MANILA, Philippines – At least 288 volcano-tectonic (VT) earthquakes have been recorded at Kanlaon Volcano in Negros Island since midnight of Tuesday, September 10, based on an advisory issued at 11 am.
The VT earthquakes were 0 to 9 kilometers deep, “beneath the northeastern flanks of the volcanic edifice,” said the Philippine Institute of Volcanology and Seismology (Phivolcs).
“VT earthquakes are generated by rock fracturing processes and the increase in VT activity strongly indicates progressive rock fracturing beneath the volcano as rising magma drives a path towards the surface,” Phivolcs said.
According to the agency, the strongest of these VT earthquakes were felt at Intensity II in parts of Canlaon City, Negros Oriental.
Some residents of Bago City, Negros Occidental, reported “rumbling sounds.”
There were also “strong sulfur fumes” in a few barangays in the cities of Canlaon, Bago, and La Carlota. La Carlota City is in Negros Occidental.
On Monday, September 9, there was also a spike in the number of VT earthquakes, with Phivolcs recording a total of 37. Almost all of these happened from 10:35 pm to midnight.
Phivolcs reiterated its warning from late Monday evening that “current seismic activity may lead to eruptive unrest and an increase in the alert level.”
Kanlaon Volcano has been under Alert Level 2 since its June 3 eruption, which was its first eruption since December 2017 and the 43rd recorded since 1866.
Alert levels range from 0 (normal) to 5 (hazardous eruption in progress).
“The public is strongly advised to be ready and vigilant, and to avoid entry into the 4-kilometer-radius permanent danger zone to minimize risks from volcanic hazards such as pyroclastic density currents, ballistic projectiles, rockfall, and others,” the agency said on Tuesday morning.
Ashfall and lahar flows remain possible as well. – Rappler.com