In May–June 2012, the Po Valley (Northern Italy) was struck by an earthquake sequence whose strongest event occurred on 20 May (Mw 5.9). The intensity values (Imax 7–8 EMS98) assessed through macroseismic field surveys seemed inappropriate to describe the whole range of effects observed, especially those to monumental heritage, which suffered very heavy damage and destruction. The observed intensities in fact were significantly lower than those we could have expected after a Mw 5.9 event for Italy. As magnitude-intensity regressions are mainly based on historical earthquake data, we handle this issue going back in time and debating the following hypotheses: (a) the 2012 Emilia earthquake sequence shows lower intensity values than expected because the affected urban context is more heterogeneous and much less vulnerable than that in the past; (b) some historical earthquakes, especially those that occurred centuries ago and are provided with little information, could show a tendency to be overestimated in intensity, and consequently in magnitude. In order to give consistency to such hypotheses, we have introduced, as a test, a dual historical reading of the 2012 Emilia earthquake sequence as if it had occurred in the past: the first reading refers to a period prior to the introduction of concrete in buildings assessing the intensity on traditional masonry buildings only. A further historical reading, assessed by using information on monumental buildings only, was performed, and it can be roughly referred to the XVI–XVII centuries. In both cases, intensity values tend to grow significantly. The results could have a relevant impact when considered for seismic hazard assessments if confirmed on a large scale.

This paper describes the damage survey in the city of L’Aquila after the 6 April 2009 earthquake. The earthquake, whose magnitude and intensity reached Mw = 6.3 and Imax = 9–10 MCS, struck the Abruzzi region of Central Italy producing severe damage in L’Aquila and in many villages along the Middle Aterno River valley. After the event, a building-to-building survey was performed in L’Aquila downtown aiming to collect data in order to perform a strict evaluation of the damage. The survey was carried out under the European Macroseismic Scale (EMS98) to evaluate the local macroseismic intensity. This damage survey represents the most complex application of the EMS98 in Italy since it became effective. More than 1,700 buildings (99% of the building stock) were taken into account during the survey at L’Aquila downtown, highlighting the difficult application of the macroseismic scale in a large urban context. The EMS98 revealed itself to be the best tool to perform such kind of analysis in urban settings. The complete survey displayed evidence of peculiar features in the damage distribution. Results revealed that the highest rate of collapses occurred within a delimited area of the historical centre and along the SW border of the fluvial terrace on which the city is settled. Intensity assessed for L’Aquila downtown was 8–9 EMS.

This paper presents an overview of the activities performed during the macroseismic field survey of the earthquake that occurred in the Parma and Reggio Emilia region on December 23, 2008. The mainshock (Ml=5.2), was located south of the city of Parma and was resolutely felt through Northern Italy. The report here presented shows the procedures carried out by QUEST (Quick Earthquake Survey Team), concerning the survey. QUEST has been engaged in gathering the damage information and in assessing the macroseismic intensity, in particular about the epicentral area. A copious photo collection shows details of the observed damage nature and allows to better illustrate the intensity assessment.

During World War II four moderately damaging earthquakes occurred in a portion of the Apennines crossed by the regional borders of Latium, Umbria and the Marches. The current parametric earthquake catalogues fail almost completely to record them. The earthquake of December 19, 1941 is well attested by historical sources but no Italian parametric earthquake catalogues ever recorded it. Those of January 16 and 29, 1943 were listed in the earliest Italian catalogues [Carrozzo et al., 1973; Postpischl, 1985] but they disappeared from the "NT generation" catalogues [Camassi and Stucchi, 1998; Working Group CPTI, 1999 and 2004], compiled with declustering procedures. The earthquake of March 25, 1943 is the only one to be recorded by current catalogues, but its parameters were assessed from a very poor macroseismic data base.Original information on these "lost" earthquakes was collected by an ongoing study of the October 3, 1943 earthquake (Southern Marches) and new epicentral parameters have been assessed for them. This experience is a reminder that earthquake catalogues can be incomplete not only in far off centuries but, sometimes, in recent years as well.

E presentata un'analisi del campo macrosismico del terremoto irpino del 1980che per magnitudo ed estensione dell'area interessata risulta il maggiore eventosismico verificatosi in Italia negli ultimi cinquanta anni.L'insieme dei dati rilevati mediante indagini dirette e/o a mezzo schedamacrosismica consente la definizione dell'intensità sismica in 1286 centri abitati di13 regioni.Il campo regionale confrontato con i modelli di Blake (Y= 5.0), risultacompatibile con i seguenti parametri focaliI0 = X" MSK ; = 9.99 ± 0.5 MSK ; h,, = 15 Km.L'anisotropia del campo regionale è analizzata mediante la determinazionedell'attenuazione azimutale dell'intensità (a. z) i cui valori estremi risultano2 . 0 - IO"3 e 3.9 • IO"3, rispettivamente lungo le direzioni NNW e SW.e 3.9 • IO"3, rispettivamente lungo le direzioni NNW e SW.L'area mesosismica risulta caratterizzata principalmente da domini strutturali,rilevati con il metodo shadow, con direzione appenninica (NW-SE), antiappenninicae meridiana (N-S).

This note presents a study meant to set out a national catalogue(C.S.N.) of seismic events the epicentres of which are to be found inItalian territory (or nearby). The catalogue, that will start from theyear 1450 B.C., could be used for various purpose employing moderntechnologies.The complete C.S.N, is made of three main parts, each of which canalso have a separate life:1) An Analytical Catalogue which comprises the greater part ofdata and is the most complete;2) A Macroseismic Atlas that shows the macroseismic aspect ofthe most relevant events;3) A Macroseismic Catalogue that translates in numeric terms theAtlas.To these is added a comprehensive Bibliography subdivided into 24chapters each of which covers one of the 24 time periods into which thecatalogue has been subdivided.The Analytical Catalogue besides giving the main parameters for eachearthquake (date, epicentre, hypocentral depth, MCS scale intensity, raagnitudo,each with its own reliability index) gives indications also on thefollowing sideline data:1) epicentral location (meaning by this the geographic region andthe eventual indication that the epicentre is to be found on a borderlinetouching more geographic regions, or in the sea, or on the coast, or othermisein the external band (see text);2) with a reference to the Atlas, the event is shown as having beendealt with also mocroseismic data and it will con be found, as such, inthe Atlas and in the Macroseismic Catalogue;3) indications on the typology of the earthquake: i.e. whether it is an« isolated » earthquake, or a « seismic period » (and if so with the indicationof the foreshock, main or aftershocks) or of a swarm;4) the possibility of indicating up to 7 sets of information suitablychose among 40 additional notes regarding instrumental, geophysical,physical or sensorial information besides the possibility of notifyingthat the event had undergone specific studies or whether it is even to beconsidered either noth sure or else legendary;5) the possibility of indicating up to four bibliographical items, is tobe considered as capital.The Macroseismic Atlas gives the isoseists of the more supported bydocumentary evidences earthquake, with the calculation of the relativeareas, of the rays of the equivalent circles and of the rays of prevalentmaximal and minimal propagation; these latter with the value of theazimuth measured from the geographical North passing through themacroseismic epicentre.The Macroseismic Catalogue reports numerically the macroseismic dataof the event: analytical and macroseismic epicentre; analytical and macroseismichypocentral depth, numerical values, in km., of the the threeserie of indicated rays, up to isoseist of the 4th degree (MCS).A fac-simile of working form is given.