Kanlaon Volcano calm, but lahar risk looms

Roads in La Castellana, Negros Occidental are rendered impassable on June 5, 2024 as rains spawned widespread lahar flow in the aftermath of the eruption of Kanlaon Volcano. (Photos courtesy of Mt. Kanlaon Natural Park/via Tara Yap)

Kanlaon Volcano in Negros Island has stayed quiet for the past 24 hours, but concerns about lahars remain, leading to the issuance of a lahar advisory.

Based on the volcano bulletin released by the Philippine Institute of Volcanology and Seismology (Phivolcs) at 8 a.m. on Thursday, June 6, Kanlaon experienced 27 volcanic earthquakes, a decrease from the 53 quakes the previous day.

Sulfur dioxide emissions, which were measured at 3,464 tons on June 5, also decreased from 4,133 tons following the eruption.

However, Kanlaon Volcano continues to emit gas, indicated by volcanic plumes reaching 1,500 above its summit crater.

Phivolcs said there has been no new phreatic eruption at Kanlaon Volcano following its “explosive eruption” on June 3.

It said the current observation of volcanic plumes is the result of sulfur dioxide emissions from Kanlaon's degassing activity.

Lahar risk

Despite the volcano's current status, a lahar advisory was issued in response to the heavy rainfall forecast until Friday, June 7.

Phivolcs issued a lahar advisory at 11 p.m. on Wednesday, June 5, citing the ongoing threat of lahars downstream of the active Kanlaon Volcano in Negros Island.

Based on the advisory, heavy rainfall forecasts for June 6 and 7, ranging from 100 to 200 millimeters, are expected to affect Negros Island, which increases the risk of lahars in downstream communities and rivers draining into the southern slopes of Kanlaon.

Phivolcs said the lahars on Wednesday afternoon, which were triggered by heavy rainfall, have deposited mud and debris in several waterways, causing road closures and posing threats to communities along the middle and lower slopes. 

The event has affected Tamburong Creek, flowing through Biak-na-bato and Calapnagan, La Castellana; Intiguiwan River in Guinpanaan and upstream Baji-Baji Falls in Cabacungan, La Castellana; Padudusan Falls, Masulog, Canlaon City; and the Binalbagan River, which drains the southern flank of Kanlaon Volcano.

Phivolcs advised these communities and local governments to be more vigilant and prepared in case lahar flows hit again.

It urged continuous monitoring of weather conditions and preemptive response measures to ensure safety from potential lahars.

READ: https://mb.com.ph/2024/6/6/lahar-warning-raised-in-kanlaon-volcano-amid-heavy-rains