Thirty-four volcanic earthquakes and 144 rockfall events were observed at the Mayon Volcano in Albay province over the past 24 hours, according to the Philippine Institute of Volcanology and Seismology (Phivolcs) on Thursday, September 28.
In its latest bulletin, Phivolcs said the 34 volcanic quakes, including one tremor that lasted for one minute.
The state seismologist said the Mayon Volcano's lava continued to advance its length, with 3.4 kilometers (km) in southeastern Bonga gully, 2.8 km in south Mi-si gully, and 1.1 km in eastern Basud gully.
Phivolcs released a video of the "renewed slow effusion of lava" coming from Mayon summit crater that occurred at around 8:49 PM on Wednesday.
Alongside, the Mayon emitted one pyroclastic density current (PDC), and 875 tonnes of sulfur dioxide on Wednesday.
"Rockfalls and PDCs generated by collapses of the lava flow margins as well as of the summit dome deposited debris still within four (4) kilometers of the crater," the state seismologist said.
Since the third week of September, Phivolcs said the northwestern middle slope of Mayon showed slight deflation.
The Mayon Volcano is still under Alert Level 3 due to its relatively high level of unrest.
The state seismologist first raised Alert Level 3 over Mount Mayon Volcano in June 8 this year.
"It is therefore recommended that the 6-km radius Permanent Danger Zone (PDZ) remain evacuated due to the danger of PDCs, lava flows, rockfalls, and other volcanic hazards. Increased vigilance against PDCs, lahars, and sediment-laden streamflows along channels draining the edifice is also advised," said.