Mayon Displays Increasing Unrest

By Gil Francis G. Arevalo, Ephraim Aguilar (Inquirer, Associated Press)
Last updated 04:13pm (Mla time) 07/16/2006

LEGAZPI CITY--(UPDATE) During the past 24-hour observation period, the Philippine Institute of Volcanology and Seismology (Phivolcs) on Sunday noted a significant increase in the bulge of advancing lava at Mt. Mayon, causing lava flows to roll down to a distance of about 800 meters from the summit.

The Phivolcs said it was a clear indication of the volcano's increasing unrest.

According to Eduardo Laguerta, senior science research specialist and resident volcanologist of the Phivolcs here, the increase in the lava's extrusion rate is a sign that a greater pressure inside the volcano is at work at an increasing momentum.

Only one minor explosion occurred at 2:47 p.m. on Saturday.

The increase, in the lava extrusion rate was also accompanied by an increase in sulfur dioxide emissions--from the previous 1,251 tons per day to about 2,221 tons per day--measured Saturday morning, the Phivolcs said on Sunday.

The latest Phivolcs bulletin said that at this stage, except for ashfalls, the major hazards of rockfalls, lava flow, and small rock avalanches all occurred within the six-kilometer-radius Permanent Danger Zone (PDZ), which according to the Office of Civil Defense here, covers 5 municipalities and 10 villages with a population of 3,004 families or 15,825 persons.

Laguerta said the Phivolcs was keeping close watch on the volcano's southeast quadrant, which is the highly critical area as it is the direction where lava and other volcanic emissions go, covering areas here and in the towns of Sto. Domingo and Daraga.

Laguerta said there is a big possibility of raising the alert level near Mt. Mayon to four on a five-level alert scale if tremor episodes related to large rock masses detached from the lava flow will continue within the next few days.

He said the latest volcanic activities are indicators of a high probability that there would be a major eruption.

On the streets of this city, about 340 kilometers (210 miles) southeast of Manila, residents watched boulders and other debris cascading from the crater, raising brownish-gray clouds of dust.

Mayon's most violent eruption, in 1814, killed more than 1,200 people and buried a town in mud. A 1993 eruption killed 79.

An eruption warning system is already in place for the quick evacuation of nearby communities, and radio stations have been told to broadcast emergency calls, said Jukes Nunez, an operations officer with the provincial disaster officer.

The Philippines is in the Pacific "Ring of Fire," where volcanic activity and earthquakes are common.

In 1991, Mount Pinatubo exploded in the northern Philippines in one of the world's biggest volcanic eruptions of the 20th century, killing about 800 people.

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