An earthquake with a magnitude of 2.8 on the Richter scale was recorded at 1:16 PM local time (2:16 PM in Lisbon) with an epicenter approximately five kilometers northeast of Santa Bárbara on Terceira Island, according to CIVISA.
“This event is part of the ongoing seismo-volcanic crisis on Terceira Island since June 2022,” stated CIVISA.
CIVISA further noted that, based on current information, “the earthquake was felt with a maximum intensity of V (Modified Mercalli Scale) in Santa Bárbara, Cinco Ribeiras, S. Bartolomeu, and Terra Chã (municipality of Angra do Heroísmo), as well as in Biscoitos and Quatro Ribeiras (municipality of Praia da Vitória).”
The agency also reported that the earthquake “was felt with an intensity of IV in Doze Ribeiras, Serreta, Raminho, Altares, S. Mateus, and S. Pedro (municipality of Angra do Heroísmo) and with an intensity of III in Santa Luzia, Posto Santo, Nossa Senhora da Conceição, and S. Bento (municipality of Angra do Heroísmo).”
The Richter scale classifies earthquakes by magnitude as 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), significant (9.0-9.9), and extreme (over 10).
The Modified Mercalli Scale measures “degrees of intensity and their description.”
At an intensity of III, considered weak, the tremor is felt indoors and hanging objects sway, producing a “vibration similar to that caused by passing heavy vehicles,” describes the Portuguese Institute for Sea and Atmosphere on its website.
At intensity IV, considered moderate, “suspended objects swing, the vibration is similar to the passing of heavy vehicles or a heavy ball striking the walls, parked cars rock, windows, doors, and dishes rattle, glasses and dishes clink, and at the upper end of this degree, walls and wooden structures creak,” according to the IPMA.
