According to CIVISA, the event was recorded at 2:55 am local time (3:55 am in Lisbon) and had its epicenter around five kilometers southwest of Altares.
"According to the information available so far, the earthquake was felt with maximum intensity III (Modified Mercalli scale) in Quatro Ribeiras (municipality of Praia da Vitória)", said CIVISA, in a statement.
This event is part of "the ongoing seismovolcanic crisis on the island of Terceira since June 2022".
According to the Richter scale, 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 (when greater than 10).
The Modified Mercalli scale measures the degrees of intensity of earthquakes.
With intensity III, considered weak, the shock is felt inside the house and hanging objects swing, perceiving a "vibration similar to that caused by the passage of heavy vehicles", according to the Portuguese Institute of the Sea and Atmosphere (IPMA ).
