Earthquake Engineering Research Institute
Learning From Earthquakes

Summary of the 29th May aftershock

February 4, 2018

After the strong earthquake on May 20th (Emilia Earthquake: The Event), and following the constant seismic activity that has characterized the past few days with several small earthquakes (more than 700), another relevant seismic event was recorded on May 29th.

A strong earthquake of local magnitude Ml 5.8 (Mw 5.65) occurred at 09:00:03 italian time (07:00:03 UTC) in Emilia Romagna (province: Modena) in the seismic district of Pianura Padana emiliana, in the western part of the strip that was activated during the May 20th event (http://www.ingv.it/). The epicenter was identified by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) at 44.851°N, 11.086°E and 10.2 km depth, less than 10 km far from Camposanto (MO), Cavezzo (MO), Medolla (MO), Mirandola (MO), San Felice sul Panaro (MO), San Possidonio (MO), San Prospero (MO). Figure 1 shows the localization of the epicenter (Figure 1), compared to the May 20th one and the peak ground acceleration recorded by some stations of the RAN and RAIS seismic networks is shown.

 

Figure 1 

 

The identified focal mechanism shows a compressive movement on approximately east-west oriented faults and north-south compression, analogous to that observed during the May 20th earthquakes and subsequent days. Therefore, it seems to be the same fault or a parallel fault oriented in the same way as the May 20th one (http://www.ingv.it/).

Several other earthquakes followed the event,  including a significant 5.3 Ml one at 12:55:57 Italian time (10:55:57 UTC), with 44.89°N, 11.01°E and 6.8 km depth and, a few minutes later, a 5.2 Ml one at 13:00:25 Italian time (11:00:25 UTC), with epicenter 44.88°N, 10.95°E and 5.4 km depth.

At present the death toll stands at 17 deaths (among Mirandola, San Felice sul Panaro, Medolla, Concordia and Novi) and 350 injured, with a total of 24 deaths and approximately 16.000 homeless from the combined events.