Mayon rumblings intensify; over 500 'weak' volcanic quakes detected
The Philippine Institute of Volcanology and Seismology (Phivolcs) detected an increase in the frequency of volcanic earthquakes in Mayon, prompting the agency to issue a new notice of “increased activity” in the restive volcano in Albay on Tuesday afternoon, July 18.
Phivolcs said 573 low-frequency volcanic earthquakes (LFVQs) were recorded in Mayon since July 16.
“Some of these LFVQs were detected by infrasound sensors and were reported to have produced audible rumbling sounds on the evening of July 17 and this morning (July 18). Based on seismic analyses, most of the events originated from a shallow source and are associated with rapid releases of volcanic gases,” it pointed out.
However, Phivolcs said there are no visible changes in the Mayon Volcano’s effusive activity or a significant increase in its overall seismic energy release.
Meanwhile, sulfur dioxide emissions have been increasing since July 12 and peaked at an average of 2,989 tons per day on July 15.
Its emission was measured at 1,945 tons per day on July 18.
The Mayon Volcano ejects massive pyroclastic density currents (PDC) towards the Basud Gully in Sto. Domingo town in Albay province around 5:30 p.m. on July 10, 2023. (Niño Luces/Manila Bulletin)
The Mayon Volcano ejects massive pyroclastic density currents (PDC) towards the Basud Gully in Sto. Domingo town in Albay province around 5:30 p.m. on July 10, 2023. (Niño Luces/Manila Bulletin)
Alert level 3 stays
According to Phivolcs, Mayon Volcano’s seismic and degassing parameters have been undergoing changes that may progress into further volcanic activity. It noted that Mayon remains on alert level 3. Phivolcs advised communities near the restive volcano to maintain increased vigilance against lahars and sediment-laden stream flows along channels draining the volcano edifice, as heavy rainfall could cause channel-confined lahars and sediment-laden stream flows. Since Mayon Volcano’s status was upgraded twice in the past month, first to level 2 on June 5 and then to level 3 on June 8, Phivolcs strongly advised that entry into the six-kilometer permanent danger zone be strictly prohibited. It also warned communities within the seven to eight-kilometer radius from the Mayon crater to brace themselves in case the current pyroclastic density current activity worsens. Furthermore, it warned that ash fall may occur in areas south of Mayon Volcano due to current wind patterns. Phivolcs advised pilots to avoid flying near the volcano’s summit because ash from a sudden eruption can be dangerous to aircraft.