Alert level 1 remains at Bulusan Volcano in Sorsogon after state volcanologists noted a significant rise in seismic activity in the area, recording 144 volcanic quakes there in the last 24 hours.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said 80 of these quakes were recorded in a seven-hour period on Monday, from 5:00 a.m. to noon.
“The seismic network at Bulusan Volcano detected a total of 144 volcanic earthquakes for the past 24 hours. Steaming activity at the active vents was weak to moderate throughout the observation period,” Phivolcs said in its Tuesday update.
Phivolcs warned of possible sudden steam-driven or “phreatic” explosions.
“Similar events are most likely to occur in view of the volcano’s reactivation last 13 May 2011 especially with the current increase in the volcano’s seismicity,” it said.
However, it said Bulusan Volcano’s status remains at Alert Level 1, meaning sudden steam and ash explosions can occur.
Entry to the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited, since the area is at risk to sudden steam and ash explosions, it added.
“Due to the prevailing wind direction, residents in the northwest and southwest sectors of the volcano are reminded to take precautions against ashfalls. Civil aviation authorities must also warn pilots to avoid flying close to the volcano’s summit as ejected ash and volcanic fragments from sudden explosions may be hazardous to aircraft,” it said.
Phivolcs said aircraft should avoid flying on the western side of the volcano as volcanic debris are likely to be carried in this direction by the prevailing winds.
Also, it said people living near valleys and river/stream channels should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall.
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