The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that 63 volcanic earthquakes were detected at Mount Bulusan on Monday.
In its 24-hour report, PHIVOLCS noted that the volcano emitted 94 tonnes of sulfur dioxide and produced an ash cloud that rose 70 meters above the summit.
It also stated that a general deflation was observed in the southern sector of the volcano.
This day marked the 15th day since the alert status at Bulusan was raised from 0 to 1 last March 22.
Apart from Bulusan, Taal Volcano in Batangas, which is also in Alert Level 1, exhibited heightened volcanic activity through the same period.
In footage released on their social media platforms, a weak steam-driven eruption was captured at the main crater of the volcano.