Taal Volcano in Batangas remained restive Wednesday as state volcanologists recorded at least 12 volcanic quakes in the last 24 hours.
In its Wednesday update, the Philippine Institute of Volcanology and Seismology (Phivolcs) also noted five volcanic quakes at Mayon and two at Bulusan.
"Taal Volcano’s seismic network recorded 12 volcanic earthquakes during the past 24 hours. Field measurements conducted yesterday at the western sector inside the Main Crater Lake showed that the water temperature increased from 30.1 to 31.8 degrees Celsius," it said in its recent update.
The agency said Alert Level 2 remains hoisted over Taal Volcano, which means magma has been intruding towards the surface.
Phivolcs maintained the main crater, Daang Kastila Trail and Mt. Tabaro, are strictly off-limits due to possible occurrences of sudden steam-driven explosions and high concentration of toxic gases, which can be lethal to both humans and animals and may cause damage to vegetation.
It also reminded the public that the entire volcano island is a Permanent Danger Zone (PDZ), and permanent settlement in the island is strictly not recommended.
Quakes at Mayon
In Albay, at least five volcanic quakes were recorded in the last 24 hours, along with weak to moderate steaming activity, with white steam clouds "creeping downslope towards northwest and west-northwest."
A fair crater glow that can be seen by the naked eye was also observed Tuesday night, it added.
Phivolcs said Alert Level 1 remains hoisted over Mayon Volcano.
"Although this means that no eruption is imminent, it is recommended that the public should not enter the 6-kilometer radius PDZ due to the continuing threat from sudden small explosions and rockfalls from the upper and middle slopes of the volcano," it said.
It added that active stream/river channels and those perennially identified as lahar-prone areas in the southern sector should also be avoided especially during bad weather conditions or heavy and prolonged rainfall.
Restive Bulusan
In Sorsogon, meanwhile, Phivolcs recorded two volcanic earthquakes around Bulusan Volcano during the past 24 hours.
Phivolcs also noted "wispy to weak white steam clouds" at the southeast thermal vents.
The volcano’s status remains at Alert Level 1, meaning the source of activity is hydrothermal and shallow.
"Entry to the 4-kilometer radius PDZ is strictly prohibited, since the area is at risk to sudden steam and ash explosions. Due to the prevailing wind direction, residents in the northwest and southwest sectors of the volcano are reminded to take precautions against ashfalls," the agency said.
Phivolcs said that civil aviation authorities must warn pilots to avoid flying close to the volcano’s summit —particularly on its western side— as ejected ash and volcanic fragments carried by the prevailing winds may cause damage to aircrafts.
People living near valleys and river/stream channels, meanwhile, should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall, it warned. — JMT/TJD