MANILA, Philippines — The Philippine Institute of Volcanology and Seismology (Phivolcs) warned the public against venturing into the crater and immediate vicinity of Mt. Pinatubo after it confirmed a phreatic eruption at past noon yesterday.
“Based on visual reports of an eruption plume and seismic, infrasound and satellite detection, Phivolcs confirms that a phreatic eruption occurred at Pinatubo crater between 12:09 p.m. and 12:13 p.m.,” Phivolcs announced.
The agency said the event produced a plume that was detected by the Himawari-8 Satellite and reported by the Tokyo Volcanic Ash Advisory Center.
”The event was also confirmed to have occurred after ordnance disposal activities by the AFP (Armed Forces of the Philippines), which has no relation to the condition of the volcano, on the northern flanks of Pinatubo conducted prior to noon today,” the agency said.
Since there has been ”very low seismic activity” in the past days and low diffuse volcanic carbon dioxide flux measured at Pinatubo Crater Lake as well as high infrasound over seismic energy released by the eruption, Phivolcs said the event was likely driven by “shallow hypothermal processes beneath the edifice.“
“Communities and local government units surrounding Pinatubo are reminded to be always prepared for both earthquake and volcanic hazards and to review, prepare and strengthen their contingency, emergency and other disaster preparedness plans,” it said.
Phivolcs said it continues to strengthen its monitoring of the volcano with ongoing upgrades to the Pinatubo Volcano Network, periodic geochemical surveys of the Pinatubo Crater lake and GPS and satellite analysis of ground deformation.
Alert Level 1 was raised over the volcano in March due to abnormal parameters and persistent seismic activity.
The alert was lowered to zero in August as the volcano returned to normal.
Pinatubo’s eruption in June 1991 was considered the second largest volcanic eruption of the 20th century. Hundreds of people died and thousands were displaced.