Kanlaon Volcano (DOST photo)
MANILA, Philippines — A total of 136 volcano-tectonic earthquakes have been recorded from the western flanks of Kanlaon Volcano in Negros Occidental in the last 24 hours as it emitted white steam-laden plumes, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Monday.
Four of the earthquakes that happened at 1:01 a.m., 1:04 a.m., 1:34 a.m., and 2:06 a.m. were recorded by the Philippine Seismic Network at magnitudes that range from 3.2 to 4.7, Phivolcs said in its 8 a.m. bulletin.
The said earthquakes were felt at Intensities II to V in La Carlota City and Bago City, Negros Occidental and Canlaon City, Negros Oriental.
“Activity at the vent consisted of moderate emission of white steam-laden plumes that rose 200 meters before drifting southwest. Sulfur dioxide emission was measured at an average of 438 tonnes/day on 13 June 2020,” said Phivolcs.
“Ground deformation data from continuous GPS (global positioning system) measurements indicate a slight deflation of the lower and mid slopes since January 2020. Short-term electronic tilt monitoring on the southeastern flanks recorded continuing deflation on the lower slopes but inflation on the mid slopes since April 2020,” it added.
Phivolcs said these parameters indicate that hydrothermal or magmatic activity is occurring beneath the surface.
“Kanlaon Volcano is at Alert Level 1 which means that it is at an abnormal condition and has entered a period of unrest. The local government units and the public are strongly reminded that entry into the 4-kilometer radius Permanent Danger Zone (PDZ) must be strictly prohibited due to the further possibilities of sudden and hazardous steam-driven or phreatic eruptions,” Phivolcs said in its Monday morning advisory.
Phivolcs said civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ejecta or materials spewed from any sudden phreatic eruption poses aviation risks.
Kanlaon is located between the borders of Negros Oriental and Negros Occidental.
At 2,465 meters above sea level, it is the highest point in Negros Island and in the Visayas.