LEGAZPI CITY, Oct. 19 (PNA) -- Mount Bulusan in Sorsogon spewed a kilometer-high ash cloud that lasted for around nine minutes early morning on Wednesday, its second time this week, the Philppine Institute of Volcanolgy and Seismology (Phivolcs) said.
He said volcanologists found 0.5 millimetres traces of ashes that drifted towards villages in Bulusan town.
Eduardo Laguerta, resident volcanologist at the Phivolcs’ observatory in Lignon Hill here, said the phreatic eruption was the second to take place this week (the first was on October 17) and the third eruption this month.
He said the eruptions were normal occurrences since the volcano has been exhibiting some 20 eruptions since May last year.
“What we are closely checking is the presence of fresh magma that could be expelled by the volcano which would indicate that magma is developing beneath the volcano’s vent,” Laguerta said.
State volcanologists are gathering ash samples every time the volcano erupts to determine if there are fresh magma particles in it.
Phivolcs’ seismic monitoring instruments recorded 28 volcanic earthquakes during the past 24-hour period, said Phivolcs’ 8 a.m. bulletin today.
The earthquakes were triggered by rock fracturing due to hydrothermal pressure developing in the volcano’s vent that also generates the phreatic explosion, added the bulletin.
Mt. Bulusan also emitted 176 tonnes of sulfur dioxide which Laguerta said is just a “normal value.”
The volcano’s slopes continue to show signs of “bulging” or inflationary trends since July this year.
Alert Level 1 remains in effect over Bulusan volcano which means it is in a restive state or abnormal condition.
The public are reminded not to enter the designated four-kilometer Permanent Danger Zone due to the possibility of sudden and hazardous phreatic eruptions.
Civil aviation authorities advised pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption could be hazardous to aircrafts.
Residents near river channels, especially on the southwest and northwest sectors of the volcano’s edifice, should be cautious. (PNA) FPV/GVR/MSA/MEC