The Philippine Institute of Volcanology and Seismology yesterday raised the alert level status of Mayon Volcano in Albay from 0 to 1 as the restive volcano exhibited “abnormal” activities in recent weeks.
Based on the monitoring of Mayon’s activities, Phivolcs noted that sulfur dioxide emission has consistently increased beyond the baseline level of 500 tons per day, exceeding 1,000 tons per day in some days since July.
Sulfur dioxide emission tends to increase through time as magma degasses with increasing rates as it moves up from great depths beneath the volcano, Phivolcs explained.
Likewise, ground deformation has become more evident with the “continuous inflationary trend since July.”
“Results of precise leveling and electronic distance surveys on the last week of August indicate inflation of the edifice, possibly due to magma movement at depth,” Phivolcs said.
From August 3 to 6, 146 earthquakes were recorded, mostly located on the southeast side or 10 kilometers away from the volcano.
“This earthquake swarm likely emanated from rock-fracturing processes that may or may not be associated with magmatic activity. However, seismicity has remained below baseline in the weeks succeeding the swarm,” it explained.
Phivolcs also observed that four of the 14 monitored water wells located on the southeastern side of Mayon are experiencing decrease in water discharge, while one well has dried-up.
Steaming activity from the crater ranging from weak to moderate was also seen by Phivolcs, but no crater glow has been observed so far.
Due to these observations, Phivolcs raised the alert level status of Mayon to 1, which means that the volcano is at an abnormal condition and has entered a period of unrest.
Phivolcs warned the public from entering the six-kilometer permanent danger zone due to perennial hazards of rock falls, avalanches, ash puffs, and sudden steam-driven or phreatic eruption at the summit area. (Ellalyn B. de Vera)