Two Philippine volcanoes are showing signs of activity, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).
In a bulletin issued on Sunday, Mount Mayon in Albay Province registered 15 volcanic quakes and one rock fall in the last 24 hours.
On the same day, Mount Bulusan in Sorsogon Province logged four volcanic earthquakes on Sunday and another 11 on Saturday. The fluctuating volcanic activities are signs that Bulusan remains unstable, according to a volcanologist of the agency.
Phivolcs reported a moderate emission of white steam that shot up 400 meters (1,312 feet) above Mayor’s crater.
With these observations, Phivolcs raised Alert level 1 over the area surrounding Mayon Volcano, which places a six-kilometer (3.7-mile) radius under a permanent danger zone on the area.
The agency, however, said that while no eruption may be imminent, there is a continuous threat from sudden small explosions and rock falls from the upper and middle slopes of Mayon.
Phivolcs advised local disaster councils in Sorsogon to be prepared in case Bulusan shows increased volcanic activities in the coming days. The Alert status in the area surrounding Bulusan is also at level 1, but the permanent danger zone is at a smaller 4-kilometer (2.5-mile) radius.