LEGAZPI CITY, Sept. 19 (PNA) -- A team of geodetic engineers from the head office of the Philippine Institute of Volcanology and Seismology will arrive in Albay on Saturday to determine what caused the decrease in the number of rockfalls and earthquakes exhibited by the Mayon Volcano.
A temporary slowdown on the volcano's activities was experienced during the latest 24-hour observation period wherein the Mayon Volcano’s seismic network recorded only 22 volcanic earthquakes, 70 rockfall events and two high-frequency tremors.
In the immediate past recording, there were 142 volcanic earthquakes and 251 rockfalls.
This developed as the Phivolcs allayed fears of lahar flows in the different river channels around the volcano.
Resident Volcanologist Ed Laguerta said the occurrence of lahar flows is a remote possibility due to the absence of new deposits of volcanic materials from the mouth of Mayon, echoing the earlier assurance of fellow volcanologist Alex Baloloy.
If ever, Laguerta said, it would be huge boulders that are now at the upper portion of the volcano, which came from the lava dome.
He added that if there would be heavy rains, there would be mud flows in the channels along Mayon’s slopes like Basud, Masarawag, Mi-isi, Anoling, Bonga and Padang – all at the southeast quadrant of the volcano.
Laguerta said the recorded rainfall on the volcano during the 24-hour period amounted to only 54 millimeters.
He, however, stressed that the Mayon Volcano still poses a threat of eruption and that everybody should always be on alert.
The chief volcanologist said 80 percent of lahar flow is made of hard materials from the volcano while 20 percent is water and these are dangerous.
He said there would be lahar flows if ash or pyroclastic flow.
Laguerta said even just 10 millimeters of rainfall within the vicinity of Mayon will already cause lahar flow, if there would be pyroplastic flow.
Govenor Joey Sarte Salceda reminded residents on the “no man's land” order within the 6-km-radius permanent danger zone and the 7-8-km-radius extended danger zone at the southeast portion of the volcano to ensure zero casualty.(PNA) CTB/FGS/NIM/CBD