Mt. Kanlaon
MANILA – An increase in unrest, particularly in seismic activity, has been observed in Kanlaon Volcano, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Friday.
In an advisory, Phivolcs said 35 volcano-tectonic earthquakes were recorded from 10 p.m. Thursday to 9:06 a.m. Friday. These earthquakes, ranging from magnitudes 0.9 to 2.3, were 12 to 15 kilometers deep beneath the summit crater.
"This increase is significant since we only had an average of five earthquakes from July 1 to to 20," Phivolcs Director Teresito Bacolcol told the Philippine News Agency.
Volcano-tectonic earthquakes occur near or beneath volcanoes. These are produced when rocks beneath or around the volcano move due to pressure from magma.
Based on Phivolcs' advisory, the ongoing seismic activity indicates that fracturing at deeper levels is occurring and may possibly lead to further unrest.
Bacolcol, meanwhile, said a slight increase in sulfur dioxide (S02) emission, and short-term inflation (bulging) of the slopes of Kanlaon have also been observed.
Kanlaon's S02 emission averaged 786 tonnes on July 18, slightly higher than the average emission of 566 tonnes/day since March 2023, according to Phivolcs.
The volcano is still on Alert Level 1 (low-level unrest).
The public is advised to remain vigilant and refrain from entering the 4-km. permanent danger zone due to increased chances of sudden and hazardous phreatic eruptions.
Phivolcs also urge aviation authorities to advise pilots to avoid flying close to the volcano’s summit as debris or material from any sudden phreatic eruption can be hazardous to aircraft. (PNA)
