Two earthquakes with a magnitude of 2.0 and 1.9 on the Richter scale were felt yesterday in Terceira at 16:49 and 16:50 local time (17:49 and 17:50 in Lisbon), following another tremor recorded at dawn on the Azorean island, the authorities said.
According to the Seismic Informationand Surveillance Centre of the Azores (CIVISA), the first event had an epicenter about two kilometers south-southeast of Serreta and the second three kilometers to the east-southeast of the same place, on Terceira island.
“According to the information available so far, the earthquakes were felt with a maximum intensity of III (Modified Mercalli scale) in Doze Ribeiras and Serreta (Angra do Heroísmo municipality),” CIVISA said in a statement.
At 00:37 local time (01:37 in Lisbon) yesterday, an earthquake with a magnitude of 1.8 on the Richter scale and an epicenter about four kilometers east of Serreta had already been recorded.
The earthquake was felt with a maximum intensity of III (Modified Mercalli scale) in Serreta.
The three events are part of “the ongoing seismic-volcanic crisis on Terceira Island 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 “degrees of intensity and their description”.
With an intensity of III, considered weak, the earthquake is felt inside the house and pending objects sway, with a “vibration similar to that caused by the passage of heavy vehicles”, reveals the Portuguese Sea and Atmosphere Institute (IPMA) on its website.
