BACOLOD City – The Philippine Institute of Volcanology and Seismology (Phivolcs) is closely monitoring the activity of the Kanlaon volcano after they recorded a spike in volcanic earthquakes.
A total of 35 volcanic-tectonic tremors were recorded by the Kanlaon Volcano Network between 10 p.m. on Thursday, July 20, and 9:06 a.m. on Friday, July 21, according to a Phivolcs advisory.
The energy of the earthquakes ranged between magnitude 0.9 to magnitude 2.3 and occurred at depths of 12 to 15 kilometers beneath the summit crater.
Kanlaon straddles the provinces of Negros Occidental and Negros Oriental, approximately 30 kilometers southeast of Bacolod City, the capital and most populous city of Negros Occidental and the whole island.
Volcanologists have also noted ground deformation from continuous global positioning system (GPS), and electronic tilt measurements recorded short-term inflation of the middle slopes of the volcano since March this year.
They also recorded a higher amount of sulfur dioxide gas emission from the summit, averaging 786 tonnes per day on July 18, slightly higher than the average emission of 566 tonnes per day back in March.
Phivolcs said the ongoing volcano-tectonic earthquakes may indicate that fracturing at deeper levels is occurring and may possibly lead to further unrest.
At present, Kanlaon remains under Alert Level 1, although Phivolcs noted that should the uptrend in monitoring parameters persist, they may raise the volcano’s status to Alert Level 2 to warn of increasing unrest.
The public and local government units are advised to be vigilant and refrain from entering the four-kilometer permanent danger zone 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.
Kanlaon is a stratovolcano and the highest mountain on the island of Negros, as well as the highest point in the Visayas, with an elevation of 2,465 meters (8,087 feet) above sea level. (Watchmen Daily Journal)
