AFTER seven months, the Philippine Institute of Volcanology and Seismology (Phivolcs) has again strictly prohibited entry into the four-kilometer permanent danger zone (PDZ) around Bulusan Volcano in Sorsogon after Alert Level 1 was raised when it shook over a hundred times in the past days.
Phivolcs’ latest bulletin showed at least five volcanic earthquakes during the past 24-hour monitoring period while its upper slopes remained bulging or inflated.
These parameters, according to the agency, generally indicate that “shallow hydrothermal processes” are occurring beneath the edifice.
“Local government units and the public are reminded that entry into the four-kilometer radius permanent danger zone (PDZ) must be strictly prohibited and that vigilance in the two-kilometer extended danger zone (EDZ) on the southeast sector must be exercised due to the increased possibilities of sudden and hazardous phreatic eruptions,” the Phivolcs’ advisory said.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be hazardous to aircraft, it added.
The institute also cautioned people living within valleys and along river or stream channels, especially on the southeast, southwest and northwest sector of Mt. Bulusan’s edifice “to be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall should phreatic eruption occur”.
Phivolcs lifted all alert levels over Bulusan Volcano on October 26 last year after all its abnormal parameters went back to baseline levels.
But after some 120 volcanic earthquakes were recorded in the past days, Phivolcs again raised Alert Level 1 last May 11. Philippine News Agency