Local government units in Negros Island are on alert for a possible Kanlaon Volcano eruption after it was rocked by 288 volcano-tectonic (VT) earthquakes from Monday to Tuesday.
The increase in the VT activity at Kanlaon strongly indicates progressive rock-fracturing beneath the volcano as rising magma drives a path towards the surface, the Philippine Institute of Volcanology and Seismology (Phivolcs) warned on Tuesday.
Volcanic sulfur dioxide (SO2) gas emission from the summit crater was 9,985 tons on Tuesday, Phivolcs also reported.
It was the highest emission from the volcano recorded since instrumental gas monitoring began, it said.
Mayor Jose Chubasco Cardanas said he ordered the immediate mandatory evacuation of residents still living within the 4-kilometer Permanent Danger Zone (PDZ) in Canlaon City, Negros Oriental, due to the imminent threat posed by Kanlaon Volcano.
The Canlaon City Disaster Risk Reduction and Management Office is tasked to facilitate the safe and orderly transfer of residents to the designated evacuation centers located outside the danger zone, he said.
The LGU will provide food, water, medicines, and other necessities at these centers, Cardenas assured.
Mayor Rhummyla Mangilimutal cancelled classes at all levels in both public and private schools in La Castellana, Negros Occidental, on Tuesday.
She also reminded residents living in the upper barangays of La Castellana not to enter the 4-kilometer PDZ.
Residents living near the volcano have been alerted of a possible eruption, she said, adding that she was convening the Municipal Disaster Risk Reduction Management Council to ensure that their response measures to a possible eruption are in place.
Negros Occidental Gov. Eugenio Jose Lacson stressed the need for continued vigilance.
Lacson said he hopes the situation at Kanlaon Volcano improves so there will be no need for forced or massive evacuation.
A Phivolcs advisory at 11 a.m. Tuesday said the 288 VT earthquakes were generated between 0 to 9 kilometers depths beneath the north-eastern flanks of the volcanic edifice and the strongest events were felt at Intensity II in some barangays of Canlaon City.
Rumbling sounds were reported by some Bago City residents, it added.
Sulfuric odors were reported in Brgy. Ilijan, Bago City; Brgy. Ara-al and Brgy. San Miguel, La Carlota City; and Brgy. Masulog, Brgy. Linothangan and Brgy. Pula, Canlaon City, Phivolcs said.
Prolonged exposure to volcanic SO2, especially in communities within direct reach of accumulation from Kanlaon plumes during low wind conditions, can cause irritation of the eyes, throat and respiratory tract, Phivolcs said.
The public is reminded that Alert Level 2 (increasing unrest) prevails over Kanlaon, but that current seismic activity may lead to eruptive unrest and an increase in the Alert Level, Phivolcs also said.
The public is strongly advised to be ready and vigilant, and to avoid entry into the 4 kilometer-radius PDZ to minimize risks from volcanic hazards such as pyroclastic density currents, ballistic projectiles, rockfall and others, it added.
In case of ash fall events that may affect communities downwind of Kanlaon’s crater, people should cover their nose and mouth with a damp, clean cloth or dust mask, Phivolcs said.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash and ballistic fragments from sudden eruption can be hazardous to aircraft, it said.
Communities living beside river systems on the southern and western slopes, especially those that have already experienced lahars and muddy streamflows, are advised to take precautionary measures when heavy rainfall over the volcano has been forecast or has begun, Phivolcs added.*