THE Philippine Institute of Volcanology and Seismology (Phivolcs) is strictly monitoring Mt. Pinatubo in Zambales after it recorded a “weak explosion” at the volcano’s crater last Tuesday.
Phivolcs said a phreatic or steam-driven explosion was observed at the Pinatubo crater.
“Based on visual reports of an eruption plume and seismic, infrasound and satellite detection, DOST-PHIVOLCS confirms that a phreatic eruption occurred at Pinatubo crater between 12:09 and 12:13 p.m.,” Phivolcs, in a social media post at 6 p.m. on Tuesday, said.
According to the state agency, they are determining the source of the explosion.
“Considering that there has been very low seismic activity in the volcano in the past days and low diffuse volcanic CO2 flux measured at Pinatubo Crater Lake and high infrasound over seismic energy released by the eruption, the event was likely driven by shallow hydrothermal processes beneath the edifice,” Phivolcs said.
The eruption “produced a plume, which was detected by the Himawari-8 satellite, and reported to Phivolcs by Japan’s Tokyo Volcanic Ash Advisory Center.
“So far, there has been no reports of ashfall from communities of Zambales over which the eruption plume dispersed,” Phivolcs said.
The agency confirmed that the weak explosion occurred after the Armed Forces of the Philippines conducted ordnance disposal activities on the northern flanks of Mt. Pinatubo on Tuesday morning, but said the eruption “has no relation to the condition of the volcano.”
Phivolcs reiterated its appeal to the public to stay away from the vicinity of Mt. Pinatubo.
“So far ay wala pa tayong itinataas na alert level. Ang binabantayan lang po ay walang dapat makapunta sa tuktok ng bulkan,” Phivolcs director Undersecretary Renato Solidum said.
Phivolcs reminded local government units and residents of areas surrounding the volcano to always be “prepared for both earthquake and volcanic hazards.”
Mt. Pinatubo has been under alert level 0 since August 12. It last erupted in June 1991, which according to the US Geological Survey was one of the largest volcanic eruptions that killed 800 people.