By Chito Chavez
The Philippine Institute of Volcanology and Seismology (Phivolcs) said a total of seventy-six (76) volcanic earthquakes, most of which corresponded to lava fountaining events were recorded by Mayon Volcano’s seismic monitoring network.
State volcanologists said that there were sporadic and weak lava fountaining, lava flow and degassing from the summit crater of Mayon Volcano in the past 24 hours.
Although the upper slopes were heavily obscured, Phivolcs said the seismic record indicated discrete episodes of lava fountaining that lasted three to 55 minutes.
Throughout the night, lava flows and consequent incandescent rockfalls were observed in the Miisi and Bonga-Buyuan channels.
Effused volumes of incandescent lava flows have advanced to 3.3 kilometers, 4.5 kilometers and 900 meters down the Miisi, Bonga and Basud Gullies, respectively, from the summit crater.
Pyroclastic density currents or PDCs have deposited to the 4.6, 4.5 and 4.2 kilometer reaches of the Miisi, Bonga and Basud Gullies, respectively.
Phivolcs noted that electronic tilt and continuous GPS still record sustained swelling or inflation of the edifice since November and October 2017, consistent with pressurization by magmatic intrusion.
Alert Level 4 remains in effect over Mayon Volcano.
With this state, Phivolcs asked the public to take appropriate actions and not to enter the eight kilometer-radius danger zone.
State volcanologists advised the public to be additionally vigilant against pyroclastic density currents, lahars and sediment-laden stream flows along channels draining the edifice.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft.
Phivolcs has maintained the close monitoring of Mayon Volcano.