The Philippine Institute of Volcanology and Seismology (Phivolcs) has detected 42 volcanic earthquakes in the 24-hour monitoring of Taal Volcano from 8 a.m., March 15 to 8 a.m., March 16.
Based on Phivolcs’ volcano bulletin, the earthquakes include 34 episodes of volcanic tremors, which lasted between one minute and eight minutes, and one hybrid event.
Phivolcs also observed “weak” emission of steam-laden plumes rising 5 meters.
Moreover, it measured a significant sulfur dioxide emission that averaged 1,216 tonnes/day last March 15, while temperature highs of 71.8 degrees Celsius and pH of 1.59 were measured from the main crater last March 4 and Feb. 11, respectively.
Ground deformation parameters also indicated a “very slow and steady inflation and expansion of the Taal region since after the January 2020 eruption.”
“These parameters may indicate increased magmatic activity at shallow depths beneath the edifice,” Phivolcs said.
Considering these observations, Phivolcs said Taal Volcano remains under alert level 2 due to “increased unrest.” Its alert level was raised from 1 to 2 on March 9, 2021.
The possibility of sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within the Taal Volcano island, it warned.
Phivolcs asked to public to prevent from entering the volcano island, which is a permanent danger zone, especially the vicinities of the main crater and Daang Kastila fissure.
Local government units were advised to continuously assess and strengthen the preparedness of previously evacuated barangays around Taal Lake in case of renewed unrest.
Civil aviation authorities were also asked to advise pilots to avoid flying close to the volcano as airborne ash and ballistic fragments from sudden explosions and wind-remobilized ash may pose hazards to aircraft.