MANILA (UPDATE) — The Philippine Institute of Volcanology and Seismology said Friday it recorded 199 rockfall events in Mayon Volcano in the past 24 hours.
According to Phivolcs director Teresito Bacolcol, the rockfall events more than doubled from the 98 it detected between June 7 and 8.
State seismologists also recorded 6 pyroclastic density current events, which lasted for 4 to 5 minutes.
"This would imply that there's a continuous supply of magma to the surface, dislodging old and new portions of the lava dome," Bacolcol told ANC's "Headstart".
A crater glow was also observed over Mayon Volcano on Thursday night, which meant "superheated gas [was] coming out of the crater which produced this glow," he added.
Phivolcs said that while Mayon Volcano is already ripe for another eruption this year, seismologists hoped the imminent eruption would change its course.
"The difference right now is that we don't see high amount of sulfur dioxide so we are actually hoping for a 2014 scenario, which is just rockfall events followed by short lava flow and then it stopped. Hopefully it will not go the way of the 2018 activity," Bacolcol said.
"Mt. Mayon is being replenished. Mayon Volcano is actually, the earliest would be 3 years after the last eruption and the latest would be 10 years after the last eruption. The last time it erupted was 2018 and it's been 5 years now. So, again we're on the range," he added.
'COINCIDENCE 3 VOLCANOES BECAME ACTIVE'
Phivolcs appealed for calm as 3 volcanoes simultaneously showed signs of increased activity.
Aside from Mayon, Taal and Mt. Kanlaon are both under Alert Level 1.
But Phivolcs said the scenario is not out of the ordinary.
The public though is still advised to remain vigilant, and heed calls for evacuation.
"We have 24 active volcanoes. There's always this possibility that 1 or 2 volcanoes would be restive and would show some activity simultaneously. So, this is not surprising," Bacolcol said.
In a separate briefing, the official said the volcanoes' activities were "independent of each other." This was also not the reason for the recent earthquakes felt in other parts of the country.
"Wala po iyan (connection). Again, iyong bulkan galing po sa magma, iyong mga lindol po natin…may dalawang klaseng lindol tayo – may volcanic earthquake at saka tectonic earthquake," said Bacolcol.
(That is not connected. The volcanic earthquakes are caused by magma. We have two kinds of earthquakes – the volcanic and the tectonic earthquakes.)
"So, kapag tumataas iyong magma natin ay nagkakaroon tayo ng mga volcanic earthquakes pero iyong mga volcanic earthquakes na ito can only be felt doon sa vicinity ng bulkan," he said.
(So if the magma increases, we will have volcanic earthquakes but this can only be felt in the volcano's vicinity.)
Tectonic earthquakes, meanwhile, are produced by sudden movement along faults and plate boundaries. The Philippines has 175 active fault segments capable of generating earthquakes, the Phivolcs chief said.