An earthquake struck at 01:59 (02:59 in Lisbon) according to the Azores Seismic Network stations, with its epicenter located six kilometers from Altares (Terceira).
Currently available information indicates that the quake was felt at a maximum intensity of III (Modified Mercalli Intensity Scale) in Cinco Ribeiras (Angra do Heroísmo municipality).
The Azores’ Center for Seismic and Volcanic Surveillance and Information (CIVISA) reported that the tremor “is part of the ongoing seismic-volcanic crisis on Terceira Island since June 2022.”
The Richter scale categorizes earthquakes by magnitude: micro (less than 2.0), very minor (2.0-2.9), minor (3.0-3.9), light (4.0-4.9), moderate (5.0-5.9), strong (6.0-6.9), major (7.0-7.9), great (8.0-8.9), exceptional (9.0-9.9), and extreme (above 10).
The Modified Mercalli Intensity scale measures “degrees of intensity and their respective descriptions.”
An intensity of III is considered weak, noticeable indoors, causing pendulum objects to sway, and is described as a “vibration similar to that caused by the passage of heavy vehicles.”
