Mayon volcano gets facelift with new lava dome

LEGAZPI CITY, Philippines — Mayon Volcano has received a facelift.

A new dome has formed after the recent volcanic unrest that started last Jan. 13 replaced the old lava dome at the crater from the 2014 eruption.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said Alert Level 3 remains in effect over Mayon, which means it is currently at a relatively high level of unrest as magma is at the crater and hazardous eruption is possible within weeks or even days. 

Lava effusion from the summit’s new lava dome and lava collapse events characterized Mayon Volcano’s eruptive activity in the past 24 hours. 

Phivolcs director Renato Solidum said Mayon’s activity could further escalate and lead to a hazardous eruption. 

Solidum said Mayon has repaired her damaged feature like a facelift at the southern flank because of continuous lava flow.

Phivolcs had recorded 48 rockfall events, two pyroclastic density currents and one volcanic earthquake. 

Rockfall events were generated by the collapsing lava front and advancing lava flow on the Miisi Gully and by shedding from the summit dome on the Matanag and Buyuan Gullies.

Currently, the Miisi lava flow has advanced to approximately three kilometers from the summit crater while pyroclastic density currents were within the six-kilometer permanent danger zone. 

The volcano is also spewing ash clouds that drift to the southwest portion of Mayon. 

Sulfur dioxide gas emission was measured at an average of 1,159 tons a day last Wednesday.

Solidum told reporters yesterday at the Albay provincial capitol that Mayon’s present activity could be described as lava eruption or non-explosive magmatic eruption. 

The current activity is similar to the 2006 and 2009 eruptions but different from the very short-lived 2014 eruption, he added.

He said the current condition “based on our monitoring of earthquake, gas and ground deformation so far indicate no measurable change as of the present. So we will maintain it alert level No. 3.”

Solidum said the other scenario that should be considered is when the volcano moves to an explosive eruption, which could happen if lava has a lot of gas or if the lava would de-gas and cover the vent of the volcano or conduit, preventing gas from escaping and leading to over-pressurization.

The second scenario is similar to the unrest in the years 2000 to 2001, 1984 and 1968 for the first phase of the eruption, where lava flow was followed by explosive eruption, Solidum said.

“But again the current monitoring parameters indicate no change right now towards this scenario, but we need to continue monitoring the volcano,” he added.

He said if there is over-pressurization of gas, Phivolcs could raise the Alert Level from 3 to 4, which would also expand the danger zone from the curent seven-kilometer radius from the volcano.

Evacuation

The Department of Social Welfare and Development (DSWD) reported that over 36,000 residents have been evacuated and are now in 32 evacuation centers in Camalig, Daraga, Guinobatan, Malilipot, Sto. Domingo and the cities of Legazpi, Ligao and Tabaco.

Solidum said based on the aerial survey conducted over Mayon, lava flow is moving southward.

The aerial survey confirmed that only lava flows are happening and there are no explosive deposits or pyroclastic flow in other areas. 

Lava flow is mainly concentrated at the southern flank, consistent with recommendations for the extended danger zone in this quadrant. 

Solidum said Mayon could eject an estimated 75 million cubic meters of volcanic materials in case of a full-blown eruption. – Christina Mendez, Rhodina Villanueva, Rainier Allan Ronda, Cet Dematera