By JEN BAYLON
Despite its seemingly calm appearance, Kanlaon Volcano remains a potential threat, the Philippine Institute of Volcanology and Seismology (Phivolcs) said, stating the volcano is showing signs of unrest.
“Just because the volcano looks calm doesn’t guarantee that another eruption won’t happen,” Phivolcs resident volcanologist Mari-Andylene Quintia said.
She added that Kanlaon’s continuing activity includes the formation of clogs due to low sulfur dioxide emissions, which is a key indicator of volcanic unrest.
Quintia said volcanic earthquakes suggest magma movement beneath the surface, signaling that Kanlaon is far from dormant.
Phivolcs recorded a total of 18 volcanic quakes on Friday, May 23.
The agency noted a drop in sulfur dioxide emissions to 978 tons on May 22, and even lower at 653 tons on May 20.
Phivolcs also noted a decline in gas emissions at Kanlaon by less than 1,000 tons per day since May 19.
However, Quintia warned this could be a sign that the “volcanic conduit is plugged,” which may result in pressure build-up that may lead to unrest.
Kanlaon remains under Alert Level 3, signaling ongoing magmatic unrest with the potential for sudden explosive eruptions, lava flows, ashfall, and other volcanic hazards.
The volcano had a five-minute minor explosive eruption in the early morning of May 13, emitting voluminous grayish plumes that rose approximately 4.5 kilometers above the vent before drifting southwest.
It also generated incandescent pyroclastic density currents that descended to the southern slopes of the volcano, reaching approximately two kilometers, and produced large ballistic fragments thrown around the crater within a few hundred meters.
Mudflow
Heavy rains in the last few days triggered a mudflow from Kanlaon’s minor eruption, which blocked a major road in Negros Occidental’s La Castellana town on Saturday morning, May 24.
The mudflow overflowed at Tamburong Bridge, causing mud and volcanic debris to block Biak na Bato Bridge and the stretch of the highway at the foot of Kanlaon, leaving thick mud deposits in surrounding areas.
The rapid flows of volcanic debris and water caused significant road blockages, rendering the highway impassable, prompting immediate clearing operations at past noon on Saturday.
According to Biak na Bato village chief Joselito Martinez Jr., the affected portion of the road is approximately 50 meters long.
More than 300 households are temporarily staying in the town’s evacuation centers following the lahar flow.
Meanwhile, the Office of Civil Defense in Western Visayas (OCD-6), in an advisory, said the mudflow has been further aggravated by the accumulation of volcanic ash.
“It has resulted from ash emissions and several minor to moderate eruptions of Kanlaon Volcano since last year,” OCD-6 said in a statement.
OCD-6 advised residents, especially those near the waterways and low-lying areas, to exercise heightened caution and remain vigilant for further flooding or lahar flows.
Negros Trench
Meanwhile, Phivolcs clarified that the recent series of earthquakes felt in Negros Occidental’s Sipalay City is not unusual and is due to tectonic activity along the Negros Trench.
Phivolcs Director Teresito Bacolcol explained that any seismic activity originating from the Negros Trench is usually felt in Sipalay.
He emphasized that the recent quakes are tectonic in nature and are not connected with Kanlaon’s seismic activities.
Bacolcol also assured the public that the earthquakes in southern Negros Occidental are not indicators of any impending disaster.
On Saturday, May 17, a magnitude 5.1 earthquake struck Sipalay, further confirming activity along the Negros Trench./ With reports from PNA / JB, WDJ