By Dominique Gabriel G. Bañaga
During a visit to Bacolod City yesterday morning, Philippine Institute of Volcanology and Seismology (Phivolcs) director and Department of Science and Technology (DOST) Undersecretary Renato Solidum recommended Negros Occidental local government units prepare for the possibility of a Mt. Kanlaon eruption, along with earthquakes from the newly-discovered fault lines on the island.
With the volcano still under an Alert Level 2, the government official said the current state of Mt. Kanlaon is “abnormal.”
Solidum pointed out the ongoing situation, including increased seismic activity and the irregular sulfur dioxide levels, shows there is magmatic activity taking place deep beneath the volcano.
“Although seismic activity has dropped, it’s just normal for the volcano,” Solidum said. “However, because of ground deformation data, we think that there is still pressure below.”
In terms of a possible eruption, Solidum believes conditions make a magmatic eruption unlikely, which is typically explosive in nature, similar to the 1991 eruption of Mt. Pinatubo. However, he said a phreatic eruption, caused by steam-driven explosions, created by water heated by magma, lava, or new volcanic deposits, which have been recorded at Mt. Kanlaon, is just as dangerous and affirmed the public should keep clear of the volcano’s four-kilometer permanent danger zone.
He added, areas around the danger zone should also be prepared for lahar, which consists of mudflow or debris flow.
Meanwhile, with the recent discovery of new fault lines in Negros, Solidum said it is high-time for earthquake-resistant structures.
He explained, buildings should be constructed with hollow blocks that are six-inches thick, and use vertical steel bars with a spaced diameter of 10mm, or 40cm to each other.
With Negros being the home of several century-old houses and churches, Solidum said owners and local officials should think seriously about earthquake retrofitting, similar to what was done to the Manila Cathedral in 2012./DGB, WDJ
