Pinatubo quiets; alert lowered to zero

MANILA, Philippines — Mt. Pinatubo has been placed on Alert Level 0 or normal alert by the Philippine Institute of Volcanology and Seismology.

Phivolcs said this means the volcano has returned to a period of quiescence or no major eruption is seen in the near future.

The agency said there was a return to baseline seismic parameters following continued decline in earthquake activity since July 1.

Phivolcs said only 104 volcanic earthquakes or an average of two to three events per day, with magnitudes of 0.8 to 1.3, were recorded compared to up to 13 events per day from Jan. 28 to June 30.

The agency said carbon dioxide flux from the Pinatubo crater lake, which was measured at 263 tons per day in mid-April, is within the background range of less than 1,000 tons per day since 2008.

Phivolcs said the ground deformation detected from June 2020 to May 2021 shows it could be tectonic in origin rather than volcanic.

It said entry into the Pinatubo crater should still be conducted with caution due to hazards of rock falls, landslides and lethal expulsions of volcanic carbon dioxide.

People living in valleys and active river channels were advised to remain vigilant against sediment-laden streamflows and lahar.

Phivolcs raised Alert Level 1 or low-level unrest over Pinatubo in March after detecting abnormal parameters and persistent seismic activity that may be related to tectonic processes beneath the volcano.