Restive Mayon Volcano has recorded an increase in sulfur dioxide emission but this is no cause for alarm, according to the head of the Philippine Institute of Volcanology and Seismology (Phivolcs).

In the 24-hour observation period of Phivolcs on Mayon Volcano released at 8 a.m. Sunday, the volcano in Legaspi, Albay had 752 tons per day sulfur dioxide emission — more than double of its 362 tons/day emission on August 21.

Mt. Mayon in August 20 and 19 recorded just 248 tons/day and 210 tons/day sulfur dioxide emission, respectively.

“We can’t say it is worsening (condition of Mt. Mayon). The increase in the sulfur dioxide is above normal but not significant,” Phivolcs Director Dr. Renato Solidum said.

Solidum said they consider 500 tons and below sulfur dioxide emission as “normal” for volcanoes.

Thus, the evaluation of Mt. Mayon is still at Alert Level 2 status (moderate unrest), he said. Alert Level 2 means “a state of unrest which could lead to ash explosions or eventually to hazardous magmatic
eruption.”

On the other hand, Mt. Mayon also recorded two volcanic earthquakes Sunday. Phivolcs had recorded 57 volcanic earthquakes from the volcano from August 10 to 16.

Mt. Mayon’s crater glow was at Intensity II and its steaming activity still remains at moderate levels.

As for ground deformation, Phivolcs said their August 14-15 2009 precise leveling survey results for the Lidong Leveling Line showed that “there is one millimeter deflation relative to July 2009 survey but still inflated by 4 millimeters compared to October 2007 baseline data.”

“No change relative to June 2009 survey but still inflated by eight millimeters compared to February 2008 baseline data,” Phivolcs said of the Buang Leveling Line.

Mt. Mayon was placed under Alert Level 2 last July 10 because of the increase in its activities since June 2009. The volcano, known for its near-perfect cone shape, was on Alert level 1 (low level unrest) from October 2006 to June 2009.

Phivolcs strongly recommends that the six-kilometer radius Permanent Danger Zone around the volcano and the seven-km Extended Danger Zone on the southeast flank of the volcano remain off-limits due to the threat from sudden explosions and rock fall from the upper slopes.

“Active river channels and those areas perennially identified as lahar-prone in the southeast sector should also be avoided especially during bad weather conditions or when there is heavy and prolonged rainfall,” Phivolcs warned.