SORSOGON CITY – Government volcanologists here have warned of an explosion from cracks that have developed on the lower slopes of Mt. Bulusan in Sorsogon.
Scientists have discovered that at least three fissures were created along the lower slopes of the volcano as a result of strong ash explosions recently.
Ed Laguerta, local resident volcanologist of the Philippine Institute of Volcanology and Seismology (Phivolcs), said steaming activities were also observed on the fissures located at the Casiguran side, Irosin side and at the northern side of Bulusan volcano.
“We also observed that ashes belched out of these fissures during the May 12 ash explosion of Mt. Bulusan,” Laguerta told The STAR.
He explained that continuing volcanic tremors on Bulusan might further weaken these lower vents and possibly threaten communities near these areas in case of a “big bang.”
Laguerta said that if the summit crater will be clogged in the event of a strong explosion, volcanic materials, including lava, might be ejected from these cracks like what happened in the 1920s.
He said they had already reminded barangay officials and residents below the cracked slopes to be on guard.
Delia Tubianosa, a volcanologist based at Phivolcs’ Cabid-An monitoring station here, said that at least 73 volcanic tremors were recorded in the past 24 hours. The figure, though lower than Monday’s 114, was very high compared to the normal five tremors a day for Bulusan.
“These tremors and inflation of Bulusan’s slopes indicate that volcanic materials are moving under the volcano,” Tubianosa said.
Laguerta, on the other hand, said that they are also trying to analyze whether the cracks developed in connection with the caldera that was active within Bulusan volcano some 40,000 years ago. The caldera turned dormant and is now composed of a big portion of agricultural and residential communities of Irosin town, he said.
“But present abnormal indicators are not yet pointing to this worst case scenario,” Laguerta said.
Phivolcs had raised Bulusan’s alert level from 1 to 2 at noon on Sunday after it recorded over 200 volcanic quakes and ground deformation on Saturday. – Cet Dematera