The Philippine Institute of Volcanology and Seismology (Phivolcs) on 6 July raised the alert level for Bulusan volcano to 1, saying the volcano located in the southeast of Manila "is currently in an abnormal condition."

Bulusan volcano. (Photo: wikipedia.org)

In a bulletin, the institute said it recorded a total of 53 volcanic earthquakes since 3 July, including 43 "low-frequency events that are associated with weak and shallow hydrothermal or magmatic gas activity within the edifice."

The institute further said that ground deformation data from continuous global position system (GPS) measurements also indicate short-term inflation of the edifice since late February.

Phivolcs advised the villagers to stay away from the 4-km radius permanent danger zone (PDZ).

The institute also urged the civil aviation authorities to warn pilots to avoid flying close to the volcano's summit as ash from any sudden phreatic eruption can be hazardous to aircraft.

Bulusan volcano, situated in the province of Sorsogon in the Bicol region, is one of the active volcanoes in the Philippines. The volcano last erupted in January 2018 when it spewed ash about 2.5 km high into the sky above its crater.

Source: VNA