An earthquake was registered by CIVISA at 21:54 on Thursday (22:54 in Lisbon) with epicenters approximately three and four kilometers from Santa Bárbara.
The Portuguese Institute for Sea and Atmosphere (IPMA) reported a single earthquake of magnitude 3.8, with an epicenter near Doze Ribeiras, recorded by the Azores Archipelago Seismic Network.
The tremors were felt across the island of Terceira and São Jorge, reaching a maximum intensity of V on the Modified Mercalli scale in the western part of Terceira, CIVISA reported.
The Modified Mercalli scale measures levels of intensity and their respective descriptions.
At intensity V, considered strong, earthquakes are felt outside, people are awakened, liquids oscillate and some overflow, small unstable objects are displaced or knocked over, doors shake, close or open, while blinds and pictures move, and clock pendulums stop or alter their oscillation, according to the IPMA’s website.
On the Richter scale, the two earthquakes in the Azores are classified as small (3.0-3.9).
These events are part of the ongoing seismic-volcanic crisis on Terceira Island since June 2022, CIVISA confirmed.
Earlier, João Luís Gaspar, coordinator of the Crisis Office of the Institute of Volcanology at the University of the Azores (IVAR), announced increased monitoring of the Santa Bárbara volcano, whose volcanic alert level has risen to V3.
“We are currently conducting further fieldwork and next week we will undertake some missions, which we are preparing, to collect gases and waters around the Santa Bárbara volcano,” said geologist João Luís Gaspar in a statement to Lusa.
The alert level for the Santa Bárbara volcano on Terceira Island in the Azores has risen to V3 (volcanic system reactivation), a status it held in the summer of 2024.
Since June 2022, seismic activity at the Santa Bárbara volcano has remained “above normal reference values,” with the most energetic event occurring on January 14, 2024, with a magnitude of 4.5 on the Richter scale.
The volcanic alert level was at V3 from June to December 2024, but since then had remained at V2 (volcanic system instability).
According to João Luís Gaspar, the alert level was raised due to an increase in seismic activity during September and October.
