the nuncio of Naples indicates in a letter of 18 September 1691 (ASV, 1691) that, in that period, frequent earthquakes occurred in the Calabria region.
February–May 1697, Catanzaro Province (H), D
Several sources record earthquake occurrences in Calabria between February and May 1697. The first earthquake is on 20 February (Capocci, 1861); afterward, a letter of 5 March by the nuncio of Naples and news from Moio and Susanna (18th century) record a strong shaking that occurred on 13 March with heavy damage in Catanzaro province. The seismic sequence continued until May.
April 1703, Western Calabria (H), HF
In a letter on 10 April by the Vatican nuncio from Naples (ASV, 1703), “we had the advice from Calabria that this plague (the earthquake) is continuously felt, and more frighteningly in the city of Tropea, where almost all the inhabitants, scared, sought refuge in the countryside.” In the same year, Moio and Susanna (18th century) state that an event was felt in Catanzaro.
October–November 1706, Cosenza (L), D
In two correspondences from Naples (9 and 13 November) by the Corriere Ordinario (ASV, 1706), a strong shock is reported to have caused damage in Cosenza at the end of October. Capocci (1861) reports that other strong shocks occurred on 3 November.
22/23 March 1707, Catanzaro District (L), HD
In the Rotterdam Gazette of 2 May, it is reported in a correspondence from “Naples 5 April, on 23 of the previous month a terrible earthquake occurred in Calabria, which ruined the small city of Catanzaro and many neighboring villages.” The Amsterdam Gazette of 6 May reports, “Naples 16 April, we learn from Messina that last 22 (March) a large earthquake occurred, with great fear, but little damage.” Both gazettes have been found in the ASV, State secretariat holding (ASV, 1707). This event is well constrained, with heavy damage in Catanzaro and surroundings and slight damage in Messina, about 100 km apart.
March 1733, Earthquake Classified as Landslide
The case of the Casabona event of March 1733 is an intriguing one. The original information comes from the work of Pesavento (1991), who cites the destruction of the village of Casabona from sources of the ASCz. This account is confirmed by two coeval sources of Calabrian history that described the earthquake: Aceti (1737) and an anonymous author of the eighteenth century, who wrote a note on the Martire manuscript (seventeenth century). Starting from this news, we looked for other references in which we expected them: ASNa and ASV. No documents with information about this earthquake were retrieved in the holdings of the ASV, whereas two documents from Regia Camera della Sommaria (Archivio di Stato di Napoli [ASNa], 1733a,b]) provided accounts of the destruction of Casabona following an earth movement. The word “earthquake” is never cited. The absence of accounts about other localities nearby Casabona (that was reported as completely destroyed) has led us to speculate that the heavy effects observed in that village were due to a localized geomorphological phenomenon. Indeed, recent historical and geological studies (Pellizzi and Tallarico, 2003; Cozza, 2014) have definitely demonstrated that the destruction of Casabona was caused by a huge slumping, and the warning signs of this potential slump were recognized during prior decades.
The following events are found in the traditional seismological literature. In particular, the 1687 and 1767 earthquakes are classified in the catalogs, whereas the documentary information available before our research for the 1614 event was considered insufficient; therefore, this event was not included in the modern seismic catalogs.
24 November 1614, Crotonese (H), HD
The earliest account for this event comes from Fiore (1691): “In the year 1614, on 24 November, at four in the night, dreadful earthquake.” Moio and Susanna (18th century) probably acknowledged the account and integrated it: “In the year 1614, on 24 November, at four in the night, a terrible and dreadful earthquake occurred, that caused a lot of damage in the province. In Catanzaro, by the grace of God no substantial damage occurred.”
A recent retrieval (Pesavento, 1997) in the Libro dei Morti (Dead register) of the Diocese of Crotone highlights a remarkable increase in the number of dead in Crotone during the month of November 1614. This sudden peak of mortality (34 in October, 70 in November, and 29 in December) could be linked to the earthquake occurrence. A supplementary investigation could be very useful to better define the knowledge of this earthquake.
September 1687, Capo Vaticano Area (L), D
A new source from the nuncio of Naples in a letter of 7 October (ASV, 1687) confirms the occurrence of the event, with damage to many houses in Tropea.
14 July 1767, Crati Valley, I 9
The 14 July 1767 earthquake is currently included in the CPTI (see Data and Resources). The most recent study, Guidoboni et al. (see Data and Resources), estimates that the event had a maximum intensity of 8–9 Mercalli–Cancani–Sieberg (MCS) and seven macroseismic points.
During our research, other accounts were retrieved (Table 3), including localities not quoted in Guidoboni et al. (see Data and Resources). Very interesting is the unpublished anonymous report retrieved from BAV (1767) that records the damage in Bisignano: “it is reported from Bisignano that the cathedral is in part collapsed, and there was noteworthy damage in the houses, but thanks to the God’s mercy, only a few people died….” In the reports of the Cosenza Bishop (ASV, 1772, 1776), the earthquake is reported at Cosenza, Castiglione Cosentino, and the village of Altavilla, the last of which is described as “extensively damaged by the earthquake, where nothing can be seen but ruins….” Coeval accounts recorded 47 victims and many injuries.
In some documents retrieved from ASNa, in the Regia Camera della Sommaria holding (ASNa, 1767a,b,c,d,e,f,g,h), we found new information about damage in localities such as Cosenza, Castiglione Cosentino, Luzzi, Rose, and Roggiano Gravina. In a public act by the Pietrafitta commune from Archivio di stato di Cosenza Fondo Comuni (ASCs, 1767), we can infer that the village did not suffer damage, but the earthquake did cause a general alarm, inducing the inhabitants to ask for the intervention of the Virgin and increasing the annual alms to the church named after her. We found the same kind of clues in other localities where thanksgiving rituals devoted to the Virgin or to some important saint (Amato, 1884) or collective penance rituals (processions, collective prayers, and particular liturgies) connected to the 14 July 1767 event are still present in the popular tradition. We found these anthropological traces in at least five localities around the area hit by the earthquake. In some cases, such traditions are materialized by means of statues, memorial stones, or inscriptions. The collective rituals for surviving the earthquake in some localities indicate that the earthquake generated alarm and concern. From the macroseismic point of view, this means a relatively high intensity, expressible in the degree 5 of the MCS scale. Other evidences of damage to buildings in Luzzi and Bisignano have been found in documents of the Archivio Diocesano Cosenza (ADCs, 1767; ADCs, 1771). In Amantea, the shock caused slight damage, interrupting the restoration work in the castle (Turchi, 2002). The earthquake was felt over large distances, as far as Reggio Calabria and Gallipoli (around 150 km epicentral distance), as reported in Vitriolo (1840) and Perrey (1848).
These new accounts improve the general knowledge of the event, allowing us to increase the number of localities that we know were hit by the earthquake from 7 to 17 (see maps in Fig. 4) and to reassess the intensity values. We also calculated the macroseismic magnitude and the epicentral coordinates by means of the code Boxer (Gasperini et al., 2010; Table 3). A tentative macroseismic source is proposed on the basis of the intensity points of the event (Fig. 4). This north–south‐striking seismogenic fault substantially parallels the source inferred also by geological and geomorphological observations by the DISS Working Group (see Data and Resources), except for the enhanced dimensions due to the increased magnitude.
The methodical scrutiny of many holdings of historical archives produced interesting results concerning the seismicity of the sixteenth–eighteenth centuries in central‐northern Calabria. In particular, 15 unknown earthquakes have been recognized, 8 of which with probable damage documented (see Table 4).
During the research, we found new accounts for four known earthquakes. In particular, we significantly improved the knowledge of the 14 July 1767 earthquake, for which we provide more constrained epicentral parameters because the number of intensity points increased from 7 to 17.
Beyond the above results, we want to stress some questions about the historical research of earthquakes. Although these questions stem from the Italian case study, we suggest that they can be extended to all the countries that have written records that extend back many centuries.
The systematic screening of archival material is the only way to retrieve unpublished accounts concerning historical seismicity, both of known and of unknown earthquakes, and to improve estimates of their source locations and shaking effects. Nevertheless, we are aware that research, though accurate, will never be conclusive due to the low abundance and spread of documentation in different archives, especially in Italy. Many similar studies must be replicated in time to have a chance of retrieving new documentation.
This type of research must be necessarily conducted after an analysis of the historical and administrative context of the country hit by the seismic event. In our case, for instance, the present Italian territory during the period of our study was divided into many states, and each state left documentation organized pursuant to its own state organization.
The Kingdom of Naples and the Catholic Church were two of the greatest producers of administrative documentation from the fifteenth to nineteenth centuries in Italy, and yet they had a very different organizational structure and administrative network. For studies on historical seismicity, the information network of the Catholic Church proved to be more profitable than that of Naples, as the former provided accounts related to 12 earthquakes and the latter only to two earthquakes. The most probable reason for this fact is a difference in the attention to conservation of the documents and in a possible dissimilar approach to information gathering by the public officials.
We stress the need of a close collaboration between seismologists and historians in investigations on historical seismicity to focus the expertise of each discipline toward the most fruitful results.
DATA AND RESOURCES
The DISS Working Group (2015). Database of Individual Seismogenic Sources (DISS), Version 3.2.0: A compilation of potential sources for earthquakes larger than M 5.5 in Italy and surrounding areas is available at http://diss.rm.ingv.it/diss/ (last accessed November 2016), Istituto Nazionale di Geofisica e Vulcanologia; doi: 10.6092/INGV.IT‐DISS3.2.0. Guidoboni, E., G. Ferrari, D. Mariotti, A. Comastri, G. Tarabusi, and G. Valensise (2007). CFTI4Med, Catalogue of Strong Earthquakes in Italy (461 B.C.–1997) and Mediterranean Area (760 B.C.–1500). INGV‐SGA is available at http://storing.ingv.it/cfti4med (last accessed November 2016). Rovida A., M. Locati, R. Camassi, B. Lolli, and P. Gasperini (Editors) (2016). CPTI15, the 2015 version of the Parametric Catalogue of Italian Earthquakes. Istituto Nazionale di Geofisica e Vulcanologia, doi: 10.6092/INGV.IT‐CPTI15.
We are in debt to Viviana Castelli for her translation of many documents from Latin. We are also in debt to Editor John Ebel and an anonymous referee, who contributed to major improvements in the article. We also wish to thank the patience and kindness of all the archivists who supported us in our search for original material. This study benefited from funding provided by the Italian Presidenza del Consiglio dei Ministri–Dipartimento della Protezione Civile (DPC). This article does not necessarily represent DPC official opinion and policies.
In the course of the research, we examined hundreds of archive documents and tens of historical sources, not all of them with positive results, and several of them with repetitive accounts but several others with unique and original information. As it is impractical to provide an exhaustive list of all sources that were examined, we only cite those we consider essential to the comprehension of the article.