MANILA, Philippines — After rockfall increase since June 3, Phivolcs put Mayon Volcano on Alert Level 3 on Thursday due to “potential explosive activity happening within days or weeks.”
Phivolcs, in a bulletin, said that the “volume of discrete rockfall events increased on 3 June based on the seismic record, signaling an increase in the rate of dome growth.”
Phivolcs reported three pyroclastic density current (PDC) events on Bonga and Basud Gullies at 6:18 a.m., 9:53 a.m. and 11:00 a.m.
The PDCs lasted 4-5 minutes and occurred within a kilometer of the summit crater. On the other hand, SO2 (sulfur dioxide) emissions remained at baseline levels.
The agency warned that Mayon is exhibiting magmatic eruption, a potential explosive activity within weeks or days.
“In view thereof, Phivolcs-DOST is now raising the alert status of Mayon Volcano from Alert Level 2 to Alert Level 3. This means that Mayon is exhibiting magmatic eruption of a summit lava dome, with increased chances of lava flow and hazardous PDCs affecting the upper to middle slopes of the volcano and of potential explosive activity within weeks or even days,” Phivolcs said.
PDCs, lava flows, rockfalls, and other risks call for evacuating the Permanent Danger Zone within 6 km. Pyroclastic density currents, lahars, and sediment-laden streamflows along volcano channels should be monitored, Phivolcs said.
Aside from the rockfall, residents observed ash fall over Legazpi City and Daraga in Albay.
Miladee Azur, head of the city’s disaster risk reduction and management office, said residents in the villages of Cruzada, Baño, and others reported that they noticed the thin layer of ash on their vehicles.
In Daraga town, Armel Alcantara, 59, a resident of Barangay Gapo, also noticed his solar panels and car covered with ash when he woke up around 6 a.m.
Paul Karson Alanis, a volcanologist at Phivolcs-Legazpi, observed the ashfall at their office on Ligñon Hill in Barangay Bogtong in the city.
Alanis said the wind carried the ash south of the volcano, facing the city and towns of Daraga and Camalig.
Last June 5, Phivolcs raised Alert Level 2 over Mayon due to the rockfalls observed since January 2023.
The Civil Aviation Authority of the Philippines also issued a notice to airmen, barring planes from flying within 10,000 feet above the surface of Mayon Volcano.