LEGAZPI CITY – Almost two years after its major eruption, Mayon Volcano spewed ash again yesterday morning reaching about 200 meters above the crater before drifting east-northeast, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
Ed Laguerta, Phivolcs resident volcanologist, said the ash-ejection was recorded by seismic sensors around the volcano as an explosion-type earthquake, which lasted for one minute.
Laguerta said thick clouds covering the volcano’s summit at that time hindered visual observation of the phreatic explosion, which occurred at 9:12 a.m. yesterday.
“Seismic activity during the past weeks had slightly increased as well as crater glow which had slightly intensified,” observed Laguerta before the ash puff.
Precise leveling surveys, which help determine whether the volcano is inflated, conducted from May 10 to 22 this year – compared to the one taken last Feb. 17 to March 2 this year – showed an inflation of the volcanic edifice.
Laguerta offered two explanations for the ash explosion.
“The above observations show that Mayon Volcano is undergoing an episode of increased activity probably related to magma movement towards the crater or a post eruptive behavior of the volcano,” Laguerta told The STAR during an interview.
The resident volcanologist added that although no major eruption was imminent, steam and ash explosions may occur in the following days.
As a result, Albay Gov. Joey Salceda, chair of the Provincial Disaster Coordinating Council (PDCC), has ordered Cedric Daep, head of the Albay Provincial Safety and Emergency Management Office (APSEMO), to restrict any form of human activity, especially by mountain climbers, orchids collectors and farmers on the six kilometer danger zone due to the risk of super-heated gas which accompanies any phreatic explosion down the slope of the volcano.
“The PDCC is now on 24-hour close watch as disaster-avoidance precautionary measure,” Salceda said.
Phivolcs has reiterated the current advisory to prevent the public from venturing inside the seven-kilometer extended danger zone (EDZ) at the southeastern flank of the volcano as well as the six-kilometer permanent danger zone due to the continuing threat from sudden small explosions and rock falls from the upper slopes.
Active river channels and those areas always identified as lahar-prone around the volcano should be avoided when there is heavy and prolonged rainfall.
Mayor Volcano has been under alert level 1 since 2007. – Helen Flores