Papers by Alberto Comastri
With the publication in 1985 of the Catalogue of Italian earthquakes from the year 1000 to 1980 o... more With the publication in 1985 of the Catalogue of Italian earthquakes from the year 1000 to 1980 of the Progetto Finalizzato Geodinamica, curated by Daniele Postpischl, a particularly fruitful period began for historical Seismology and for seismic hazard analysis. During this period, two independent research groups carried out important projects: the Catalogo dei Forti Terremoti (Catalogue of Strong Earthquakes) in Italy, published in 1995 and 1997 by the Istituto Nazionale di Geofisica (National Institute of Geophysics) and by the SGA Storia Geofisica Ambiente, and the NT Catalogue, published in 1997 by the Gruppo Nazionale per la Difesa dai Terremoti (National Group for Defence from Earthquakes). The existance of two catalogues, different for purposes and strategies adopted, but still much more precise and richer in information with respect to the previous ones, has been received with great favour by the scientific world. However, these two catalogues force users to do choices to w...
This historical seismology study examines and supplements what is cur-rently known from written s... more This historical seismology study examines and supplements what is cur-rently known from written sources and archaeological literature about the earthquakes that took place in the area of L’Aquila (central Italy), struck by a damaging earthquake on 6 April 2009 (Mw 6.3), from the ancient Roman period to the late Middle Ages (first through fifteenth century A.D.). The persistence and magnitude of earthquakes in this area has had a strong bearing on the economy and culture of the communities that resided there, a fact borne out by historical accounts. The goal of this revision is to prompt thinking about earthquakes missing from the hazard estimates as well as on return periods for destructive earthquakes in the area. It presents a critical collation of data previously scattered among historical catalogs and writings. Ten earthquakes are examined for their historical and cultural background with a view to highlighting the existence of written sources and explaining both the quality of ...
Reactive magnetron sputtering was used to deposit tantalum nitride (Ta-N) thin films on Si substr... more Reactive magnetron sputtering was used to deposit tantalum nitride (Ta-N) thin films on Si substrate. The effect of varying the N 2 percentage in the N 2 /Ar gas mixture on the TaN film characteristics was investigated. Mechanical and tribological properties were studied using nanoindentation and pin-on-disc wear testing. Decreasing the N 2 content in the gas mixture was found to change the film structure from face centered cubic (fcc) TaN (from 25% to 10% N 2) to highly textured fcc TaN (at 7% N 2) to a mixture of fcc TaN 1.13 and hexagonal Ta 2 N (at 5% N 2), and finally to hexagonal Ta 2 N (at 3% N 2). A high hardness of about 33 GPa was shown by the films containing the hexagonal Ta 2 N phase (5% and 3% N 2). Decreasing the N 2 content below 7% N 2 was also found to result in microstructural refinement with grain size 5-15 nm. Besides the highest hardness, the film deposited with 3% N 2 content exhibited the highest hardness/modulus ratio (0.13), and elastic recovery (68%), and very low wear rate (3.1 × 10 −6 mm 3 •N −1 •m −1).
A new, largely revised and updated version of the Catalogue of Strong Earthquakes in Italy and in... more A new, largely revised and updated version of the Catalogue of Strong Earthquakes in Italy and in the Mediterranean area, termed CFTI5Med, was released in 2018 by Guidoboni et al. (https://doi.org/10.6092/ingv.it-cfti5). The Catalogue collects the results of over three decades of research in historical seismology in Italy and in the Mediterranean area.What makes CFTI5Med different from all other earthquake catalogues is that its database does not only contain parametric data and macroseismic intensities assigned to individual localities, but also textual descriptions of the territorial impact of each investigated earthquake sequence on both the built and the natural environment. For every investigated earthquake sequence, CFTI5Med supplies also the relevant bibliography in an organised form.Instrumental catalogues generally supply one record per earthquake. In contrast, the earthquake effects described by historical sources often refer to the combined effect of multiple shocks belonging to a sequence. For this reason, CFTI5Med presents the data organised "by earthquake sequence", after aggregating shocks that appear reasonably clustered in both time and space.For each investigated earthquake sequence we provide three different types of parametric information:1) the full parameters of each shock of the sequence;2) the intensity (according to the MCS scale) assigned to individual localities where each shock caused damage, or was felt, or was reported not felt;3) a list of effects on the natural environment associated with a single shock (whenever possible) or with the entire sequence, subdivided into 32 different categories and assigned to individual localities.In addition, we supply the following synthetic summaries (in plain text form):• descriptions of the territorial impact and temporal evolution of the entire earthquake sequence;• descriptions of the effects on the built and natural environment for each individual locality.
I diritti di traduzione, di memorizzazione elettronica, di riproduzione e di adattamento totale o... more I diritti di traduzione, di memorizzazione elettronica, di riproduzione e di adattamento totale o parziale, con qualsiasi mezzo (compresi i microfilm e le copie fotostatiche) sono riservati per 42 <08> seconda metà IV-III secolo a.C. descrizione 46
La risposta sismica all’interno di un’area ridotta, come quella urbana, può avere un carattere ri... more La risposta sismica all’interno di un’area ridotta, come quella urbana, può avere un carattere ricorrente, anche a causa di terremoti diversi? La domanda non è banale e presuppone di confrontare diversi scenari di danni avvenuti in una stessa area urbana, in periodi diversi. Il tentativo di evidenziare su base storica se esiste una risposta sismica tipica dell’Aquila ci ha suggerito di localizzare a scala di edifici i danni subiti per due terremoti, ben documentati nella storia della città. Sono stati scelti gli eventi sismici del novembre 1461 (Me 6.3, la stessa valutata per il terremoto del 6 aprile 2009) e il terremoto del 2 febbraio 1703 (Me 6.7). Questo ultimo grande evento sismico seguì di pochi giorni altri due violenti terremoti, accaduti il 14 e 16 gennaio 1703, che colpirono in particolare l’Umbria meridionale e il Lazio orientale. Gli effetti all’Aquila sono classificati per il terremoto del 1461 di IX grado MCS e per quello del febbraio 1703 di X MCS. Il primo epicentro ...
The Catalogue lists earthquakes that occurred in Italy between 461 B.C. and 1997, and earthquakes... more The Catalogue lists earthquakes that occurred in Italy between 461 B.C. and 1997, and earthquakes that occurred in the general Mediterranean area between the VIII century b.C. and the XV century. This version (CFTI5Med) features: the retrieval and formatting of over 23,000 original bibliographic documents, transcribed or printed, nearly 50% of those utilized in the CFTI5Med. These documents are now available on-line as fully searchable pdf files; a full geological reinterpretation, georeferencing and reprocessing of over 2,300 descriptions of earthquake-induced environmental effects, which are now all available and searchable in a user-friendly web-GIS environment; the elaboration of a number of texts and commentaries that were missing from the CFTI4Med version of the catalogue; a totally re-designed and more efficient web- and web-GIS interface. The new Catalogo dei Forti Terremoti in ltalia includes 1,259 earthquakes that occurred in Italy (98 of which are currently considered false). No commentaries on the main earthquake effects were available in the previous version of the catalogue for 87 of such events as they had not been updated with respect to the information supplied in Guidoboni e Comastri (2005) for the 1000 AD-1500 AD time interval. The commentaries concerning the most significant effects of Italian medieval earthquakes have now been elaborated and are available along with the information on more recent events. For the remainder of the earthquakes first presented with the CFTI4Med - those that occurred in the general Mediterranean area away from the Italian coasts - the new catalogue provides only the felt reports and basic epicentral parameters.
Annals of Geophysics, 2009
Scientific Data, 2019
A key element for assessing seismic hazard and risk is the availability of a comprehensive datase... more A key element for assessing seismic hazard and risk is the availability of a comprehensive dataset on past earthquakes. Here we present the rationale, structure and contents of CFTI5Med (https:// doi.org/10.6092/ingv.it-cfti5), the 2018 version of the Catalogue of Strong Earthquakes in Italy: a large multidisciplinary effort including historians, seismologists and geologists. It was conceived in 1989, following the inception of GIS technology, and first published in 1995 to offer a full account of Italy's strongest earthquakes, of their territorial impact and associated social and economic upheaval. Subsequent versions (1997, 2000, 2007) entailed a fine tuning of research methodologies, included additional research on Italian earthquakes, and were extended to large earthquakes of the Mediterranean area. CFTI5Med comprised an opportunity to streamline the structure of the Catalogue database and propose a renovated user interface. The new front-end (1) grants an easier, intuitive access to the data, including earthquake effects on the environment, and (2) allows all data to be displayed jointly with relevant topographic, geological and seismological overlays published as web services.
Journal of African Earth Sciences, 2019
Abstract On 21 August 1986 almost 1800 people were asphyxiated by a CO 2 cloud violently released... more Abstract On 21 August 1986 almost 1800 people were asphyxiated by a CO 2 cloud violently released by Lake Nyos, Cameroon. Post-1986 monitoring of Lake Nyos revealed that CO 2 steadily accumulates in bottom waters through recharge from soda-rich aquifers. The 1986 lake roll-over event triggered scientific research on volcanic lakes, creating “Nyos biased” interpretations: the search for dissolved CO 2 in other lakes might have led to over-interpretations regarding hazard assessment. In this study, a thorough review of the historical literature on Lago Albano over the past approx. 2800 years shows no clear evidence of Nyos-type bursts, contrary to previous ideas. In 1989 Lago Albano was affected by a large CO 2 pulse, concomitant with a seismic swarm below Colli Albani volcano. Tracing back in historical literature, at least two similar anomalous degassing episodes occurred out of five seismic crises between 1829 and 1927. Partial temperature- and density-driven roll-over of the top-9 m of Lago Albano commonly releases accumulated CO 2 each winter (Chiodini et al., 2012). This degassing dynamics avoids long-term CO 2 accumulation in bottom waters, as is the case at permanently stratified lakes in the tropics, such as Lake Nyos. Here we show that Lago Albano is an “anti-Nyos-type" lake: sudden recharge and regularly periodic release of CO 2 (Lago Albano) vs. steady recharge and sudden release of CO 2 (Lake Nyos). Despite past evidence of hazardous events, (1) the intensive well pumping from the Albano aquifer might lower lake level, and hence decrease the CO 2 saturation pressure threshold, and (2) the absence of cold winters, hence avoiding yearly lake roll-over favoring CO 2 accumulation at bottom layers, are modern factors that rise the need to revise hazard assessment and future monitoring strategies. Despite the fact that CO 2 concentration in bottom waters was far from saturation conditions during the last survey (May 2010; Chiodini et al., 2012), making a limnic eruption highly unlikely, it is necessary to know the saturation state of CO 2 in bottom waters and physical lake stability at any time, in order to be prepared for a next anomalous co-seismic CO 2 degassing event of unknown quantity near Lago Albano.
Israel Journal of Earth Sciences, 2009
... Amos Salamon,a Thomas Rockwell,b Emanuela Guidoboni,c and Alberto Comastric aGeological Surve... more ... Amos Salamon,a Thomas Rockwell,b Emanuela Guidoboni,c and Alberto Comastric aGeological Survey, 30 ... Ambraseys and Jackson (1998) estimated that this was a large, 7.0 &amp;gt; Ms ≥ 7.8, event. ... et al., 1994, 2002; Guido-boni et al., 1994; Dominey-Howes, 2002; Shaw et al ...
Journal of Seismology, 1997
By conducting a historical review of this large seismic event in the Mediterranean, it has been p... more By conducting a historical review of this large seismic event in the Mediterranean, it has been possible to identify both the epicentral area and the area in which its effects were principally felt. Ever since the nineteenth century, the seismological tradition has offered a variety of partial interpretations of the earthquake, depending on whether the main sources used were Arabic,
Journal of Seismology, 2004
Mn beschäftigt sich jetzt viel mit dem Begriff ,,Kon-stitutiOfl", man will ihn so klar fassen, da... more Mn beschäftigt sich jetzt viel mit dem Begriff ,,Kon-stitutiOfl", man will ihn so klar fassen, daß er etwas Bestimmtes besagt. Aber er ist nicht zu fassen, er zeigt immer wieder Lücken. Der Ausdruck Konstitution" ist nur ein Notbehelf, wie wir auch sonst ein Wort in der Wissenschaft gebrauchen, obwohl wir uns bewußt sind, daß es nicht alles, was wir meinen, in sich schließt. Konstitution" ist nicht der letzte feststehende Grund. Man sagt von einem Menschen, daß er eine gute, daß er eine schlechte Konstitution habe. Aber man sagt auch von einem Menschen, daß er eine gute Konstitution habe, wenn er viele schwere Krankheiten überwunden hat, und ebenso, wenn er niemals krank gewesen ist, obwohl er schwer gearbeitet und sich auch
Journal of Geophysical Research, 2005
In the seismological literature the 3 January 1117 earthquake represents an interesting case stud... more In the seismological literature the 3 January 1117 earthquake represents an interesting case study, both for the sheer size of the area in which that event is recorded by the monastic sources of the 12th century, and for the amount of damage mentioned. The 1117 event has been added to the earthquake catalogues of up to five European countries (Italy, France, Belgium, Switzerland, the Iberian peninsula), and it is the largest historical earthquake for northern Italy. We have analyzed the monastic time system in the 12th century and, by means of a comparative analysis of the sources, have correlated the two shocks mentioned (in the night and in the afternoon of 3 January) to territorial effects, seeking to make the overall picture reported for Europe more consistent. The connection between the linguistic indications and the localization of the effects has allowed us to shed light, with a reasonable degree of approximation, upon two previously little known earthquakes, probably generated by a sequence of events. A first earthquake in lower Germany (I 0 (epicentral intensity) VII-VIII MCS (Mercalli, Cancani, Sieberg), M 6.4) preceded the far more violent one in northern Italy (Verona area) by about 12-13 hours. The second event is the one reported in the literature. We have put forward new parameters for this Veronese earthquake (I 0 IX MCS, M 7.0). A third earthquake is independently recorded in the northwestern area of Tuscany (Imax VII-VIII MCS), but for the latter event the epicenter and magnitude cannot be evaluated.
Geophysical Research Letters, 2014
Campi Flegrei (Italy) caldera has experienced episodes of ground deformation throughout its geolo... more Campi Flegrei (Italy) caldera has experienced episodes of ground deformation throughout its geological history, alternating between uplift and subsidence phases. Although uplift periods are typically more alarming, here we focus on subsidence, looking for its driving mechanisms and its role in the caldera evolution. Historical and archaeological records constrain ground deformation over the last two millennia. Here we revise such records and combine them with published radiometric dating and with the simulation of sea level change. The resulting analysis highlights for the first time a rapid subsidence during the fifth century. We show that rate and magnitude of this subsidence are consistent with the compaction of porous material caused by a pressure drop of~1 MPa within the hydrothermal system. We interpret this event as the decompression of the hydrothermal system following an unrecognized episode of unrest, during Roman times. These findings redefine the pattern of ground deformation and bear important implications for volcanic hazard assessment.
Bulletin of the Seismological Society of America, 2007
Seismic sea waves in the eastern Mediterranean have been reported since written history first eme... more Seismic sea waves in the eastern Mediterranean have been reported since written history first emerged several thousand years ago. We collected and investigated these ancient and modern reports to understand and model the typical tsunamigenic sources, with the ultimate purpose of characterizing tsunami hazard along the Levant coasts. Surprisingly, only 35% of the tsunami reports could be traced back to primary sources, with the balance remaining questionable. The tsunamis varied in size, from barely noticeable to greatly damaging, and their effects ranged from local to regional. Overall, we list 21 reliably reported tsunamis that occurred since the mid second century B.C. along the Levant coast, along with 57 significant historical earthquakes that originated from the "local" continental Dead Sea Transform (DST) system. An in-depth evaluation shows that 10 tsunamis are clearly associated with on-land DST earthquakes, and therefore, as formerly suggested, they probably originated from offshore, seismogenically induced slumps. Eight tsunamis arrived from the "remote" Hellenic and Cypriot Arcs, one from Italy, and two are left with as yet unrecognized sources. A major conclusion from this work is that onshore earthquakes commonly produce tsunamis along the Levant coastline, and that analogous situations are present elsewhere in the Mediterranean, as well as along the California coast and in another regions with active faults near the coast. We modeled three typical scenarios, and in light of the Sumatra experience, we examined the more likely severe magnitudes. This of course leads us toward the upper range of expected run-ups. The models show that sooner than five minutes after a strong earthquake produces an offshore slump, which occurs after close to a third of the large DST earthquakes, a 4-to 6-m run-up may flood part of the Syrian, Lebanese, and Israeli coasts. Tsunamis from remote earthquakes, however, arrive later and produce only 1-to 3-m run-ups, but are more regional in extent.
Bulletin of the Seismological Society of America, 2012
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Papers by Alberto Comastri