BY DOMINIQUE GABRIEL BAÑAGA
BACOLOD City – Kanlaon in Negros Island, one of the most active volcanoes in the country, showed a “slight increase” in seismic activity.
The Philippine Institute of Volcanology and Seismology (Phivolcs) warned nearby residents to refrain from entering the four-kilometer permanent danger zone.
Sudden and hazardous phreatic eruptions may occur without warning, Phivolcs said.
“Kanlaon Volcano’s monitoring network recorded 28 volcanic earthquakes between Feb. 11 and 13,” the institute said in its advisory issued over the weekend.
The tremors ranged from “ML0.7 to ML2.2 and occurred at shallow depths to depths of 10 kilometers across the northern to eastern portions of the edifice.”
Phivolcs also noted sulfur dioxide gas coming out of Kanlaon’s summit crater on Saturday.
“(It) reached an average of 1,130 tonnes/day, the highest value recorded this year, following a trend since June 2020 of emissions higher than background levels of 300 tonnes/day,” the institute said.
Philvocs added: “These parameters could indicate hydrothermal, tectonic or even deep-seated magmatic processes occurring beneath the edifice.”
Pilots were also warned from flying close to the volcano’s summit, as any sudden phreatic eruption can be hazardous to aircraft.
Kanlaon last erupted on March 29, 2016. It lasted for approximately 12 minutes and produced volcanic plume 1,500 meters above the crater./PN
