LEGAZPI City , Philippines - Mt. Bulusan in Sorsogon spewed ash up to 1,000 meters above the crater rim yesterday afternoon, shortly after some 3,000 villagers had been sent back to their homes, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
Crispulo Deolata, Phivolcs’ resident volcanologist in Sorsogon, said the renewed explosion covered parts of Irosin, Juban and Casiguran towns with ash.
Deolata said they still had to measure how thick was yesterday’s ashfall, which occurred hour after Casiguran and Juban officials allowed the return of residents who had fled their homes when Bulusan began spewing ash last Nov. 6.
Raffy Alejandro, Bicol director of the Office of Civil Defense, said they might again call for an emergency meeting to discuss contingency measures if Bulusan rupts.
Cloudy skies over Bulusan have given scientists a hard time observing the volcano, prompting them to adopt additional parameters to monitor its restiveness.
The cloudiness started three days ago after the volcano spewed steam and ash.
Deolata said that aside from visual observation and volcanic earthquake recording, their teams also installed yesterday additional tiltmeters to detect any ground deformation, and flyspec to determine the volume of its sulfur dioxide emission.
“With these additional monitoring schemes, we will have a more detailed basis to determine whether Bulusan’s present alert level 1 is escalating further or not,” Deolata said.
In its latest bulletin, Phivolcs said at least eight volcanic earthquakes were recorded in the past 24 hours.
“The summit of the volcano was most of the time obscured by thick clouds. However, during times of good visibility, weak to moderate emission of white steam was observed,” the agency said.
It said though that the ash explosions on Nov. 6 and 8 were typical of Bulusan during its restive period, and that it “expects more explosions to occur in view of the volcano’s recent reactivation.”
Villagers were advised to stay out of the four-kilometer permanent danger zone from the two active craters of Bulusan, particularly those in the northwest and southeast areas. – With Helen Flores, Jaime Laude and Celso Amo