Terceira Island volcano “possible reactivation”
The Azores Seismovolcanic Surveillance and Information Center says there is no reason to be alarmed by the activity of the Terceira Island volcano.
The Azores Seismovolcanic Information and Surveillance Center (CIVISA) has placed the Santa Bárbara volcano, in Terceira, on scientific alert V2 (possible reactivation of the system), due to levels of microseismic activity, but “no reason for alarm”.
In statements made to Lusa today, the president of CIVISA, Rui Marques, explained that “one of the parameters monitored – seismicity – is clearly above normal values for the volcanic system”, although there is no “reactivation” of it.
There are seven levels of volcanic alert, where V0 stands for “resting state” and V6 “eruption in progress”, according to the CIVISA website.
According to Rui Marques, the decision to place the Santa Bárbara volcano on scientific alert level V2 follows “an increase in seismic activity that began on June 24 and has persisted”.
Since then, “two sense earthquakes” have been recorded, he told Lusa.
“On July 30, there was a major earthquake of 2.5 on the Richter scale, the second earthquake felt,” he added.
The president of CIVISA said that “an average of 17 earthquakes per day are being recorded in the Santa Bárbara volcano, in the last five days”.
“There is a daily increase in the frequency of earthquakes. However, there is no reason for alarm at this time. People must maintain their daily routine”, stressed Rui Marques.
The official stressed that CIVISA “continues to monitor active volcanic systems and, if there is any change, it is immediately communicated to the Regional Civil Protection Service”.
Rui Marques also mentioned that, “recurrently”, the Santa Bárbara volcano “has some increases in seismic activity”, the last of which “occurred between March and December 2020, with more than 500 earthquakes recorded”.
The Azores have “18 active volcanic systems on land,” he added.
Also according to Rui Marques, CIVISA motorizes “50 seismogenic zones”, which “have the capacity to generate seismicity”, but which present “some characteristics different from each other”.
The island of São Jorge currently has an active volcanic alert level V3 (active system with no imminent eruption), following the seismovolcanic crisis recorded since March 19.
The earthquake of greater magnitude (3.8 on the Richter scale) of this crisis occurred on March 29, at 21:56.
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).