LEGAZPI CITY, Philippines – The ascent of magma is threatening the collapse of the lava dome blocking the crater of Mayon Volcano, signaling a pyroclastic flow if the volcano erupts, the Philippine Institute of Volcanology and Seismology (Phivolcs) warned yesterday.
Bicol-Phivolcs resident volcanologist Ed Laguerta said an aerial survey confirmed that lava flowed from the west side of the 500,000-cubic meter lava dome facing Bonga Gully on Sunday.
Laguerta said the lava flow reached some 400 meters down the slope, 50 meters farther than last week.
“Because fresh lava has found an exit point through that puncture in the lava dome, the possibility of the previously feared big dome collapse is now smaller. But the threat of a strong eruption remains, depending on the pressure that will push the magma out of the volcano,” Laguerta told The STAR.
The sustained faint crater glow, Laguerta added, is an indication that magma ascent to the surface is continuing.
“There is no doubt that the magma is ascending to the upper slope as evidenced by the two lava flows, although both are not yet sustained as they stopped after they rolled down by as far as 350 meters last Oct. 12 and 100 meters last Oct. 19,” Laguerta said.
Phivolcs’ latest monitoring detected at least two volcanic earthquakes with sulfur dioxide emission at 272 tons a day. A faint crater glow was also observed Sunday night.
Laguerta earlier warned disaster officials that a pyroclastic flow is lethal as it travels at 60 kilometers per hour at 600 degrees Celsius.