The Emilia 2012 sequence: a macroseismic survey

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 >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 […]

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TERTULLIANI ET AL.
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Event Instrumental parameters Macroseismic parameters
Coordinates
(°N; °E)
ML Coordinates
(°N; °E)
MEW
May 20, 2012 44.889; 11.228 5.9 44.828; 11.241 5.1
May 29, 2012 44.851; 11.086 5.8 - -
Cumulated - - 44.866; 11.017 5.3
Table 2. Instrumental parameters [ISIDe 2010] of the May 20 and 29, 2012, earthquakes, and the macroseismic parameters based on the May 20, 2012,
intensities and the cumulative intensities computed by Boxer 4.0 [Gasperini et al. 2010].
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