36 volcanic quakes rock Mount Mayon

By Mar S. Arguelles


The Philippine Institute of Volcanology and Seismology (PHIVOLCS) said on Wednesday, Jan. 27 that 36 volcanic quakes rocked Mount Mayon for the past 24-hour period, but its scientist said there is no cause for alarm.


Phivolcs seismic instruments for over a week (Jan.16 to 27) have recorded a total of 88 volcanic earthquakes and several rockfall events.


Dr. Paul Alanis, Phivolcs resident volcanologist, said that the increasing number of tremors are normal occurrences exhibited by the volcano when it is under abnormal condition or Alert Level 1.


Alanis, in aninterview, said the volcanic quakes are not related to magma build-up as these are only surface volcanic movements cause by “hydrothermal” activity inside the volcano’s vent dismissing speculation of an increasing level of unrest.


He explained that hydrothermal activity is an effect when water interacts with rocks inside the vent causing ground movements, “this is similar to the volcanic event that occurred in Mount Bulusan.”


Another factor was the rains that pelted the province for the past weeks, these episodes triggered the hydrothermal activity inside the volcano.


He also clarified that there was no scientific basis to raise the volcano’s alert status to Alert Level 2.


Alanis said Mount Mayon would remain abnormal as the parameters being exhibited include faint crater glow, tremors, gas emission, edifice bulging, and the lava dome.


Asked about how intense is the crater glow exhibited by the volcano, Alanis said “so far the faint crater glow could not be seen by a naked eye without the help of a special camera or telescope.”


He said what they are closely monitoring is strong magnitude earthquake that could possibly dislodge the lava dome at the volcano’s summit “the dome when it breaks can produce pyroclastic blast that could endanger villagers living inside or near the designated 6-km Permanent Danger Zone.”


Phivolcs instrument has observed that Sulfur dioxide emission was measured at 401 tons per day, which was below the normal average 500 tons/day.


Ground deformation data indicate that the edifice is still inflated.


Alert Level 1 (abnormal condition) remains hoisted around the volcano and the public is warned not to enter the 6-km Permanent Danger Zone due to sudden rock falls, landslide at the middle to upper slopes, steam-driven or phreatic explosions.