The  Philippine Institute of Volcanology and Seismology (Phivolcs) recorded at least 5 volcanic quakes from Kanlaon Volcano over a 24-hour period on Friday.

With that development, Phivolcs is maintaining Alert Level 1 over Kanlaon, which means that it is at an abnormal condition and “has entered a period of unrest.”

Phivolcs since January 30 has been recording at least one volcanic quake from Kanlaon in Negros Island.

According the agency’s bulletin posted on its website on Saturday morning, the agency also observed sulfur dioxide (SO2) emissions measured at an average of 467 tonnes/day on January 31, 2021, and slight deformation from its lower and middle slopes.

“Ground deformation data from continuous GPS measurements recorded a slight inflation of the lower and middle slopes since June 2020 followed by a pronounced inflation of the western middle slopes this November,” it said.

“Electronic tilt monitoring on the southeastern flanks likewise recorded inflation on the lower to middle slopes that began in late June 2020. These parameters may indicate hydrothermal or magmatic processes occurring deep beneath the edifice,” Phivolcs added.

“According to Google, “Magmatic processes include the generation of magmas by partial melting in the Earth mantle or crust, the evolution of magmas during ascent, storage and crystallization, and eruption of magmas at volcanoes on the Earth’s surface.”

On maintaining Alert Level 1, Phivolcs said: “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. 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 agency said it will continue to monitor Kanlaon Volcano.