The Philippine Institute of Volcanology and Seismology (PHIVOLCS) has recorded 35 volcano-tectonic earthquakes in Kanlaon Volcano in the past 11 hours.
In an advisory released on July 21, it said tjay the earthquakes, which ranged in magnitude from 0.9 to 2.3, occurred at depths of 12 to 15 kilometers beneath the summit crater.
Ground deformation data from continuous GPS and electronic tilt measurements have also been recording short-term inflation of the middle slopes of the volcano since March 2023, PHIVOLCS added.
Volcanic sulfur dioxide (SO2) gas emission from the summit crater averaged 786 tonnes/day on July 18, it said, which is 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, PHIVOLCS added.
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.