Pyroclastic, lahar flows expected as Mayon erupts
Phivolcs raises Alert Level 4 over Mayon Volcano, which means a ‘hazardous eruption’ is imminent and the danger zone is widened to a radius of 8 kilometers from the crater.
Alert Level 4 has been raised over Mayon Volcano as authorities monitored lava fountains reaching 500 meters above the crater, ash plumes that rose as high as 1,300 meters and a pyroclastic flow on Monday.
Undersecretary Renato Solidum Jr., officer-in-charge of the Philippine Institute of Volcanology and Seismology (Phivolcs), said in a press conference that the alert level was raised at 1 p.m. Monday.
This means that a hazardous explosion is imminent and the danger zone has been expanded to a radius of 8 kilometers, Solidum said.
Solidum warned against pyroclastic and lahar flows, which are more dangerous than the ashfall. Pyroclastic flow is defined as fluidized masses of hot volcanic rock fragments and gases while lahar is a type of mudflow composed of pyroclastic materials.
For lahar flow, the danger zone includes rivers and low-lying areas, especially during heavy rains.
In a situational report as of 8 a.m. Monday, January 22, the National Disaster Risk Reduction and Management Council (NDRRMC) said the seismic monitoring network for Mayon has monitored one incident of pyroclastic flow, 64 rockfall events and three episodes of volcanic earthquakes, included two that caused lava fountaining.
Ashfall was reported in the towns of Oas and Guinobatan in Albay. Ashfall has also reached the town of Polangui, Solidum said in the press conference.
The NDRRMC report said lava was “flowing more voluminously,” feeding the advancing Miisi lava flow and two other new lava flows in the Bonga Gully. The Miisi lava has advanced beyond 3 kilometers from the crater.
Following the increased volcanic activity, Albay Governor Al Francis Bichara on Monday cancelled classes in all levels in the entire province.
As of 6 p.m. Sunday, the NDRRMC reported that a total of 10,491 families, or 40,718 individuals, have been affected by the volcanic eruption. Some 6,498 families, or 24,611 persons, are staying in 27 evacuation centers while 734 families are being served outside the designated evacuation centers.