Following Bulusan Volcano’s eruption on Sunday, June 12, the Philippine Institute of Volcanology and Seismology (Phivolcs) has warned against the negative effects of fine ashfall on health of the public.

“Fine ashfall can cause irritation and breathing problems, especially among the vulnerable population – the elderly, children, expectant mothers, and those with respiratory disorders – and can be particularly dangerous when inhaled in copious amounts,” it said.

The Phivolcs noted that ashfall even when thin but having high amounts of sulfur can also irritation.

The affected residents were urged to wear N95 grade facemasks or a wet cloth or towel, it added.

“Motorists are advised to drive with extreme caution as ash can cause poor visibility and, when wet, can make roads slippery.”

Eruption, rumbling sound

In its 4:30 p.m. update, the Phivolcs said Bulusan’s eruption at 3:37 a.m. and lasted for approximately 18 minutes and was recorded as an explosion-type earthquake by seismic and infrasound instruments.

“The explosion was felt at Intensity III by residents of Barangay Añog, Juban, and at Intensity II in Barangay Inlagadian, Casiguran, all within 5-km of the Bulusan summit.”

According to the Phivolcs, rumbling sounds accompanying Bulusan’s eruption were also reported by residents in Sitio Bagong Barrio, Barangay Santa Lourdes, Barcelona, Barangay Inlagadian and Barangay San Juan, Casiguran, Barangay Bentuco, Gubat, and Barangays Añog, Calateo, and Puting Sapa, Juban.

Also, it was reported that there was brief incandescence at the base of the eruption plume in Barangay Inlagadian, Casiguran.

Ashfall

The Phivolcs said multiple active vents at the summit were observed spewing ash and steam by daybreak.

“In the morning, six vents – the major crater called Blackbird, three explosion pits on the summit, and the lateral vents on the northwest and north sides of the summit – were actively degassing short plumes which entrained ash until at least 9 in the morning,” it said.

In addition, the Phivolcs noted that the plumes dispersed into a long veil of ash extending several kilometers to the northwest.

“This period of ‘ashing’ was accompanied by very weak sporadic volcanic tremor. Degassing of steam-laden plumes continues while the Blackbird Crater generates a thin haze of ash upon the upper northwestern slopes.”

Thin ashfalls have been observed on the following barangays and municipalities of Sorsogon Province:

Municipality of Casiguran — Barangays Cogon, Inlagadian, San Juan, Tulay

Municipality of Juban —Barangays Añog, Aroroy, Bacolod, Buraburan, Calateo, Lajong, Mabini, Puting Sapa, Tublijon

Municipality of Magallanes —Barangays Incarizan, Pili, Sta. Elena, Tula-tula

Meanwhile, wind-drifted ash was reported in Sorsogon City and Palanas, Pilar, Sorsogon Province across Sorsogon Bay and as far as Anislag, Daraga, Albay, 50 kilometers northwest of Bulusan.