Legazpi City (Philippine Daily Inquirer/ANN) Bicol City’s Mt. Mayon volcano exhibited at least 15 quakes and one rock-fall the past 24 hours. Together with it was the Mt. Bulusan of the neighboring Sorsogon province also showing signs agitation.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said in its latest bulletin that a moderate emission of white steam shot up 400 meters above Mt. Mayon’s crater was drifting west-southwest and southwest. Glowing of its crater was also observed at Intensity 2 (observable by the naked eye). The results of a ground deformation measurement that was conducted last May 7-11, when compared to another that was done last May 6-10, showed slight increase in the volcano’s structure.

The Alert Level 1 that was declared by Phivolcs last May 11 is currently still in effect, meaning that there may be occasional sudden steam and ash explosions. Citizens are advised not to enter the six-kilometer radius Permanent Danger Zone (PDZ) because of this and possible sudden small explosions. They are also advised to stay away from avoid active steam and river channels as well as perennially identified lahar-prone areas at the southern portions of Mayon especially if the weather fares to be bad.

As for Mt. Bulusan in Sorsogon, though it has appeared to have quieted down, its seismic activities remained unpredectible. Phivolcs’ measurements of seismic activity with their instruments detected 11 volcanic quakes within 24 hours of Saturday. The quakes have lowered down to 4 within 24 hours during the last measurement today (Sunday). This fluctuating trend in volcanic activity was a definite sign that Mt. Bulusan was currently unstable, said Phivolcs resident volcanologist Ed Laguerta.

Laguerta assures that Phivolcs will continue to monitor Mt. Bulusan since it once again emitted ash last Friday and some ground deformation was observed around the volcano’s perimeter. He also advised local disaster councils in Sorsogon to be ready for the likelihood of any possible complex changes.