Manila: Residents around Kanlaon Volcano are advised to be vigilant due to increased seismicity and long-duration tremors observed over the past 24 hours, the head of the Philippine Institute of Volcanology and Seismology (Phivolcs) said Monday. At least 150 volcanic earthquakes, including four volcanic tremors with 40 to 100 minutes duration, were recorded.

According to Philippines News Agency, Phivolcs Director Teresito Bacolcol noted in an interview that the increased number of earthquakes, including several long-duration tremors, indicates that the volcano remains active internally. Bacolcol emphasized that these developments show the volcano "is not quiet," urging residents in the vicinity to remain vigilant.

Bacolcol confirmed that Kanlaon Volcano exhibits continued internal activity, and Alert Level 2, signifying increased unrest, is maintained over the volcano. He clarified, however, that not all tremors lasting more than an hour are automatically unusual, as some volcanic tremors can extend over several hours or even days. For instance, a volcanic tremor in Taal persisted for 221 days from July 2021 to February 2022, and several tremors in Taal Volcano last year continued for a few days.

For areas near Kanlaon, Bacolcol reiterated that the 4-kilometer radius permanent danger zone (PDZ) should remain a no-entry zone even at Alert Level 0, as sudden hazardous events, like phreatic eruptions, could occur without warning. He acknowledged that some residents inside the PDZ might not be able to leave due to their livelihoods being tied to the area. Despite this, he stressed that the PDZ is not meant for permanent settlement due to its inherent hazards.