On April 30, 2013, at 06:25 (local time) occurred in the Eastern Group of the Azores an earthquake of magnitude 5.9ML (see file attached ), with the epicenter located about 40km southeast of the Village (S. Miguel .)
This earthquake was felt in the islands of St. Miguel, Santa Maria and Terceira. The island where the impact was greater was S. Michael, having a maximum intensity of V (Modified Mercalli Scale, 1956 - MM56) in some of the localities in the east.
In the other two islands referred to the maximum intensity observed did not exceed grade III and IV (MM56), respectively.
In S. Miguel was still possible to measure the seismic stations values of peak acceleration of about 27cm/s2 Boilers in Ribeira Grande and 23 cm/s2 at Silverside Macela, consistent with levels of seismic intensity grade IV (MM56).
Following this earthquake occurred several aftershocks of lesser magnitude, having been recorded 71 until 15:00 local. The most significant replica reached magnitude 4.5 ML and was felt with maximum intensity IV (MM56) in the Village.
The earthquake of 06:25 UTC is of tectonic origin, and according to a preliminary analysis, the result of a normal fault in the interaction zone between the Eurasian plate and Nubia, with NW-SE direction (see figure).