THE Kanlaon Volcano in Negros Island ejected ash and emitted steam, following a phreatic eruption over the weekend, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported.
The agency, in its Kanlaon Volcano Bulletin on December 10, said seismic monitoring network recorded three volcanic earthquakes during the past 24 hours.
On Saturday morning, a low-energy phreatic eruption occurred.
The Phivolcs recorded an explosion-type earthquake that lasted for about 10 minutes.
The event ejected dark ash and voluminous steam at three to four kilometers above the summit vent. It was accompanied by rumbling sound heard event up to La Castellana, Negros Occidental.
Phivolcs further reported that thin ashfall was experienced at Sitio Guintubdan in Barangay Ara-al in La Carlota City, Barangay Sag-ang in La Castellana, and Barangay Ilijan in Bago City -- all in Negros Occidental.
Degassing at the summit was also observed and detected through continuous low-energy tremor during periods when the summit was not visible, the agency said.
“Ground deformation data from continuous global positioning system (GPS) measurements indicate slight inflation of the edifice since December 2015,” it added.
Amid the recent activity, Mount Kanlaon remains under Alert Level 2 which means the volcano is undergoing a moderate level of unrest.
Under this alert level, there is probable intrusion of magma at depth which may lead to a magmatic eruption.
Phivolcs again reminded local government units, and the public as well, that entry in the four-kilometer radius permanent danger zone is strictly prohibited due to the possible sudden and hazardous phreatic eruptions.
The Civil Aviation Authorities of the Philippines must also advise pilots to avoid flying close to the volcano’s summit as ejecta from any sudden phreatic eruption can be hazardous to aircraft, it said.
Following the incident, the Bago City Disaster Risk Reduction and Management Office and City Health Office implemented Rapid Damage Assessment and Needs Analysis in Barangay Ilijan yesterday.
The team conducted ocular inspection, including interviews with the affected community.
The city’s Health Emergency Management Staff also distributed masks to residents in the area.
From Alert Level 1, the Alert Level 2 status was first raised over the volcano last November 15, after Phivolcs recorded a total of 279 volcanic earthquakes for the past 24 hours during that time.
After which, authorities have been closely monitoring the activities of Mt. Kanlaon, which is an active volcano.
The Provincial Disaster Management Program Division (PDMPD) had earlier said that Negros Occidental will be affected should the volcano erupt. Contingency plan, however, is already in place.
Directly affected under the four-kilometer danger zone are the cities of San Carlos, Bago, and La Carlota and the towns of Murcia, La Castellana, Moises Padilla and Salvador Benedicto, the PDMPD added.
The Office of Civil Defense in Negros Island had earlier prepared a comprehensive contingency plan for Mount Kanlaon.
Data showed that not less than 11,000 residents from five villages of Canlaon City may be affected if the volcano’s abnormalities will worsen.
If the volcano’s status will be raised to Alert Level 3, about 20,000 individuals from five villages of La Castellana will be affected.
If Alert Level 4, 2,500 households from five villages in La Carlota City; more than 500 households from two villages in Bago City; and one village in Murcia town will be affected.
Two villages in San Carlos City will also be hit if Alert Level 5 prevails, the agency added.