The Philippine Institute of Volcanology and Seismology (Phivolcs) on Saturday advised residents inside the 7 to 8-kilometer extended danger zone of Mayon Volcano to prepare for possible evacuation.

Mayon Volcano Observatory resident volcanologist Dr. Paul Alanis said pyroclastic density current (PDC) was monitored at the Basud Gully of the volcano, which faces the south and south east quadrants of the volcano.

The said quadrants covers the area of Legazpi City and Daraga, and Santo Domingo in Albay.

“Nagbigay lang po kami ng advise, notice na may ano ngano dumadami 'yung earthquake tsaka nagkaroon ng mga PDC na umabot ng four kilometers ang haba so binigyan lang namin ng notice yung mga nasa seven and eight dun sa South East na mag-ready na mag-evacuate,” Alanis said.

As of 6 p.m. Saturday, Phivolcs recorded 256 rockfall events, one PDC, and two volcanic quakes in Mayon.

This is lower compared to the 65 volcanic earthquakes and 17 dome-collapse pyroclastic density current events recorded on Friday.

The volcanic quakes recorded according to Alanis most likely came from the rockfall events.

Alanis said Saturday’s monitoring showed a decrease in the activity of the volcano compared to the previous day.

“Kahapon po tumaas, ngayon bumaba na naman,” he said. - report from Jose Carretero, ABS-CBN News