Bulusan continues to show abnormal behavior
By Cet Dematera
Bulusan Volcano in Sorsogon continues to display abnormal behaviour although its volcanic earthquakes fluctuated in the last the three days, while its surface and upper slopes remained inflated or bulging, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported recently.
Phivolcs did not detect earthquake on May 18 but recorded 15 shakes on May 23 and 24. But bulging of the volcano’s surface and its upper slopes remained sustained.
April Dominguiano, Phivolcs resident volcanologist at the Cavid-An monitoring station in Sorsogon City, said that the white steam plumes indicate hydrothermal processing inside the volcano.
“All the parameters that we could observe on Bulusan are all within the alert level one or abnormal status, although some of them are fluctuating at times,” Dominguiano told Bicol Mail.
The other abnormal traits of Bulusan include the sustained ground deformation and upper slope inflation, which Dominguiano said indicate that shallow hydrothermal processes are taking place under the volcano.
“We are closely monitoring Bulusan to make sure that any escalation in its abnormal parameters could be immediately disseminated to the authorities and the public,” Dominguiano said.
Entry inside the four-kilometer permanent danger zone (PDZ) remained prohibited as alert level one, or abnormal status was raised over Bulusan on May 12 due to swarm of earthquakes that reached over 150.
Trekking inside the PDZ is also banned when Bulusan is abnormal.
The usually affected towns when Bulusan is abnormal were already alerted for possible evacuation should the volcano’s condition worsen.
Most affected during Bulusan’s ash explosions are Bulusan, Irosin, Juban, Casiguran and Barcelona.
Bulusan last violent eruption was in December 2016 with thick ash columns ejected in its four major vents (craters).