The Philippine Institute of Volcanology and Seismology (Phivolcs) warned Sunday of increased real-time seismic energy release (RSAM) in Mayon Volcano, which is currently under Alert Level 3, amid the likelihood of its ongoing unrest lasting for months.
Latest advisory from the state seismic agency said at least six of their 16 stations around the Mayon Volcano recorded heightened RSAM.
“This increase was induced by background tremor while no other volcanic earthquakes have been detected, which may be due to prevailing fully open vent conditions as the volcano effusively erupts,” the Phivolcs said on January 11.
Phivolcs noted that while RSAM has begun decreasing, as of its 12:45 p.m. advisory, “this episode could forewarn of new intrusions into the Mayon edifice that could lead to further eruptive activity.”
Earlier, Phivolcs director Dr. Teresito Bacolcol said in a radio interview that the ongoing unrest may last for months. “If we follow the 2023 template, this would probably take six months… In 2023, the activity at Mayon Volcano subsided six months later,” he told Super Radyo DZBB.
Based on latest assessments, the volcano’s recent unrest was described as a quiet eruption, similar to its effusive eruption in June 2023.
“What happened in 2023, there was lava flow after several days. In fact, before it ended, the activity just reached almost more than a three-kilometer lava flow. As of now, we haven’t seen this yet,” the Phivolcs chief explained.
Bacolcol pointed out that they have not yet observed intensified parameters from the Mayon Volcano, which would require Phivolcs to raise its alert level from 3 to 4. He said there is still no lava flow based on their monitoring, noting that the lava remains in the volcano’s crater.
The red lava-like releases sighted in the past days were not lava flows, he explained, reiterating that these were just pyroclastic density currents (PDCs)—locally referred to as ‘uson’—and rockfalls, which appear as white in color during daytime but turns red at night.
As of 5:00 a.m. on January 11, Phivolcs recorded a total of 256 rockfall events and 41 PDCs in Mayon. It has emitted a total of 777 tons of sulfur dioxide per day since January 10, 2026 and crater glow also persists.
Phivolcs advised residents within the six-to-eight-kilometer permanent danger zone (PDZ) to immediately leave amid risks of volcanic hazards worsened by possible torrential rains. Those beyond the PDZ but are near rivers flowing from the volcano’s slope must also evacuate due to possible lahar flow.
“Increased vigilance against lahars and sediment-laden streamflows along channels draining the edifice is also advised in the event that intense rains occur over the summit area. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit,” it added.
Phivolcs also continues to monitor ongoing activities in other volcanoes including Taal in Batangas, which is under Alert Level 1; Bulusan in Sorsogon, also under Alert Level 1; and Kanlaon in the Negros Island Region, which is under Alert Level 2.
Editor’s Note: This story has been updated. Originally posted with the headline “Mayon Volcano unrest may last for months—Phivolcs.”
