PHIVOLCS lowers alert level on Bulusan Volcano to zero

Activities of Bicol region's Mount Bulusan have declined to baseline levels, prompting the Philippine Institute of Volcanology and Seismology to lower the volcano's Alert Level 1 status (abnormal) to Alert Level 0 (normal).

Alert level 1 sa bulkang Bulusan, inalis na ng PHIVOLCS. #SuperBalitaSaHapon

— DZBB Super Radyo (@dzbb) January 25, 2020

Super Radyo dzBB reported Saturday that PHIVOLCS' lowering of the Bulusan alert status was based on the general decline in monitoring parameters, including volcanic quakes, ground deformation, gas emission, and visual observation of the summit.

PIA file photo

In its volcano bulletin on Saturday, PHIVOLCS said, the frequency of volcanic earthquakes has declined to baseline levels (0-2 earthquakes/day) since May 17, 2019, indicating a decline in rock fracturing associated with hydrothermal activity.

PHIVOLCS also said that the overall ground deformation data indicate that there is no pressurization from subsurface magma.

Moreover, it said, "sulfur dioxide (SO2) emission has remained below detection levels since 2018," adding that visual observation indicates that "degassing activity from the active vents has been characterized by weak emission of steam-laden plumes consistent with diminished hydrothermal activity."

But PHIVOLCS reminded the local government units and the public that entry into the 4-kilometer radius Permanent Danger Zone (PDZ), particularly near the vents on the south-southeastern slopes, should be avoided due to the possibility of sudden and hazardous steam-driven or phreatic eruption, rockfall, and landslide. —LBG, GMA News