During its regular September meeting, the Crise Office of IVAR announced an increase in the alert level from V1 to V2 for the western fissure volcanic system on Terceira Island, prompted by changes in crustal deformation.
The V1 alert from IVAR indicates weak activity slightly above reference levels, caused by tectonic, hydrothermal, and/or magmatic origins.
The V2 alert describes a volcanic system in an “instability phase” with moderate activity significantly surpassing reference levels, stemming from tectonic, hydrothermal, and/or magmatic sources.
IVAR also decided to maintain the V2 alert status for the Santa Bárbara volcano on Terceira Island.
IVAR noted that seismic activity on Terceira Island, though of low magnitude, continued to exceed reference levels, especially at the Santa Bárbara volcano and the western fissure volcanic system.
Seismicity was also recorded between Cinco Ribeiras and Angra do Heroísmo, with the strongest event reaching a magnitude of 3.1 on the Richter scale, felt with a maximum intensity of V on the Modified Mercalli scale, in the western sector of Terceira Island.
September witnessed “the greatest seismic activity of 2025,” with IVAR reporting crustal deformation in the Santa Bárbara volcano area. This deformation began extending to the fissure volcanic system in 2025.
“No gas anomalies have been detected that could be linked to the current seismovolcanic crisis,” IVAR stated.
IVAR has maintained the V1 alert for seismic activity on São Jorge Island, particularly in the Rosais area, which remains slightly above reference levels.
