KANLAON VOLCANO ADVISORY

21 July 2023

10:00 A.M.   

This is a notice of increased seismic activity at Kanlaon Volcano.

A total of thirty-five (35) volcano-tectonic or VT earthquakes have been recorded by the Kanlaon Volcano Network between 10:00 PM, 20 July and 9:06 AM, 21 July 2023. These earthquakes ranged in energy from M_L0.9 to M_L2.3 and occurred at depths of 12 to 15 kilometers beneath the summit crater. Ground deformation data from continuous GPS and electronic tilt measurements have been recording short-term inflation of the middle slopes since March 2023. Volcanic sulfur dioxide (SO₂) gas emission from the summit crater averaged 786 tonnes/day on 18 July, 2023 slightly higher than the average emission of 566 tonnes/day since March 2023. While monitoring parameters in the past months have been consistent with shallow hydrothermal activity driven by degassing of deeper magma, ongoing VT earthquake activity indicates that fracturing at deeper levels is occurring and may possibly lead to further unrest.

The public is reminded that Alert Level 1 prevails over Kanlaon. Should the above uptrend in monitoring parameters persist, the volcano status may be raised to Alert Level 2 to warn of increasing unrest. The public and local government units are strongly advised to be vigilant and refrain from entering the four (4) kilometer Permanent Danger Zone (PDZ) due to increased chances of sudden and hazardous phreatic eruptions occurring without warning. 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. DOST-PHIVOLCS is closely monitoring Kanlaon Volcano’s activity and any new development will be relayed to all concerned.

DOST-PHIVOLCS