Despite the continued presence of new dark lava spines at the summit of Mayon Volcano, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Monday, Dec. 15, that Alert Level 1 (low-level activity) remains in effect, as monitoring data showed no escalation in seismic, gas, or surface activity.

Phivolcs Director Dr. Teresito Bacolcol said the agency has maintained close surveillance of Mayon since releasing close-up photographs on Dec. 10 that showed newly formed lava spines or solidified magma extrusions at the summit.

“Matapos po nating ipakita noong Dec. 10, ang close-up photos ng Mayon summit na may bagong dark lava spines, patuloy naming mino-monitor ang summit activity (After we showed on Dec. 10 the close-up photos of the Mayon summit with new dark lava spines, we continue to monitor the summit activity),” he said in an interview with state-controlled PTV-4.

Bacolcol said results of the 24-hour monitoring as of midnight of Dec. 15 indicate stable conditions.

“Batay sa 24 hour monitoring as of Dec. 15 2025, midnight kanina, walang natalang volcanic earthquake pero may anim tayo na rockfall events and may weak crater glow na makikita lamang sa telescope (Based on the 24-hour monitoring as of Dec. 15, 2025, midnight earlier, no volcanic earthquakes were recorded, but we logged six rockfall events and a weak crater glow that can only be seen through a telescope),” he said.

According to Phivolcs, all monitored parameters remain within the threshold for Alert Level 1.

“Sa ngayon, pasok pa rin naman itong parameters natin sa Alert Level 1 o low-level activity (At present, our parameters are still within Alert Level 1 or low-level activity),” he said.

Bacolcol said seismic activity has remained low, even after the appearance of the lava spines.

“Katulad nung seismic activity natin, mababa pa rin ang volcanic earthquakes natin. Again, for the last 24 hours wala tayo ni isang volcanic earthquake (Similar to our seismic activity, volcanic earthquakes remain low. Again, for the last 24 hours, we did not record a single volcanic earthquake).”

He added that gas emissions have also remained subdued.

“And ‘yung gas emission activity naman natin ay mababa rin (And our gas emission activity is also low),” said Bacolcol.

Asked whether the volcano could erupt in the coming days, Bacolcol said current data do not support such a scenario, though monitoring remains continuous.

“So, kung sasabihin natin kung puputok ba ‘yung bulkan in the next few days ay hindi pa po dahil nasa Alert Level 1 pa rin po tayo pero, again, we are closely monitoring the activities of Mayon Volcano (So, if we are asked whether the volcano will erupt in the next few days, not yet, because we are still at Alert Level 1, but again, we are closely monitoring the activities of Mayon Volcano),” he said.

Phivolcs said Alert Level 1 will only be raised if there is a clear and sustained escalation in volcanic activity.

“Sa ngayon, we maintain Alert Level 1 — minimal level of activity of Mayon Volcano — itataas laman natin kung may clear at sustained escalation; kung may consistent trend tulad ng madalas at mas malalaki pang rockfall events, at biglaang pagdami ng volcanic earthquakes natin, and significant increase of sulfur dioxide emission, and brighter and more persistent crater glow (For now, we maintain Alert Level 1 — the minimal level of activity of Mayon Volcano — and we will only raise it if there is clear and sustained escalation; if there is a consistent trend such as more frequent and larger rockfall events, a sudden increase in volcanic earthquakes, a significant increase in sulfur dioxide emissions, and a brighter and more persistent crater glow),” Bacolcol explained.