2012-05-21
Earthquake in Northern Italy – a summary
On Sunday, 20 May 2012, at 04:04 local time an earthquake of magnitude 6 (INGV: M 5.9, USGS: M 6.0, EMSC: M 6.1) occurred in the Emilia Romagna region between the towns of Modena, Ferrara and Bologna. This earthquake was preceded by a magnitude 4.1 foreshock at the same location at 01:45.
The mainshock was followed by numerous aftershocks, the strongest so far with a magnitude 5.1 on Sunday afternoon at 15:28. The main event as well as some aftershocks led to partly severe damage in the vicinity of the epicenter. The shaking from the earthquake could be felt in large parts of Switzerland. It must be expected that within the next days and weeks aftershocks will continue, including strong ones.
The spatial distribution of the nearly 200 aftershocks registered until midday of 21 May in an east-west oriented zone of approx. 40 km length that reaches until Ferrara in the east is likely the expression of the rupture area activated by the mainshock.
The last larger earthquake in the region occurred in 1987 approx. 20 km south of the main event of 20 May and had a magnitude of 5.4. The earthquakes in this region of the Po-plain can be attributed to compression between the Alps and Appenines, which is related to the collision of the African and European plates.
Further information can be found on the INGV websites (IT) and at the USGS (EN).
