Phivolcs raises alert level 2 in Mayon Volcano

Mayon Volcano eruption on December 29, 2009. Tryfon Topalidis / Wikipedia photo

MANILA — The Philippine Institute of Volcanology and Seismology (Phivolcs) on Friday raised alert level 2 for Mayon Volcano in Albay province due to the observations indicating the advent of quiet lava intrusion that could lead to “greater unrest.”

In its advisory, Phivolcs is raising the alert level of Mayon Volcano from Alert Level 1 to Alert Level 2 which means that magma is intruding at depth and that current conditions may eventually lead to a larger eruption.

Phivolcs’ alert level system, “2” means increasing unrest.

It said the unrest is “probably of magmatic origin” and could eventually lead to eruption.

There is a possibility the 6-km radius Danger Zone may be extended to 7 km in the sector where the crater rim is low.

The agency is “strongly” advising the public to be vigilant and desist from entering the six (6) kilometer-radius Permanent Danger Zone (PDZ) to minimize risks from sudden explosions, rockfall and landslides.

Based on the observation of the Phivolcs last August 12, Mayon Volcano’s summit crater has growth of a new lava dome approximately 30m-50m high.

This event was preceded by inferred low-volume intrusions, signified by: (a) episodes of very slight inflation or swelling of the middle slopes of the edifice since the 7 May 2013 phreatic eruption, based on Precise Leveling, continuous tilt and continuous GPS measurements, and; (b) significant increases in SO2 flux beyond the baseline level of 500 tonnes/day, based on campaign and continuous gas measurements for the past two months.

Other monitored parameters such as the occurrence of volcanic earthquakes and rockfall, however, have remained at baseline levels, while almost no crater glow or banaag has been detected in the last four months.

”The growth of the new summit dome, slight ground deformation and increased volcanic gas emission likely signify the slow intrusion and degassing of magma. The absence of other outstanding precursors may be due to very low magma intrusion rates. Based on Mayon’s behavior exhibited in recent eruptions, current observations may indicate the advent of quiet lava extrusion that may eventually lead to greater unrest,” it said.

Phivolcs maintains close monitoring of Mayon Volcano and any new development will be communicated to all concerned stakeholders.