Mayon Volcano had one rockfall event and 10 volcanic earthquakes during its 24-hour observation period – from 8:00 a.m., Tuesday (March 2) to 8:00 a.m., Wednesday (March 3).
In its volcano bulletin issued on Wednesday, the Philippine Institute of Volcanology and Seismology (Phivolcs) recorded 1.1-magnitude to 3.1-magnitude volcanic earthquakes, with the strongest recorded at 7:41 a.m. on Tuesday.
The strongest quake was felt at Intensity I in the center of the municipality of Sto. Domingo in Albay province.
Phivolcs also observed that activity at Mayon Volcano’s crater consisted of moderate emission of white steam-laden plumes that crept downslope before drifting west and west-southwest.
“Faint crater glow could also be observed during night time,” it said.
Phivolcs last measured the sulfur dioxide (SO2) emission at an average of 222 tonnes/day on February 25, 2021.
“Ground deformation data from continuous GPS (global positioning system) monitoring indicate that the edifice is still inflated relative to July 2019 despite a period of general deflation since July-August 2020, and has been undergoing short-term inflation since November 2020. Deflation of the edifice with short-term inflation of the northwestern slopes since December 2020 has also been recorded by electronic tilt monitoring,” it said.
With these observations, Mayon Volcano remains under Alert Level 1, which means that it is at an “abnormal condition.”
“Although this means that presently no magmatic eruption is imminent, it is strongly advised that the public refrain from entering the six-kilometer radius permanent danger zone (PDZ) due to the perennial life-threatening dangers of rockfalls, landslides/avalanches at the middle to upper slope, sudden ash puffs and steam-driven or phreatic eruptions from the summit,” Phivolcs said.
“Active stream/river channels and those identified as perennially lahar-prone areas on all sectors of the volcano should also be avoided especially during extreme weather conditions when there is heavy and prolonged rainfall,” it added.
Moreover, based on Phivolcs monitoring in the past 24 hours, Taal Volcano had one volcanic earthquake and five volcanic tremor episodes with durations ranging from one minute to three minutes.
Temperature highs of 74.6 degrees Celsius and pH of 1.59 were last measured from the main crater lake, respectively, on Feb. 18 and Feb. 12, 2021, Phivolcs added.
“Ground deformation parameters from continuous electronic tilt on volcano island record a slight deflation around the main crater since October 2020, but overall, very slow and steady inflation of the Taal region has been recorded by continuous GPS data after the eruption,” it noted.
Taal Volcano also remains under Alert Level 1 due to possible sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas that can occur and threaten areas within the Taal Volcano island. Phivolcs strongly discourages entry into the Taal volcano island, which is a permanent danger zone, especially the vicinities of the main crater and the Daang Kastila fissure.
The local government units were also advised to continuously assess previously evacuated barangays around Taal Lake for damages and road accessibilities and to strengthen preparedness, contingency, and communication measures in case of renewed unrest. The public was also asked to continue to observe precautions due to ground displacement across fissures, possible ashfall, and minor earthquakes.