(Eagle News) — The Philippine Institute of Volcanology and Seismology has lowered the alert status of Mt. Pinatubo to “normal.”
PHIVOLCS said this was following “a continued decline in earthquake activity and a return to baseline seismic parameters” in the volcano since July 1.
According to PHIVOLCS, 104 volcanic earthquakes with magnitudes of ML0.8 to ML1.3 were recorded from July 1 to August 11.
This represents an average of two to three events per day and is a significant decrease compared to the 12 to 13 events per day reported from January 28 to June 30.
PHIVOLCS said the strength of the earthquake activity for that period ranged from from ML 0.7 to ML3.2.
According to PHIVOLCS, diffuse CO2 flux from the Pinatubo Crater lake was also measured at 263 tons per day in mid-April 2021, “well within the background range of <1000 tons/day recorded since 2008.”
Data also showed that the ground deformation detected is “likely tectonic, rather than volcanic, in origin.”
“In view of the above, PHIVOLCS-DOST is now lowering the alert status of Pinatubo Volcano from Alert Level 1 to Alert Level 0. This means observational parameters have returned to baseline levels and the volcano has returned to a period of quiescence,” PHIVOLCS said.
PHIVOLCS said the alert level, however, may be increased once again “in the event of a renewed increase in any one or combination of the above monitoring parameters.”
It also cautioned against the entry into the Pinatubo crater area due to “perennial hazards of rockfalls, landslides and expulsions of lethal volcanic CO2.”
PHIVOLCS raised the Pinatubo’s alert level to 1 in March.
