LEGAZPI CITY, Albay, Philippines — No volcanic earthquakes were recorded in Mayon Volcano a week after its warning status was raised to Alert Level 1, but the Philippine Institute of Volcanology and Seismology (Phivolcs) said other parameters indicated that the volcano remained in an abnormal condition.
Paul Karson Alanis, resident volcanologist of the Mayon Volcano Observatory Station at Ligñon Hill here, said the slight inflation and the expansion of the lava dome were signs that the volcano had entered a “period of unrest.”
“We have to emphasize that we do not only base it on volcanic earthquakes. It doesn’t mean that it is quiet. There is inflation, which means it is in abnormal condition,” Alanis said in a phone interview on Monday.
He said they were closely monitoring the lava dome at the summit crater that could collapse and generate pyroclastic flow and rock fall down the slopes of Mayon Volcano, which straddles eight localities in Albay province, namely, the capital city of Legazpi, the cities of Tabaco and Ligao, and the towns of Daraga, Camalig, Guinobatan, Malilipot and Sto. Domingo.
Alanis earlier said the gas rising from deep inside the volcano was continuously pushing out the remnant magma of the 2018 eruption.
“There was no indication of fresh magma, but the volcanic gas from the edifice is moving upward,” he said.
Crater glow
In the latest Phivolcs’ monitoring, the volume of the lava dome at the summit crater was estimated at 75,000 cubic meters.
Based on the bulletin released on Monday, Phivolcs observed a faint crater glow, which was visible using a telescope, and moderate emission measuring at least 500 meters drifting north-northwest and northwest.
Alanis said the crater glow has been consistently observed since 2018.
Cedric Daep, head of the Albay public safety and emergency management office, said local governments were directed to update the master list of the population that may be at risk, including the residents and the farmers cultivating land within the six-kilometer-radius permanent danger zone.
Mayon has been under alert level zero (normal) for more than a year before its status was raised to alert level 1 on Aug. 22 after it showed signs that the lava dome at the crater was growing and could collapse anytime.
Daep said disaster officials and village chiefs of localities surrounding the foot of the volcano were already asked to prepare their evacuation and other emergency plans.
RELATED STORIES
Lava dome collapse feared in Mayon Volcano
Albay bans activities inside Mayon Volcano danger zone
Phivolcs places Mayon Volcano under Alert Level 1