In a statement, IPMA said that the earthquake had its epicenter around four kilometers south of Altares, on the island of Terceira, and was recorded at 00:45 (01:45 in Lisbon) at the stations of the Seismic Network of the Azores Archipelago

This shock was felt with maximum intensity III/IV (modified Mercalli scale) in the parish of Biscoitos.

It was also felt with less intensity in the parish of Terra Chã.

Earthquakes are classified according to their magnitude as micro (less than 2.0), very small (2.0-2.9), small (3.0-3.9), slight (4.0-4.9 ), moderate (5.0-5.9), strong (6.0-6.9), large (7.0-7.9), important (8.0-8.9), exceptional (9. 0-9.9) and extreme (greater than 10).

According to the IPMA definition, at level III of the modified Mercalli scale, earthquakes can be felt inside the house, hanging objects swing, the vibration is similar to that caused by the passage of heavy vehicles and it is possible to estimate the duration but not can be recognized as an earthquake.