No major damage has been reported following the 20-minute ash explosion of Mt. Bulusan in Sorsogon on Tuesday, except for light ash falls that blanketed at least 12 villages, the Philippine Institute of Volcanology and Seismology (Phivolcs) said yesterday.
Phivolcs said 46 volcanic earthquakes have been recorded in the area in the past 24 hours since the eruption even as steam and ash continued to pour from its summit.
“Following the ash explosion on Monday morning, the overall activity of Bulusan volcano remained at an abnormal state,” Phivolcs said.
“Steaming activities were moderate but sometimes not observable due to clouds covering the summit crater,” it added.
Phivolcs warned that another eruption could take place at any time, and that local residents should be alert for volcanic mudflows if heavy rains fall on Bulusan’s slopes.
“The high level of seismicity and the most recent ash ejection attest to the restless condition of the volcano,” Phivolcs said.
Delia Tubianosa, resident volcanologist of Phivolcs based at Cabid-an monitoring station in Sorsogon City, however said Bulusan did not show any further abnormal behavior in the past 24-hour observation period.
“We only recorded three volcanic quakes from 6 a.m. to 12 noon yesterday. The steaming is also moderate. Because of this, we cannot yet determine whether Bulusan is leading up to a bigger eruption or not,” Tubianosa said.
Tubianosa downplayed reports that Tuesday’s explosion was the biggest so far for Bulusan. She said there had been more violent explosions in the past but admitted last Tuesday’s was a “forceful ash ejection.”
The 1,559-meter Mt. Bulusan erupted on Tuesday morning with a burst of ash that shot six kilometers above the crater, weeks after Phivolcs lowered the alert status to level 1.
Phivolcs said the communities blanketed by three-millimeter thick ashfalls include barangays Bolos, Caladgao, Cogon, Gulang-Gulang, Gabao, Omagom and Mombon in Irosin town and barangays Puting Sapa, Sangkayon, Buraburan and Bacolod in Juban.
Local officials led by Sorsogon Gov. Sally Lee are taking no chances and ordered the evacuation of thousands of residents living near the foot of the volcano.
Lee said she had also mobilized a task force for a cleanup drive of the main roads and major thoroughfares of the province blanketed by ashfall.
The Department of Social Welfare and Development (DSWD) said they have sent relief goods to Sorsogon, along with 3,000 face masks, particularly the 12 villages affected by ashfall.
DWSD Secretary Esperanza Cabral said 1,000 food packs and 1,000 clothing packs have been sent and preparations have been made in case of a major eruption.
Phivolcs deputy director Bartolome Bautista said last Tuesday’s eruption was “phreatic,” which means it was a steam driven explosion. He said there are no indications of an impending major eruption.
Phivolcs, however, said alert level 1 remains in effect, which means a four-kilometer permanent danger radius around the volcano is still enforced.
Residents living near the river or stream channels are also warned of life-threatening lahar mudflows during heavy rains.
Bulusan is one of the Philippines’ 22 active volcanoes. It is known to have erupted 16 times previously, the last one being in early 2006.
Unlike Mt. Mayon in Albay which has one main vent, Bulusan has one crater and three observable fissures.
In the event of a major eruption, these fissures become conduits for lava and molten rocks. –With Celso Amo, Cet Dematera, AFP