The Emilia 2012 sequence: a macroseismic survey

Andrea Tertulliani Andrea Tertulliani,Manuela Sbarra Manuela Sbarra,Antonio Rossi Antonio Rossi,Laura Graziani Laura Graziani,Filippo Bernardini Filippo Bernardini,Beatriz Brizuela Beatriz Brizuela,Alessandra Maramai Alessandra Maramai,Sergio Del Mese Sergio Del Mese,Corrado Castellano Corrado Castellano,Emanuela Ercolani Emanuela Ercolani,Luca Arcoraci Luca Arcoraci,Michele Berardi Michele Berardi,Maurizio Vecchi Maurizio Vecchi

doi:10.4401/ag-6140

Abstract

<p>On May 20, 2012, at 4:03 local time (2:03 UTC), a large part of the Po Valley between the cities of Ferrara, Modena and Mantova was struck by a damaging earthquake (Ml 5.9). The epicenter was located by the Istituto Nazionale di Geo-fisica e Vulcanologia (INGV) seismic network [ISIDe 2010] at 44.889 ˚N and 11.228 ˚E, approximately 30 km west of Ferrara (Figure 1). The event was preceded by a foreshock that occurred at 01:13 local time, with a magnitude of Ml 4. The mainshock started an intense seismic sequence that lasted for weeks, counting more than 2,000 events, six of which had Ml &gt;5. The strongest earthquakes of this sequence occurred on May 29, 2012, with Ml 5.8 and Ml 5.3, recorded at 9:00 and 12:55 local time, respectively. The epicenters of the May 29, 2012, events were located at the westernmost part of the rupture zone of the May 20, 2012, earthquake (Figure 2). The May 20 and 29, 2012, earthquakes were felt through the whole of northern and central Italy, and as far as Switzerland, Slovenia, Croatia, Austria, south-eastern France and southern Germany. Historical information reveals that the seismic activity in the Po Valley is moderate […]</p>

Highlights

On May 20, 2012, at 4:03 local time (2:03 UTC), a large part of the Po Valley between the cities of Ferrara, Modena and Mantova was struck by a damaging earthquake (ML 5.9)
The epicenter was located by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) seismic network [ISIDe 2010] at 44.889 ̊N and 11.228 ̊E, approximately 30 km west of Ferrara (Figure 1)
The event was preceded by a foreshock that occurred at 01:13 local time, with a magnitude of ML 4

Summary

Introduction

On May 20, 2012, at 4:03 local time (2:03 UTC), a large part of the Po Valley between the cities of Ferrara, Modena and Mantova was struck by a damaging earthquake (ML 5.9). The highest intensity values (I >7 EMS98) were assigned to six localities (Table 1), where a few collapses were observed, both in buildings of reinforced concrete (vulnerability class C) and masonry (vulnerability classes A and B) In these localities, many buildings suffered heavy damage, such as large and extensive cracks, failure of walls and roofs, and extensive falling of chimneys and roof tiles. Intensity values as high as 7 were assigned to six localities, where a large number of masonry buildings of vulnerability classes A and B suffered moderate damage, as grades 2 and 3, such as large cracks in walls and the falling of chimneys and roof-tiles. In 32 localities, the damage observed was either slight or negligible, which resulted in intensity values of 5 or 5-6 In these cases, the damage reported was usually falling chimneys and small pieces of plaster, but it was not widespread through the whole building stock. Cavezzo Concordia sulla Secchia Mirandola Moglia Novi di Modena Rovereto sulla Secchia Canaletto Finale Emilia Fossoli Ponte San Pellegrino Reggiolo San Felice sul Panaro Alberone Camposanto Crevalcore Mirabello San Carlo San Giacomo delle Segnate Bondanello Bondeno Bondeno Carpi Casumaro Cento Massa Finalese Medolla Motta Poggio Renatico Poggio Rusco Ponte Rodoni Quistello Rivara San Martino Spino San Possidonio San Prospero Sant'Agostino Scortichino Villarotta Buonacompra Camurana Caselle Forcello Galeazza Malcantone di Medolla

Bondeno Luzzara Cento Medolla Crevalcore San Possidonio Crevalcore Medolla

Macroseismic parameters

Conclusions