The alert level for Terceira’s Santa Barbara volcano has been raised to V3 and for the island’s fissure volcanic system to V1 due to seismic activity, according to the Azores Seismovolcano Monitoring Centre.
“Given that since March 2024, seismic activity in the western sector of Terceira Island has clearly exceeded normal levels and was accompanied by some signs of crustal deformation. [nos corpos rochosos]Due to facts indicating the occurrence of a magmatic intrusion at depth, the crisis office has decided to raise the alert level of the Santa Barbara volcano to V3 and the Terceira fissure volcanic system to V1,” says the website of the Center for Information and Seismic Volcanic Observation of the Azores (CIVISA ).
According to information available on the CIVISA website, at volcanic alert levels V0 means “quiescent” and V6 means “continuing eruption”.
Volcano Santa Barbara was at level V2, which means possible reactivation of the system, now moving to the next level (confirmation of system reactivation).
According to the Institute of Volcanology of the University of the Azores (IVAR), the information obtained through the monitoring network managed by CIVISA allows us to verify that the seismovolcanic crisis registered on the island of Terceira since June 24, 2022, “continues, showing clear signs of increasing”.
During this crisis, seismic activity was concentrated “with greater frequency within the perimeter of the Santa Barbara volcano and was essentially characterized by the occurrence of microseisms.”
The most powerful earthquake occurred on January 14, 2024 at 7:19 local time with a magnitude of 4.5 on the Richter scale and an epicenter approximately one kilometer east of Serreta and was felt with a maximum intensity of VI on the scale. Modified Mercalli, in the western sector of the island.
At that time, according to CIVISA, “some cracks were recorded in houses with little resistance to seismic effects, the collapse of loose stone walls, damage to some communication routes and landslides inside the island and on the cliffs.”
On the Richter scale, earthquakes are classified by magnitude into micro (less than 2.0), very small (2.0-2.9), small (3.0-3.9), weak (4.0-4.9), moderate (5.0-5.9), medium (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 above 10).
The Modified Mercalli Scale measures the intensity of earthquakes.
According to the Portuguese Institute of the Sea and Atmosphere (IPMA), at intensity III, considered weak, the shock is felt inside the house and hanging objects swing, feeling “a vibration similar to that caused by the passage of heavy vehicles.”
On the other hand, CIVISA explains that recorded seismicity also covered, although less frequently, the Terceira fissure volcanic system, especially in the area that crosses the Santa Barbara mountain range and extends to the surroundings of the golf club in the east.
The organization also states that activity occurred further south, east of the Santa Barbara volcano’s zone of influence, in the area between Cinco Ribeiras and Angra do Heroísmo, “and out to sea, to the west and south.” islands.”
“The phenomenon that affected the island of Terceira cannot be separated from the increase in seismic-volcanic activity that has occurred in the Azores region and in particular in the Central Group since the beginning of 2022,” he explains.
CIVISA allows for the possibility that events experienced by the population will continue to occur, the scale and intensity of which may exceed those recorded to date, taking into account the “observed pattern of activity”.
Author: Lusa
Source: CM Jornal
I am Michael Melvin, an experienced news writer with a passion for uncovering stories and bringing them to the public. I have been working in the news industry for over five years now, and my work has been published on multiple websites. As an author at 24 News Reporters, I cover world section of current events stories that are both informative and captivating to read.