By Alexandria Dennise San Juan
More than a hundred earthquakes were recorded at Kanlaon Volcano in Negros Island, while white steam emission was observed from its vent during a 24-hour period, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Tuesday.
In its latest volcano bulletin, Phivolcs said Kanlaon’s seismic monitoring network noted a total of 104 volcano-tectonic earthquakes on the western flanks of the volcano.
One of the tremors, which occurred at 5:07 a.m. on Monday, was recorded at Magnitude 3 by the Philippine Seismic Network and was felt at Intensity II in La Carlota City, Negros Occidental.
Weak emission of steam-laden plumes rising 300 meters high has also been observed in Kanlaon’s vent before drifting northwest and southeast, while sulfur dioxide emission was measured at an average of 438 tonnes per day on June 13, Phivolcs added.
The state volcanology agency explained that hydrothermal or magmatic activity is occurring beneath Kanlaon’s edifice, as indicated by “slight deflation of the lower and mid slopes since January this year, and the continuing deflation on the lower slopes but inflation on the mid slopes since April, 2020.”
Alert Level 1 prevails over Kanlaon Volcano which means that it is in an abnormal condition and has entered a period of unrest.
According to Phivolcs, at this level, there is a slight increase in volcanic earthquake and steam or gas activity, as well as slight inflation or swelling of the edifice.
Phivolcs reminded local government units and the public that entry into the four-kilometer radius permanent danger zone must be “strictly prohibited” due to the further possibilities of sudden and hazardous steam-driven or phreatic eruptions.
Civil aviation authorities 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, the bureau added.
On Monday, Phivolcs announced that it is keeping Kanlaon Volcano under close watch following a series of earthquakes that was monitored in the area.
Phivolcs assured the public and nearby communities that it is closely monitoring the condition of the volcano and will inform authorities on further developments.