NEGROS OCCIDENTAL, Philippines – The Philippine Institute of Volcanology and Seismology (Phivolcs) has downgraded the alert status of Mount Kanlaon in Negros Island to Alert Level 1 from Alert Level 2.
In an advisory on Friday, January 11, Phivolcs said it lowered the alert status of the active volcano due to the the decline in its overall activity which indicated “no magmatic eruption is foreseen in the immediate future.”
Alert Level 1 means it is in a state of unrest probably driven by hydrothermal processes that could generate steam-driven or phreatic eruptions.
Phivolcs explained that the seismic activities in 2018 were “generally declining to low levels (average of 4 earthquakes/day) but presently remains above baseline levels of 0 to 2 volcanic earthquake per day.
“Much of the seismicity emanated from shallow sources within and beneath the volcanic edifice,” it added.
Phivolcs also said that recent data from continuous GPS measurements showed inflation of the edifice but at a significantly slower rate, which is more likely due to the pressurization from a shallow hydrothermal system.
Based on the visual observation of the summit, the steam it emitted since December 2017 has been “weak to moderate, consistent with a decline in hydrothermal activity,” the agency said.
In lieu of its observations, Phivolcs said it is lowering the status of the volcano, meaning that observational parameters have returned to low levels and no magmatic eruption is foreseen in the immediate future.
However, if there’s an increase in any monitoring parameters, the alert status may be raised again to Alert Level 2, or in a moderate level of unrest, the agency said.
Phivolcs still reminded the public to avoid entering the 4-kilometer radius of the Permanent Danger Zone due to perennial hazards of rockfalls, avalanches, sudden outgassing and steam-driven or phreatic eruption at the summit area.
It said it is closely monitoring Kanlaon’s condition.
Mount Kanlaon, which straddles the provinces of Negros Occidental and Negros Oriental, is the highest point in the Visayas at 2,465 meters (8,087 feet) above sea level. – Rappler.com