MANILAPhilippines – Albay province’s Mayon Volcano was raised to Alert Level 3 on TuesdayJanuary 6less than a week after being placed under Alert Level 2 on New Year’s Day.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said “very slow extrusion of shallow degassed magma is ongoing and is incrementally increasing in rate,” or an “effusive magmatic eruption is taking place.”

An effusive or non-explosive magmatic eruption is “dominated by the outpouring of lava onto the ground,” according to the United States Geological Survey (USGS)in contrast to an explosive eruption where there is “violent fragmentation of magma.”

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Phivolcs said the collapse of the lava domeor the lava that accumulated and solidified at Mayon’s summitgenerated pyroclastic density currents (PDCs) along the Bonga Gully on the southeast side of the volcano at 12:26 pm on Tuesdaytraveling down within 2 kilometers of the summit crater.

PDCs are made up of fragmented volcanic particlesgasesand ash that travel down volcanic slopes at high speeds. They can destroy or burn anything in their pathwith temperatures generally ranging between 200°C and 700°Caccording to USGS.

“Mayon is exhibiting magmatic eruption of a summit lava domewith increased chances of lava flows and hazardous PDCs or uson affecting the upper to middle slopes of the volcanoand of potential explosive activity within days or weeks,” Phivolcs further explained in its bulletinissued at 1:20 pm on Tuesday.

That also means there is now an “increased tendency towards a hazardous eruption.”

Evacuation from PDZ

Phivolcs recommended evacuation from the 6-kilometer-radius permanent danger zone (PDZ) surrounding Mayonciting “the danger of PDCslava flowsrockfallsand other volcanic hazards.” Ashfall and lahar flows may also occur.

Rockfalls in particular have spiked further in the early days of 2026with a total of 364 rockfall incidents recorded since New Year’s Daycompared to 599 from November to December 2025.

“The volume of discrete rockfallwith observed incandescence at nighttimeincreased yesterday (MondayJanuary 5)signaling an increase in the rate of dome growth and the onset of extrusion of new lava at the crater,” added Phivolcs.

Mayon’s eastern and southeastern slopes have also been inflated or swollen since June 2024.

Phivolcs said the following barangays — arranged under the city or municipality they belong to — have portions located within the 6-kilometer-radius PDZ:

• Tabaco City – OsonMarirocComonMagapoBuang
• Malilipot – CalbayogBarangay VSanta CruzCanaway
• Ligao City – Baligang
• Santo Domingo – Fidel SurtidaLidongSan FernandoSanta Misericordia
• Camalig – SuaTumpaAnolingQuirangay
• Daraga – Mi-isi
• Guinobatan – Doña Tomasa (Magatol)Muladbucad PequeñoMuladbucad Grande
• Legazpi City – MabinitBuyuanMatanagBongaPadang
• Bacacay – Bonga (Upper)

“They should follow the evacuation plan of their LGUs (local government units)and if there’s ash or sulfur dioxide (SO2)then they have to wear face masks,” Phivolcs Director Teresito Bacolcol said in a mix of Filipino and English during a press conference on Tuesday.

Scenarios

The last time Mayon was placed under Alert Level 3 was in June 2023also due to an effusive magmatic eruption. It was subsequently downgraded to Alert Level 2 in December 2023then Alert Level 1 in March 2024followed by the developments in the first week of January 2026.

The alert levels are from 1 to 5with 5 indicating that a hazardous eruption is already in progress.

Maria Antonia Bornaschief of Phivolcs’ Volcano Monitoring and Eruption Prediction Divisionsaid during Tuesday’s press conference that the “likely scenario [now] is the one similar to 2023,” although the intensity of Mayon’s current eruption is greater since there has been long-term ground deformation or swelling of the volcano’s edifice.

If the “slow lava dome and short lava flow extrusion” persistAlert Level 3 may be maintained for a few monthssimilar to what happened in 2023.

Howeverif Phivolcs observes “lava fountaining and lava flow with occasional explosions and PDCs within the PDZ,” as well as increased SO2 emissionconsiderably more volcanic earthquakesand swelling of the entire edificeAlert Level 4 would be raised.

“Anything can happen in a volcanoespecially one as active as Mayon. Meron din pong tsansa kasi na meron tayong panibagong intrusion habang pumuputok ang bulkan at ito po ay magdulot ng explosivity (There’s also a chance of new intrusion while the volcano is erupting and this may cause explosivity),” Bornas said. Magmatic intrusion refers to the rising of magma toward the surface.

The worst-case scenario would see the declaration of Alert Level 5when there is already an explosive eruption “with high-intensity lava fountaininglong lava flowsand PDCs on all sectors that could exceed the 6-kilometer PDZ,” as well as rapid escalation in SO2 emissionvolcanic earthquake activityand ground deformation. A sudden drop in SO2 can also be a warning sign because it could mean that gas cannot escape due to a blockage and pressure may build up inside the volcano.

Bornas said the worst-case scenario is the “least likely” onefor nowbased on current parameters observed by Phivolcs. – Rappler.com