Lava Dome Developing in Mt. Mayon’s Summit

LEGAZPI CITY, Oct. 27  - The Philippine Institute of Volcanology and Seismology (Phivolcs) is closely monitoring Mt. Mayon after a lava dome was seen developing at the volcano's crater on Tuesday.

Phivolcs scientists said magmatic materials might be intruding at the volcano's crater vent that led to the building of a lava dome at Mt. Mayon's crater rim.

The development of a lava dome is a sign that magma is pushing its way to the volcano's summit and might lead to a major eruption.

Dr. Ed Laguerta, Phivolcs resident volcanologist, said the observation is not yet absolute as the agency had to verify further whether a lava dome is indeed developing.

He said that the agency has to conduct further aerial survey on top of the volcano's summit to determine completely whether a new lava dome is developing or it is a "crypto dome" where what is seen at the crater rim are remnants of the 2006 eruption.

Laguerta said, "we have to see that there is a mound of lava developing, since it may be possible that magma may just be pushing old rocks upward and heating them, thus creating a crater glow at night."

The Phivolcs said the volcano continues to exhibit heightened abnormalities manifested by fluctuating sulfur dioxide gas emission levels, high and low frequency quakes, crater glow, ground deformation and ash puffings are significant signs that an eruption may take place any time.

Phivolcs scientists noted Sulfur Dioxide (SO2) gas disgorged by the volcano for the past 24 hours went down significantly at 270 tons on Monday.

The agency seismic instruments detected only 30 high and low frequency volcanic earthquakes, bringing to a total of 39 quakes recorded this week, signifying that magma intrusion is developing in the volcano's crater vent.

Laguerta said the agency seismic networks have recorded about over a hundred earthquakes that rocked the volcano this October.

Precise Leveling result indicates the volcano edifice remains inflated at 6.0 mm swelling at the Buang lines while Lidong lines posted a 1.0-mm inflation.

The volcano crater glow remained at intensity level II, while steam emission was at a moderate level.

This significant volcanic abnormalities prompted disaster authorities to strictly enforce the "no entry" rule in designated danger zone areas surrounding the volcano.

Alert level 2 remains hoisted over Mayon Volcano. Phivolcs strongly recommend that the 6-km Permanent Danger Zone including the 7-km extended danger zones should be off limits to any human activity due to threat from sudden explosions and rockfalls from the upper slopes of the volcano. (PNA)