Alert Level 3 over Mayon volcano, hazardous eruption within weeks or even days still possible, Philippines

PHIVOLCS maintains Alert Level 3 over the Mayon volcano, which means that it is currently in a relatively high level of unrest, and hazardous eruption within weeks or even days could still be possible.

In 24 hours to 00:00 UTC on October 3, 2023, the Mayon Volcano Network recorded 6 volcanic earthquakes and 111 rockfall events. The lava flows have maintained their advances to approximately 3.4 km (2.1 miles) in Bonga (southeastern), 2.8 km (1.7 miles) in Mi-isi (south), and 1.1 km (0.7 miles) in Basud (eastern) Gullies.

Rockfalls and pyroclastic flows (PDCs) generated by collapses of the lava flow margins as well as of the summit dome deposited debris still within four 4 km (2.5 miles) of the crater.

Volcanic sulfur dioxide (SO₂) emission averaged 1 390 tonnes/day on October 2.

Short-term observations from electronic tilt and GPS monitoring indicate continued inflation of the northwestern upper slopes since the fourth week of July 2023. Meanwhile, electronic tilt measurements show slight deflation on the northwestern middle slope starting in the third week of September.

Longer-term ground deformation parameters from EDM, precise leveling, continuous GPS, and electronic tilt monitoring indicate that Mayon is still generally inflated relative to baseline levels.

PIVOLCS recommends that the 6 km (3.7 miles) radius Permanent Danger Zone (PDZ) remain evacuated due to the danger of PDCs, lava flows, rockfalls, and other volcanic hazards.

Increased vigilance against PDCs, lahars, and sediment-laden streamflows along channels draining the edifice is also advised.

Heavy rainfall could generate channel-confined lahars and sediment-laden streamflows in channels where PDC deposits were emplaced. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft. Based on the current prevailing wind pattern, ash fall events may most likely occur on the south side of the volcano.

A total of 9 876 families or 38 396 persons are affected in 26 barangays in Albay.

References:

¹ Mayon Volcano Bulletin – PHIVOLCS – October 3, 2023 at 00:00 UTC

Featured image credit: Copernicus EU/Sentinel-2, EO Browser, The Watchers. Acquired on September 26, 2023