MANILA, Philippines — The Taal Volcano generated 252 earthquakes in a 24-hour monitoring as it remains under alert level 2, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Monday.
Based on the volcano bulletin issued by Phivolcs at 8 a.m., the earthquakes included 17 episodes of volcanic tremor with durations of one to four minutes and five “hybrid events.”
Phivolcs said activity at the main crater consisted of “moderate emission of steam-laden plumes from fumarolic vents” that rose 10 meters high.
“An upwelling of high temperature volcanic gases at the lake’s surface was observed last night from 6:30 PM to 8:45 PM. Sulfur dioxide (SO2) emission that averaged 518 tonnes/day was measured yesterday, 14 March 2021,” it added.
Temperature highs of 71.8 degrees Celsius and pH of 1.59 were last measured from the main crater lake on March 4 and February 12, respectively, according to the agency.
It noted that ground deformation parameters from electronic tilt and data analysis from the Global Positioning System and Interferometric Synthetic Aperture Radar indicated a “very slow and steady inflation and expansion of the Taal region since after the phreatic eruption in January last year.
“These parameters may indicate increased magmatic activity at shallow depths beneath the edifice,” said Phivolcs.
Phivolcs explained that under alert level 2, which means increased unrest, 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 (TVI).
Phivolcs strongly recommends that entry into the TVI and Taal’s Permanent Danger Zone, especially the vicinity of the main crater and the Daang Kastila fissure, must remain strictly prohibited.
It also advised local government units to continuously assess and strengthen the preparedness of previously evacuated barangays around the Taal Lake in case of renewed unrest.