- © 2014 by the Seismological Society of America
The Italian seismic catalog (Rovida et al., 2011) portrays a significant gap of seismicity in the Pollino Range area, the southernmost segment of the southern Apennines at the boundary with the Calabrian arc. In this region, the only significant seismic event of the instrumental era occurred in 1998 north of the Pollino Range (Mw 5.6, Fig. 1). No seismic event with intensity greater than VIII on the Mercalli–Cancani–Sieberg (MCS) scale is present in the historical records, whereas strong earthquakes occurred immediately north (1836 M 6.0; 1857 M 7.0) and south (1184 M 6.7; 1836 M 6.2) of the area (Fig. 1). However, geologic data (Bousquet, 1973; Russo and Schiattarella, 1992) have shown clear evidence of Quaternary faulting along two major normal seismogenic faults, the Pollino and the Castrovillari faults. Paleoseismological data (Michetti et al., 1997; Cinti et al., 1997, 2002) recognized the occurrence of large magnitude events during medieval times along those two faults, but no trace is left of these major events in the historical record.
In the case of the Pollino area, the discrepancy between true seismic history and recorded seismic history is due to a combination of a documentary gap of the historical sources (Scionti et al., 2006) and to the low population and scarcity of settlements in the epicentral area (D’Addezio et al., 1995; Cinti et al., 1997). Furthermore, there is the sound possibility that such documentary limitation also might affect moderate (M 5–6) earthquakes, thus providing the opportunity for new assessments that could re‐estimate their sizes. Noticeable recent examples of this come from Scionti et al. (2006), with the re‐estimation to Mw 6.2 of an earthquake that occurred 100 km southeast of the Pollino region, from Tertulliani et al. (2012) for the 1762 earthquake close to L’Aquila, and from Azzaro et al. (2007) for northeastern Sicily. We want to emphasize that there is recent growing interest in the question of re‐estimating the sizes of historical earthquakes (see Rong et al., 2011; Hough, 2013). Therefore, reducing the uncertainties in the locations and sizes of seismic events for areas like Pollino can be an important contribution toward a clearer picture of the seismic potential and the distribution of earthquake recurrence times that can affect the seismic hazard of a territory.
The first attempts at in‐depth analyses of the historical seismicity in the Pollino seismic gap date back to the first half of the 1990s (Storia Geofisica Ambiente [SGA], 1994; Valensise et al., 1994; Guidoboni and Mariotti, 1997), whereas more recent developments are by SGA (2000), Camassi and Castelli (2004), and Castelli and Camassi (2005). The seismic histories (the list of earthquakes affecting a site during historic time) of towns and villages of the area (Locati et al., 2011) do not contain earthquakes that occurred before A.D. 1600, neither local nor remote, which could have affected such localities. The oldest traces of earthquakes are associated with the 1638 M 7 event that occurred in central Calabria ∼100 km south of the Pollino area and produced damage in Castrovillari. The more ancient event documented in the study area is the 1693 earthquake, which was listed for the first time in a catalog in 2007 (Guidoboni et al., 2007). In this study, we focus on this latter event, which also appears as the strongest shock in the region and is characterized by a relative scarcity of information and few intensity datapoints. We gathered all potential primary sources of information available for the 1693 earthquake in the attempt to improve its intensity map. We also address two further issues in the reappraisal of the 1693 earthquake: (1) the temporal coincidence between 8 January 1693 Pollino earthquake and its aftershocks and 9–11 January 1693 catastrophic earthquakes of eastern Sicily, along with the consequent quest for a correct attribution of the information regarding the two seismic sequences; and (2) the occurrence in October 2012 (following a sequence of small earthquakes lasting three years) of an Mw 5.3 mainshock, which is by far the strongest event in the instrumental era in the area.
REPOSITORIES AND SOURCES
The research of new documentary sources on 8 January 1693 earthquake started with a detailed exploration of the documents available in the previous literature, in particular the technical reports of SGA (1994 and 2000) and the Catalog of Strong Earthquakes in Italy (461 B.C.–1997) and Mediterranean Area (760 B.C.–1500) (CFTI4Med; Guidoboni et al., 2007) and references therein. The main source for this earthquake was the “Storia di Oriolo by Giorgio Toscano” in the transcription of Basile (1978), from which all studies started.
SGA (1994, 2000) reports the transcription of some other accounts and coeval sources that are limited to only four localities (Fig. 2a): Castrovillari, Mormanno, Morano Calabro, and Oriolo. Other documents were quoted in CFTI4Med (Guidoboni et al., 2007), which adds another four localities (Fig. 2b) to the intensity data set (Cassano, Cosenza, Monteleone [nowadays Vibo Valentia] and Scalea). Unfortunately, the transcriptions of the texts of CFTI4Med are not available, so we retrieved the original documents in the repositories where they are still kept. The most recent re‐examination of the earthquake reports (Camassi et al., 2011), adding only the locality of Saracena, did not provide much advancement in the state of the knowledge concerning the event (Fig. 2c).
Research about a seventeenth century earthquake is mainly concerned with archival sources, especially administrative or diplomatic correspondences and private letters. In this kind of investigation, it is necessary to not disregard the historical context in which the information was conveyed. At the end of the seventeenth century, the Pollino area was part of the Province of Calabria Citra (or Citeriore) (northern Calabria) of the Kingdom of Naples. This latter was a Viceroyalty of the Spanish Empire, where most of the documentation of administrative affairs was dispatched. In addition, a large part of the documentation belongs to the diplomatic correspondence among the Kingdom of Naples and the governments of other Italian states, such as the Venice Republic, the Grand Duchy of Tuscany, and the papal Court in Rome. In particular, a most important source of information about the earthquake turned out to be the documentation between the Kingdom of Naples and its motherland, Spain.
Another source of documents about the earthquake is internal to the Catholic Church, in particular the correspondence between the Roman Curia and nuncios and between the local dioceses and parishes. The main center of the ecclesiastical administration in Calabria Citra was Castrovillari, the seat of the bishop of the Cassano diocese. Concerning this latter source of data, we performed a systematic scanning of all parish archives of the area. On the basis of the aforementioned network of relationships, we carried out research in many archives, including the Archivio Segreto Vaticano and the state Archives of Florence, Venice, Naples, and Cosenza.
A secondary group of documents that might contain earthquake reports are the early journalistic sources, gazettes, or notices that, working like a modern press agency, publicized accounts and news from the main European cities (Castelli and Camassi, 2005). However, this secondary group of documents generally provided only vaguer and less elaborated news. Finally, many historiographic studies in public and private libraries were examined. The most important of these was the retrieval of the original manuscript of Toscano (1695) in a private library. A complete review of this research path, of its sources, and of the documents examined is published by Tertulliani and Cucci (2014).
DEFINING THE POLLINO SEQUENCE THROUGH THE COEVAL SOURCES
As already outlined in the Introduction, the Pollino earthquake of 8 January 1693 is among those events that have been obscured by other major earthquakes that occurred very close in time and space. In this case, on 9 January 1693, there was the beginning of a destructive seismic sequence in eastern Sicily that left a major impression in the collective imagination and affected most of southern Calabria as well (Adler, 1983; Gutscher et al., 2006; Visini et al., 2009; Locati et al., 2011; and references therein). We believe that discriminating between the two sequences is the first step toward a reliable assessment of the size and temporal extent of the Pollino sequence.
The most important source of information concerning the seismic sequence at Pollino comes from the memory of Toscano (1695); he describes the mainshock in detail as an eyewitness. The other sources are letters and diplomatic correspondences written from some days to some weeks after the event. In most of such documents, including the history of Toscano, it is difficult to distinguish the information associated with each individual event because of the belief at the time that only one earthquake was responsible of all the observed or reported effects.
Toscano indicates three different damaging shocks in Oriolo, which occurred in the night of 8–9 January (Thursday–Friday; Table 1). Approximately, the same hours for the earthquakes are indicated in two letters sent from Naples to Florence and to Venice, which describe the earthquakes in Castrovillari. Another damaging shock is reported by Toscano to have occurred during the night of 22 January (23 January, 01:00 GMT), confirmed in a letter sent from Castrovillari to Naples on 28 January. The hours indicated in the sources and shown in Table 1 were expressed in Italian time, in use at the time, and were converted using Dominici and Marcelli (1979).
The Sicilian sequence began on 9 January at 21:00 with a strong shock (M 6.2), followed by the mainshock on 11 January at 11:30 (M 7.4). Damage and perception from these events were widespread in Calabria, especially in the southern part of the region. The early accounts of the earthquakes on 8 January in Calabria and on 9 January in Sicily, dated 13 January (Archivio Segreto Vaticano [ASV]; Archivio di Stato di Firenze [ASFi], 1693), were both considered as having originated from a unique event. Indeed, in letters from northern Calabria, it is not difficult to perceive the relief of having survived the exceptional catastrophe. Toscano himself, in his description of the events, depicts Sicily as the origin of the earthquakes and the most damaged land (Toscano, 1695). However, the damage area of the Sicilian sequence has a limited extension in the Calabrian territory (Fig. 3), and the Pollino area is more than 100 km farther from the slightest effect sites of the Sicilian event.
From the descriptions from Calabria, it is very unlikely to suppose that the Sicilian mainshock could have produced damage in northern Calabria. Thus, we can reasonably maintain that the four earthquakes identified in Table 1 are the principle shocks of the Pollino sequence. Finally, from our reading of the sources, we can infer that the Pollino sequence was quite long, inasmuch the people in that area felt shocks for almost one year.
FROM THE SOURCES TO THE INTENSITY MAP
A methodical reading of all the documentary material, published and unpublished, allowed us to reappraise the macroseismic effects of the Pollino events and to assess the intensity values for 16 sites (Table 2 and Fig. 4). Damage has been recognized and documented in Castrovillari and Morano Calabro, where some churches and some houses suffered serious damage, whereas Oriolo suffered slighter damage. For the villages of Altomonte, Mormanno, San Basile, and Saracena, the sources reported “…neither the damage suffered is less in…,” but did not record further details. The information extracted from the documents is related to the whole earthquake sequence that is documented from 8 January to the end of March 1693, so the intensity is assessed on the basis of the cumulative effects of the aftershocks. In the following, we provide a description of the significant elements that we evaluated to assign MCS intensity values for each locality.
This village is the main center of the earthquake. Most of the documents and sources belong to or cite this locality, which was also the Episcopal seat of the Cassano diocese (Russo, 1967). In the dispatches among the correspondents of Venice, Florence, and Rome resident in the Naples Kingdom, Castrovillari is described as the most damaged village. In particular, after the 8 January shocks, the ruin of two parish churches, two monasteries, and some other buildings is documented (ASVe, 1692–1693). During the sequence, probably after the 22 January shock, the church of Santa Maria del Castello was also damaged (ASFi, 1693; Russo, 1982; Trombetti, 2012). In other documents, two rural buildings, properties of the San Francesco monastery, are described as completely ruined and collapsed (Archivio di Stato di Cosenza [ASCs], 1706), and damage was suffered by the cloister of Santa Chiara and by the Bishop Palace (ASV, 1701, 1704; Archivio Diocesano di Cassano allo Ionio [ADC], 1701). The assessed intensity is 7 MCS.
Together with other localities, Morano was cited by Toscano (1695) and several other documents as one of the most damaged villages, but there were no descriptions of the damage. Guidoboni et al. (2007) assessed I=8. During this research, some retrieved archival documents (ASFi, 1693; Archivio parrocchiale di Santa Maria del Gamio [Saracena; APS], 1694; Archivo General de Simancas [AGS], 1693a,b) provide more contextual news. In particular, there was notice of the collapse of the belfry of the Padri Zoccolanti church and news about much damage to hamlets in the Morano land. The assessed intensity is 7 MCS.
Altomonte, San Basile, and Saracena
These are the new entries in the list of the affected sites. They are cited together in a couple of dispatches from Castrovillari and Naples to Florence (ASFi, 1693). The three localities were described as suffering after the earthquake but without any description of damage. These accounts could explain the section of the memoir of Toscano (1695) in which he told about the most‐hit villages: “…in our Calabria: Castrovillari, Morano, Mormanno and other (villages) nearby suffered with the ruins of houses, churches and monasteries… .” Given this generic description, we assess an uncertain intensity between 6 and 7 MCS.
The main and unique source that described effects in Oriolo is the memoir by Toscano (Toscano, 1695; Basile, 1978), wherein some damage due to the earthquakes that occurred during the night of 8–9 January is reported. We found that the original manuscript of the memoir by Toscano (1695) differs from the later transcription (Basile, 1978), but so far this is the only known document about the earthquake’s effects in Oriolo. The indication “…some dome of churches ruined…” is present only in the modern transcription, whereas in the original manuscript the same sentence is “…some dome of chimneys ruined… .” The original report suggests a slighter impact of the event in Oriolo than is inferred by the modern transcription. Some damage to chimneys and a partial collapse from the tower of the castle probably best represents the picture of the effects in Oriolo. The assessed intensity is 6–7 MCS.
We did not retrieve any specific accounts of damage in Mormanno other than the generic note of Toscano (1695) and in a letter from Naples to Florence (ASFi, 1693). In Mormanno, religious ceremonies and practices performed to give thanks for the survival of the 1693 earthquake are well documented. The lack of damage accounts for Mormanno suggests the absence of significant damage (Archivio Arcipretale di S. Maria del Colle di Mormanno [AAM], 1742). The assessed intensity is 6 MCS.
In the Bishop’s relation of 19 August 1700 (ASV, 1700) the Anglona Cathedral looked “heavily damaged by the most recent earthquakes.” In this case, considering the time span and location, it is reasonable to hypothesize the 1693 earthquake as the most probable event responsible for the damage. With only a report about a single building, the assignment of D (damage to single building) is appropriate.
The monastery of Santa Maria of Colloreto is cited in coeval documents (ADC, 1722) and a parish chronicon (APS, 1694) as heavily damaged by the 1693 earthquake. Assignment of D (damage to single building) is made here.
The monastery of San Nicola of Tolentino in Pedali, near Viggianello, suffered a “very heavy damage by the earthquake” such that the friars sold two rural houses on their property to repair the damage. As the date of the document is 1700 (Archivio di Stato di Napoli [ASNa], 1700), it is reasonable to hypothesize the 1693 earthquake as the most probable event responsible of the damage. In this case, we assign D (damage to single building).
In referring to the strong Sicilian earthquake in Crono‐istoria of Corigliano, Amato (1884) says, “Corigliano was powerfully shaked, its buildings swayed, but it was safe.” This is another example of the confusion of the Sicilian and Calabrian events described previously here. In fact, given the huge difference in the epicentral distances between the earthquakes, we think that the event in this context would be the Pollino earthquake. We assess it as intensity 5 MCS.
Private letters from Scalea (dated 5 March 1693) reported a continuously felt series of earthquakes that generated some apprehension. We believe they could be aftershocks of the 8 January Pollino event. We assess it as intensity 5 MCS.
Monteleone (now Vibo Valentia)
Two letters to the Viceroy of Spain in Naples (AGS, 1693a,b) reported detailed descriptions of light shocks felt in Monteleone, beginning on 8 January 1693. We assess these reports as intensity 3 MCS.
In some correspondences from Naples (ASV, 1693) there is news of the perception of some earthquakes in Cosenza, without any damage. An assignment of F (felt) is made here.
In a letter of 13 January (ASFi, 1693), G. Berardi describes two shocks felt during the night of 9 January (Friday), oddly enough at the same hours and intensities as the shocks reported to have occurred elsewhere in the night of 9 January (Thursday). It seems credible that the author confused Thursday night with Friday night and that the letter describes the two strongest shocks that occurred in the Pollino area. A second letter quotes continuous earthquakes as occurring in Calabria Citra and Basilicata and felt also in Naples. Assignment of F (felt) is made here.
Santa Agata Esaro
A notarial deed and a document from the parliament (ASCs, 1693) report that the village was spared by a strong earthquake that occurred on 11 January (the mainshock of the Sicilian sequence). The documents also clearly refer to a pre‐existing alarm in the population due to earthquakes in the previous days. Therefore, it is plausible to link the pre‐existing alarm to more local seismicity, such as that at Pollino. We give this site an assignment of F (felt).
None of the sources we scanned cites Cassano as mentioning the 1693 earthquake, so we removed this village from the list of the localities involved in the Pollino event.
ASSESSING THE LOCATION AND MAGNITUDE OF THE 1693 POLLINO MAINSHOCK
The number of localities from which useful information about the event has been recovered has increased from 7 or 8 to 16. The maximum intensity has been reduced to 7.
We used the Boxer 4.0 code (Gasperini et al., 2010) to calculate the macroseismic magnitude and the macroseismic epicenter of the event, and we compare our results to the same parameters derived in previous studies (see Table 3). In our analysis, the macroseismic magnitude Mw of the 1693 Pollino event is considerably decreased, dropping from 5.7 (Guidoboni et al., 2007) to 5.2 in this study. Though the earthquake location does not change dramatically with respect to the location in the CFTI4Med catalog (Guidoboni et al., 2007; see Fig. 2b), we observe a slight shift (∼6 km) of the event toward the south and west, in the direction of the aftershock cloud of the recent 2010–2013 sequence (Fig. 5). The uncertainties in both the epicenter and magnitude (Table 3) for the Pollino event are comparable to the values displayed by similar earthquakes in the Italian catalog (Rovida et al., 2011).
THE 2010–2013 SEQUENCE
No M≥3.6 earthquake is recorded in the databases of Italian instrumental seismicity between 1981 and 2010 in the study area (Castello et al., 2006; Italian Seismological Instrumental and Parametric Database [ISIDe] Working Group, 2010); the seismicity appears quite rare and diffuse and does not show any significant clustering in time or space. Following this ∼30‐year period of relative quiescence, the area suddenly experienced the onset of a seismic sequence in the second half of 2010 that lasted about three years and was characterized by frequent periods of intense activity. The sequence was composed of ∼5500 shocks that occurred between July 2010 and September 2013 and culminated with an Mw 5.3 (CMT Catalog, Dziewonski et al., 1981) mainshock that occurred in October 2012 not far (∼15 km) from the estimated location of the 1693 earthquake (Fig. 5).
The focal mechanism of the 2012 shock defines a north‐northwest‐striking, west‐southwest‐dipping normal fault (Totaro et al., 2013). The geometry and kinematics of the earthquake source are in agreement with current knowledge about the seismotectonics of the region, the southern Apennines being generally characterized by approximately northeast‐trending extension (D’Agostino and Selvaggi, 2004). The 25 October 2012 mainshock was felt over a relatively wide region up to ∼200 km from the epicenter and produced slight but diffuse damage in the epicentral area (Azzaro et al., 2012; D’Amico and Scarfì, 2012), with European Macroseismic Scale 1998 maximum intensity of 6 at Mormanno and the neighboring area. In some localities east of the October epicenter, the shock worsened the damage produced by a previous M 4.3 event that occurred in May 2012 (Fig. 5).
Three main issues connected with the reappraisal of the 1693 Pollino earthquake are (1) reducing the uncertainties in the location and size of the event, (2) providing a clear distinction between the northern Calabria and the eastern Sicily sequences, and (3) reading the 1693 sequence in light of the 2010–2013 earthquakes.
Location and Size of the Pollino Mainshock
The research into the 8 January 1693 Pollino earthquake (and of the subsequent aftershocks sequence) carried out in this work retrieved a valuable amount of new documentary sources that allowed us to widen our knowledge about this earthquake. Previous studies of this seismic event (Fig. 1 and Table 3) indicated intervals of magnitude 5.3–5.7 and maximum intensity 7.5–8 for the mainshock. The historical research in this paper has contributed to a reassessment of the intensity values of some localities, to the discovery of other localities affected by the earthquake, and to an update of the entire scenario of the Pollino event. Table 2 lists the 16 localities affected by the earthquake, and Table 3 shows the new epicentral and magnitude parameters.
When we started this work, our hypothesis was that finding new information concerning the 1693 mainshock more likely would result in an increase of its magnitude rather than in a downgrading, as for example, happened in the case of the 1744 central Calabria M 6.2 earthquake (Scionti et al. 2006). In this case, the systematic consultation of many new sources of information for the 1693 earthquake led to a dramatic reduction in the estimate of its size. This finding leaves the quest of the discrepancy between true seismic history and recorded seismic history quoted in the Introduction of this work substantially unchanged: the 1693 earthquake remains a moderate‐size event that looks very much like other subsequent earthquakes that have occurred throughout the Pollino Massif area, particularly those in 1708 (Mw 5.5), 1998 (Mw 5.6), and 2010–2013 (ML 5.0, Mw 5.3). However, location and magnitude of the event now can be considered more robust than before, as the estimates of these parameters are based on a larger set of data than previously known. These data tell us that the 1693 earthquake most likely was centered on the southern side of the Pollino Massif (compare locations in Fig. 2a and c), was probably located near or on the surface projection of both the Castrovillari and the Pollino faults, and could possibly have taken place on a limited segment of either these faults.
Distinction between the Calabria and Sicily Sequences
The temporal and spatial proximity of these two sequences in southern Italy is likely the reason for the late identification of the Pollino event. The temporal coincidence muddled the first phase of news and information about the earthquakes coming from Calabria Citra, making the Pollino events later invisible in the known historical and seismological literature.
No previous studies of the seismicity of the Pollino area noted the occurrence of a seismic sequence associated with the 8 January shock in terms of size of the aftershocks and temporal extent of the seismicity. New information retrieved from this study allowed the definition of the largest shocks of the sequence in the month of January 1693. The first earthquake occurred on 8 January at about 21:00 GMT (04:00 in the night in seventeenth‐century Italian time) and provoked fear but no damage. After about two hours, the first damaging shock occurred, followed by another damaging event on 9 January at about 05:00 GMT (12:00 in the night of 8 January, Italian time). A third damaging shock occurred in the night of 22 January (01:00 GMT of 23 January). From the sources, we find that the sequence was active for at least several months and perhaps for one year and more, and it included frequent aftershocks that were large enough to alarm the population.
We believe that the new documentary sources provide a clearer picture of the succession of the events that occurred in 1693 in northern Calabria. However, in the southern part of the region affected by the Pollino sequence (especially the localities of Cosenza, Santa Agata Esaro, Corigliano, and possibly Scalea; see Fig. 4), the combination of perceptions from the Pollino and Sicily sequences is quite tangled, although this circumstance does not alter the general picture of the Pollino event that we propose in this paper. Consequently, we suggest that the northernmost limit of perception of the catastrophic Sicily events could be moved about 100 km further north than displayed by previous studies (Guidoboni et al., 2007; Locati et al., 2011).
Comparison between the Modern and Historical Pollino Sequences
Our new map of intensities of the 1693 Pollino earthquake permits us to speculate on a comparison of those earlier events with the earthquake sequence that occurred in the 2010–2013 in the same area. Similarities are evident in the sizes of the two mainshocks and in the durations of the two seismic crises.
Our new estimate of M 5.2 for the size of the 1693 mainshock makes it fully comparable with the size of the last large event that occurred in this area, on 21 October 2012, Mw 5.3 (Imax 6). This reinforces the evidence that, on the southern side of the Pollino Massif, we have direct or testified evidence (i.e., the period of completeness of the catalog in southern Italy, ∼0.5 ka for M>6) only for moderate‐size earthquakes, at a size even lower than previously believed. These observations sharpen the discrepancy between the known historic activity and the longer‐term seismic history indicated by paleoseismological data (Cinti et al., 1997, 2002; Michetti et al., 1997).
The systematic scanning of records of the 1693 event provided the most accurate picture to date of the earthquake sequence originated by the 8 January mainshock. Besides the identification of the four principal shocks that occurred in the month of January 1693, the documents shed light on quite a long sequence, which lasted about one year. In comparison, the duration of the 2010–2013 sequence exceeded three years, which makes it one of the most long‐lasting sequences in the recent history of Italian earthquakes. The long duration of both sequences may be a characteristic feature of this region that is not common to other parts of the Italian territory, especially for moderate‐magnitude sequences.
Finally, we note some differences between the 1693 and 2010–2013 sequences. The first difference lies in the maximum intensities reached by the mainshocks. As the magnitude of the two mainshocks is similar, the difference between the maximum intensities can be partially accounted for by an undoubted improvement in the vulnerability of the edifices in the area. The second difference lies in the epicentral location of the mainshocks, as they appear to have been located ∼15 km apart. Though the location of the historical shock is affected by a certain degree of uncertainty, on the basis of this distance we suggest that the two earthquakes likely occurred on separate faults. Thus, considering the location and magnitudes of the 1693 and 2012 events and their relation with the Pollino and Castrovillari faults, one can suppose that during these two earthquakes only small portions of a greater seismogenic system slipped. However, we cannot rule out the possibility that the 1693 earthquake may have been originated on a more minor structure in the region.
A systematic investigation of the 1693 Pollino earthquake allowed us to retrieve a great amount of new data and to widen our knowledge of the event. The main findings of our study can be summarized as follows:
an improvement of the macroseismic database from 7 or 8 localities to 16 with a wider spatial distribution of the intensities;
a more reliable picture of the seismic sequence that affected northern Calabria for about one year, starting in January 1693, and a clear distinction of that seismicity with the temporally overlapping sequence in Sicily;
a downsizing to MCS 7 of the maximum (and epicentral) intensity reached by the Pollino mainshock and a decrease of its macroseismic magnitude from Mw 5.7 to 5.2;
more constraints on the location and size of the mainshock; and
similarities between the mainshocks of the historical 1693 and modern 2010–2013 sequences, that could be possibly have originated on limited, adjacent segments of a greater seismogenic fault system.
In summary a principal outcome of this study is that on the southern side of the Pollino Massif, there is no evidence of earthquakes with magnitudes greater than 5.1–5.3 in the past half‐millennium, substantiating a difference between the historic and paleoseismological seismic behavior in this area.
We want to thank V. Castelli for the translation from Latin of many documents, and B. Brizuela and J. Dinares Turrell for the translation from Spanish and the correspondence with Spanish archives in Valladolid. We also are grateful for the patience and kindness of all archivists, parish priests, and all whom we consulted in search of original material. V. Toscani permitted us to read an original manuscript that was vital for our results. L. Alfonsi, R. Azzaro, and P. Galli read and corrected a first draft of the manuscript and provided important suggestions. Finally, a very detailed revision made by an anonymous reviewer strongly improved the paper. This study has benefited from funding provided by the Italian Presidenza del Consiglio dei Ministri—Dipartimento della Protezione Civile (DPC). This paper does not necessarily represent DPC official opinion and policies.