Kanlaon hit by new earthquake swarm
BACOLOD CITY—Kanlaon Volcano experienced another swarm of volcano-tectonic (VT) earthquakes on its northwestern flank that may lead to a moderate eruption, a state volcanologist said on Monday.
“But while there is always a chance of a moderate eruption, it doesn’t mean it will follow immediately after the VT swarms,” said Ma. Antonia Bornas, chief of the Philippine Institute of Volcanology and Seismology (Phivolcs) Volcano Monitoring and Eruption Prediction Division.
The Kanlaon Volcano Network recorded 72 VT earthquakes between 12 a.m. Sunday and 8 a.m. Monday, up by 31 from the 41 VT quakes previously reported.
Bornas noted these earthquakes were relatively strong, with magnitudes ranging from 0.8 to 3.6. The strongest VT earthquake was felt at intensity 1 in La Carlota City (Negros Occidental) and Canlaon City (Negros Oriental).
VT is generated by the rock fracturing process, according to Bornas.
The increase in this activity at Kanlaon strongly indicates progressive rock fracturing beneath the volcano as rising magma or magmatic gas drives a path toward the surface, she added.
On Sunday, volcanic sulfur dioxide (SO2) gas emissions from the summit crater of Kanlaon averaged 2,338 tons, Phivolcs reported.
“These parameters indicate that the blockage of volcanic gas emission (or closed-system degassing) may result in pressurization and swelling of the edifice potentially leading to a moderately explosive eruption,” Bornas said.
She stressed that while they expect a major eruption at Kanlaon, it could take years to happen after a long period of unrest.
Alert level 2 remains in effect at Kanlaon, which means the volcano is in a state of increased unrest. No one is permitted within the 4-kilometer permanent danger zone around the volcano, Bornas reiterated.
