Volcanic earthquakes indicating magma ascending to the crater were detected 24 times. Tremors from the on-rushing lava registered a record-high 431 times.
Mayon rested for about two days. But with the resurgence of its high-level unrest, volcanologists said it is too early to tell whether the country’s most active volcano is set for a bigger explosion or simmering down.
"It is in fact dangerous to declare this early that Mayon is already simmering down because its eruption history tells us the opposite," Alex Baloloy of the Philippine Institute of Volcanology and Seismology (Phivolcs) told The STAR.
Baloloy recalled that during its eruption on Feb. 2, 1993, Mt. Mayon ejected a deadly pyroclastic flow without precursors that could have served as a warning for the 78 farmers who were engulfed by the 600-degree Celsius hot gas and solid volcanic debris.
He noted that the countdown on Mayon’s simmering activity, for the purpose of lowering its present alert level from 4 to 3, always goes back to square one whenever the 2,462-meter volcano exhibits fluctuating readings in the parameters of its abnormality.
Mayon’s latest mild explosions were detected by seismographs at 6:08 p.m., 7:41 p.m., 8:51 p.m., 8:53 p.m. and 10:45 p.m. Monday, and at 2:38 a.m. yesterday, Phivolc’s latest bulletin said.
Although the sulfur dioxide emission dropped to 2,445 tons yesterday from 5,390 tons Monday, the rate of lava extrusion and volume of rock falls had increased anew with related tremors reaching 431, the bulletin said.
Phivolcs science researcher Reymond Maximo said Mayon’s high level of unrest remains as long as its parameters are not consistently lowering in value and interpretations.
Mayon has mildly exploded over 60 times since last Aug. 7, the same day it displayed a series of ash ejection that prompted Phivolcs to raise its alert level to 4.
"At this point, parameters are not following a consistent downward pattern yet. What we can observe instead is fluctuation in the visual and instrument-detected abnormal indicators," Maximo said.
As this developed, disaster management and local officials here are experiencing difficulties at convincing people not ordered for forced evacuation to leave congested refugee camps and go back to their homes.
Cedric Daep, Albay’s chief of the Provincial Disaster Management Office, said they have tapped concerned local officials to convince their constituents, whose houses are not under threat by Mayon, to decamp and go back home.
"In the first place, we have furnished these concerned local officials the list of barangays ordered for mandatory evacuation from day one of the order. But probably because of fear, even those not within the threatened villages voluntarily evacuated," Daep said.
Jess Llabore, councilor of Daraga in Albay tasked to oversee the welfare of evacuees in the town, said that they are having a hard time sending residents not threatened by Mayon’s activity home.
"If you force them, they get angry," Llabore told The STAR. — Cet Dematera