'Fewer Mayon earthquakes detected, but explosive eruption still possible'


Posted at Dec 26 2009 09:38 AM | Updated as of Dec 30 2009 03:02 AM

MANILA, Philippines - The Philippine Institute of Volcanology and Seismology (Phivolcs) said Saturday a hazardous eruption is still possible despite the decreasing number of volcanic earthquakes being detected from Mayon Volcano.

Phivolcs' 7 a.m. Saturday bulletin said only 406 volcanic earthquakes with 26 rumbling and 2 hissing sounds were detected for the past 24 hours. It said 142 rock fall events were also observed.

The bulletin added that 33 ash explosions were also detected from the volcano.

Ed Laguerta, resident volcanologist in Legazpi City, said that the Mayon Volcano may appear to be calming down, but it's still in a "high level of unrest."

"If we look at the numbers, it would look like the volcano has calmed down, but Mayon Volcano is still in a high level of unrest and an explosive eruption is still possible within days," Laguerta told radio dzMM, adding that Alert Level 4 remains hoisted over the volcano.

Laguerta said despite the lower seismic activity, the volcano's sulfur dioxide emission rate remained high with an average of nearly 9,000 tons per day.

He added that the decreased seismic activity of the volcano may be an indication that magma underneath the near-perfect cone shaped edifice is starting to get clogged.

"If we look at the volcano's history in 1984, the volcano calmed down but after a few days it erupted," Laguerta said.

The Provincial Disaster Coordinating Council of Albay has already evacuated 9,880 families from the 6-kilometer to 8-kilometer danger zones.

The evacuated families are from 32 villages in Camalig, Daraga, Legazpi City, Tabaco City, Malilipot, Sto. Domingo, Ligao City and Guinobatan. With a report from Alex Calda, radio dzMM