The institute issued a warning concerning the presence of a possible explosive event within a few weeks or possibly a few days at the most active volcano situated on the southern extremity of Luzon Island. This elevated the level of alert to level three out of a total of five levels in the warning system. "Potential explosive activity within weeks or even days," said the institute’s warning statement.
"The overall monitoring parameters indicate that very slow extrusion of shallow degassed magma is ongoing and is incrementally increasing rate, i.e., an effusive magmatic eruption is taking place," the institute said in a bulletin.
"This means that Mayon is exhibiting magmatic eruption of a summit lava dome, with increased chances of lava flows and hazardous pyroclastic density current affecting the upper to middle slopes of the volcano and potential explosive activity within weeks or even days," it said.
PHIVOLCS has also recommended the evacuation of individuals residing within the 6 km radius danger zone "due to the danger of pyroclastic density current, lava flows, rockfalls, and other volcanic hazards," adding that "increased vigilance against pyroclastic density currents, lahars, and sediment-laden stream-flows along channels draining the edifice is also advised."
According to the institute’s official statement, civil aviation authorities provide should advise pilots to refrain from flying in proximity to the volcano's apex due to the potential peril of airborne ash resulting from any unforeseen eruption.