MANILA, Philippines – Mayon Volcano was raised to Alert Level 1 on Sunday, August 21, as it “entered a period of unrest.”

The Philippine Institute of Volcanology and Seismology (Phivolcs) said in a bulletin on Sunday afternoon that the volcano in Albay province is now exhibiting “low-level unrest,” after it had stayed under Alert Level 0 or in a “normal” condition since July 30, 2021.

Phivolcs observed that the remnant lava dome from Mayon Volcano’s 2018 eruption underwent “a change in morphology” or structure and “slight extrusion” – or it was being forced out – between June 6 and Saturday, August 20.

There has also been a “slight short-term inflation” or swelling of the volcano edifice since April.

These mean that “volcanic gas-induced pressurization at the shallow depths of the edifice may be occurring, causing the summit dome of Mayon to be pushed out.”

In contrast, sulfur dioxide emissions and volcanic earthquakes remain at baseline levels. Phivolcs said there were only “short-lived spikes” in the number of volcanic earthquakes on May 26 and June 20.

What to do

Phivolcs reminded the public not to enter the 6-kilometer permanent danger zone around Mayon Volcano.

The following could “occur without warning”:

• sudden steam-driven or phreatic eruptions
• rockfalls
• avalanches
• ash bursts

Lahar might also form during periods of heavy rain. – Rappler.com