Phivolcs raises alert level at Mayon Volcano to '1'

June 1, 2013

The alert level at Mayon Volcano was raised to "1" from zero after the Philippine Institute of Volcanology and Seismology (Phivolcs) saw "abnormal behavior" in the form of crater glow and bluish hydrogen sulfide fumes.

Philippine Institute of Volcanology and Seismology head Renato Solidum Jr. said seismologists the crater glow and bluish hydrogen sulfide fumes were observed over the last two evenings.

"Ito ay kadahilanang sa nakalipas na 36-hour period, dalawang gabi namataan namin mahinang pamumula o pagbaga sa tuktok ng bulkan, o crater glow. May bluish hue na hydrogen sulfide ito ... abnormal ang pinapakita ng bulkan (In the last 36-hour period, or last two nights, we noted a crater glow and a bluish hue indicating hydrogen sulfide. The volcano had shown abnormal activity)," Solidum said in an interview on dzBB radio.

"Ang Alert Level 1 para ang publiko ay magingat (We raised the alert level to '1' so the public will take precautions)," he added.

He said raising the alert level should prompt the public to be extra careful in going near the volcano.

Last May 7, a steam-driven eruption occurred at Mayon, killing some foreign tourists and their Filipino guide.

Some weeks later, a Russian climber who defied warnings climbed the volcano but got stuck and injured, and had to be rescued.

Alert level 1

In a bulletin posted on its website, Phivolcs cited "visible but weak and short-lived emission of bluish (hydrogen sulfide) fumes" observed at Mayon, with persistent crater glow of Intensity I (weak).

"The persistence of weak glow may denote heating of the atmosphere above the crater due to a steady emission of magmatic gas," it said.

Sulfur dioxide varied between 55 and 388 tons a day, and for Friday averaged 290 tons a day, remaining below normal levels of 500 tons a day.

It added seismicity has been "markedly low," while recently concluded ground deformation survey by Precise Leveling indicate a slight inflation of the edifice compared to February 2013 survey data.

"In view of the observation of fumes and visible crater glow, despite most monitoring parameters remaining within baseline levels, Phivolcs is raising the alert status of Mayon from Alert Level 0 to Alert Level 1 as a precaution to the public that the volcano is exhibiting abnormal behavior," it said.

Phivolcs also reiterated its warning to the public not to venture near the 6-km radius Permanent Danger Zone.

It said the PDZ "should be a no-entry zone to the public because of the perennial danger of life-threatening rockfalls, avalanches, ash puffs and sudden phreatic or steam-driven eruptions."

Meanwhile, Phivolcs advised residents around the volcano to remain vigilant and to keep abreast of updates on Mayon's condition through local and national officials. — ELR, GMA News

http://www.gmanetwork.com/news/story/310970/news/nation/phivolcs-raises-alert-level-at-mayon-volcano-to-1