LEGAZPI CITY, Albay – The Philippine Institute of Volcanology and Seismology (Phivolcs) on Thursday, March 16, reminded the people that danger from the majestic Mayon Volcano remains despite the lowering of the alert status from two to one.
"The lowering of the alert status should not be interpreted that unrest has completely ceased,” Phivolcs said.
In the event of a renewed increase in any one or combination of the monitoring parameters, the alert status may step up once again to Alert Level 2. On the other hand, if there is a noticeable return to baseline levels of ground deformation and sustained low levels of other monitoring parameters, then the alert status may further step down, it added.
The public was reminded to avoid entry into the six-kilometer Permanent Danger Zone or PDZ due to perennial hazards of rockfall, avalanche, ash puff, and sudden steam-driven or phreatic eruption at the summit area.
“Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be hazardous to aircraft. Furthermore, people living in valleys and active river channels are cautioned to remain vigilant against sediment-laden streamflows and lahars in the event of prolonged and heavy rainfall brought about by the advent of the rainy season,” Phivolcs said.
“Phivolcs-DOST is closely monitoring Mayon Volcano’s activity and any new development will be immediately communicated to all concerned," Phivolcs added.
Phivolcs lowered the alert status of Mayon from 2 to 1 on Thursday morning.
It said that Mayon has exhibited a steady decline in its monitored parameters, prompting them to downgrade the alert level from two or moderate level of unrest to Alert Level 1 or low level of unrest.
Phivolcs added that volcanic earthquakes recorded by the Mayon Volcano Network (MVN) have declined to a daily average of zero to one event per day since the first week of December 2022.
"Most of these occurred at depths of 6-10 kilometers beneath the eastern flanks and are attributed to rock fracturing processes within the volcano. In addition, rockfall from Mayon’s summit dome occurred during periods of intense rainfall over the summit area, rather than from extrusion of new dome lava at the crater," Phivolcs said.