Manila: The Philippine Institute of Volcanology and Seismology (Phivolcs) on Saturday urged the public to maintain vigilance as Kanlaon Volcano has increased activity. Degassing is normal and usually happens in an active volcano but Mt. Kanlaon's restiveness has increased, according to Phivolcs Director Teresito Bacolcol. "This (degassing) doesn't always mean an eruption is coming, but it shows the volcano is restless and needs to be closely watched for signs of more activity," Bacolcol told the Philippine News Agency. Degassing means the volcano is releasing gases like sulfur dioxide. "Degassing happens when magma underground releases gases like sulfur dioxide, which escape through cracks," Bacolcol explained. Philvolcs recorded brief episodes of gray ash brought out by continuous degassing from the summit crater of Kanlaon. The 'ashing' events were observed at 6:41, 7:01 and 8:01 a.m., and lasted two to six minutes. No detectable seismic or infrasound signals of the events were recorded, but they gen erated light-gray plumes reaching 500 meters above the crater. Traces of ash were reported in the villages of Yubo and Ara-al in La Carlota City, and Sag-ang in La Castellana town. Sulfurous fumes were also experienced in Barangay Yubo. "Volcanic ash in the degassing plume signifies open vent conditions in which volcanic gas can carry fine debris from fractured rock or even from the margins of shallow magma beneath the edifice," Phivolcs said in its advisory. Alert Level 2 (increasing unrest) prevails over Kanlaon, and the current activity may lead to eruptive unrest and an increase in the alert level. "Phivolcs would like to reiterate that people living around Kanlaon Volcano should remain vigilant and be prepared for any possible escalation of activity. The no entry restriction to the four-kilometer permanent danger zone must be strictly observed," Bacolcol said. Source: Philippines News Agency