MAYON Update
Posted on April 17, 2007 - Filed Under Mayon News, Mayon Volcano
This is a notice for the lowering of Mayon activity status from Alert Level 2 (evidence of magmatic intrusion that could eventually lead to an eruption) to Alert Level 1 (no hazardous eruption imminent).
After the alert status was lowered to Alert Level 2 last October 3, 2006, Mayon Volcano (13.2576ºN, 123.6856ºE) has consistently manifested the following:
1. The number of volcanic earthquakes recorded daily (1 3 per day) fell within the threshold level for Mayon of 5 volcanic earthquakes per day;
2. Volcanic tremors associated with magma movement within the volcano conduit as well as those related with the extrusion of lava from the active vent, lava collapse and rockfalls became scarce and most of the time no record at all;
3. Ground deformation measurements showed a deflated volcano edifice indicating no fresh supply of magma from below;
4. The sulfur dioxide emission rate measured at 1,600 to 2,650 tonnes per day (t/d) is coherent with the post eruptive gas emission rate for Mayon Volcano; and
5. The observed crater glow was consistent in intensity (can be observed with the naked eye) but does not indicate any re-intensification of volcanic activity.
The above observations suggest that the volcano’s condition is improving and possibly heading towards normalcy. In view thereof, PHIVOLCS is now lowering the alert status of Mayon Volcano from Alert Level 2 to Alert Level 1. This means that hazardous eruption is not likely to occur. The public, however, is reminded that the 7-km Extended Danger Zone (EDZ) at the southeastern flank of the volcano and the 6-km radius Permanent Danger Zone (PDZ) at other areas remain off-limits due to the continuing threat from sudden small explosions, rockfalls from the upper slopes and secondary pyroclastic flows arising from the collapse of newly deposited lavas at the upper and middle slopes. Active river channels and those areas perennially identified as lahar prone in the southeast sector should also be avoided especially during bad weather conditions or when there is heavy and prolonged rainfall.
Scientists: Philippines’ Mayon Volcano Ready to Erupt
Posted on April 12, 2007 - Filed Under Mayon Volcano, Mayon Volcano Articles
MANILA, Philippines — The Mayon volcano appeared ready to blow its top Monday as six explosions sent ash columns up to a half-mile high and led officials to evacuate 50,000 people from an extended danger zone.
The Philippine Institute of Volcanology and Seismology raised the alert to level 4, saying an explosive eruption appeared imminent. Level 5 represents an ongoing eruption.
Officials extended the danger zone to five miles on the volcano’s southern side, from 4.3 miles earlier.
The new area included at least five neighborhoods in Legaspi city, where classes were immediately suspended. Adjacent areas “should prepare for evacuation in the event explosive eruptions intensify,” a volcanology institute advisory said.
“More than 50,000 people will be expected to be evacuated,” said Jukes Nunez, a provincial disaster officer in Albay province. They include people who have ventured back inside the danger zone to tend crops in the fertile volcanic soil.
Army trucks and other government vehicles have been deployed to ferry residents to at least 30 evacuation centers, Nunez added.
Gerry Losentales, a poor 87-year-old farmer, has refused to leave his hut near his small vegetable farm even after the land was partly seared by lava flows a few days ago. He was among dozens of residents ordered to evacuate Monday from Mabinit village below the volcano.
“I survive by tending that farm and I have lived here all my life,” a teary-eyed Losentales said as soldiers helped him board an army truck loaded with villagers to be brought to a temporary school shelter. “I hope the government can help me now.”
Lava began flowing July 14 and has been slowly extending down Mayon’s slopes.
Volcanologist July Sabit said the alert level was raised after six explosions were monitored starting at 7:08 a.m., with ash columns reaching up to 2,625 feet high. “Lava also continues to flow,” he said.
Earlier, volcanologists said they detected 21 low-frequency volcanic earthquakes in the last 24 hours. Renato Solidum Jr., head of the volcanology institute, said the lava flow could continue, or the eruption could shift from quiet to explosive.
Brig. Gen. Arsenio Arugay, head of a task force that will respond to the situation, was given four to 10 hours to mobilize all concerned agencies.
Last week, the government deployed troops to keep sightseers away from the edge of advancing lava. Solidum earlier said the danger could come from collapse of the lava dome or a sudden explosive eruption that could send pyroclastic flows — clouds of superheated gas and ash — racing down the volcano’s slopes.
Mayon is one of the Philippines’ 22 active volcanos. Its most violent eruption, in 1814, killed more than 1,200 people and buried a town in mud. A 1993 eruption killed 79 people.
The Philippines is in the Pacific “Ring of Fire,” where volcanic activity and earthquakes are common.
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