Manila, Jan 26 (IANS) Philippine authorities on Sunday downgraded the alert level for Taal Volcano fromin response to reduced activity 15 days after it erupted.
But the Institute of Volcanology and Seismology warned that the lowering of the alert level from four to three does not mean that the threat of a hazardous eruption has disappeared, reports Xinhua news agency.
Taal Volcano erupted on January 12, prompting the institute to raise the alert level to four on a scale of five. Level four indicates the eruption could occur within days, and level five means a hazardous eruption is in progress.
Renato Solidum, the head of the volcanic institute, announced that the alert level for the island volcano, about 66 km south of Manila, was lowered due to “decreased tendency towards hazardous eruption”.
The institute said Taal’s condition in the two weeks following the phreatomagmatic eruption “has generally declined into less frequent volcanic earthquake activity, decelerated ground deformation of the Taal Caldera and Taal Volcano Island (TVI) edifices and weak steam/gas emissions at the main crater”.
“Alert level three means that there is a decreased tendency towards hazardous explosive eruption but should not be interpreted that unrest has ceased or that the threat of a hazardous eruption has disappeared,” it added.
Should an uptrend or pronounced change in monitored parameters forewarn a potential hazardous explosive eruption, the institute said alert level may be raised back to four.
The institute warned that “sudden steam-driven and even weak phreatomagmatic explosions, volcanic earthquakes, ashfall and lethal volcanic gas expulsions can occur and threaten areas within the volcano and nearby lakeshores.”
It also advised pilots to avoid flying close to the volcano as airborne ash and ballistic fragments from sudden explosions and wind-remobilized ash may pose hazards to aircraft.
More than 300,000 residents have been evacuated to safer grounds.