Mayon, September 1984, prior to eruption.
[Updated below]
Approximately 50,000 people have been evacuated in the area surrounding Mayon Volcano in the Philippines, in anticipation of what authorities believe to be an imminent eruption of the iconic volcano.
Known as the world’s most perfectly formed, symmetrical cone, the 460-meter (8,071-feet) Mayon lies in the Pacific “Ring of Fire” and is the most active of the Philippine’s 22 active volcanoes. In the past 400 years, the 460-meter (8,071-feet) volcano has erupted more than 49 times, most recently in 2006.
The latest episode of seismic rumblings began last June, suggesting movement of magma beneath the volcano at shallow depths. By December 18, scientists monitoring the situation recorded nearly 250 volcanic quakes and tremors within a 24-hour period, including 50 explosive events that sent ash and gases streaming up to 2,000 meters skyward and lava flowing 3 km down the southeastern slope of the mountain. By December 20, lava flows extended 5 km from the crater, and sulfur dioxide emissions had doubled.
Mayon erupting, Sept. 23, 1984
While locals are being evacuated, the prospect of an eruption may cause a greater than usual influx of tourists; however, army troops and police are enforcing a no-go zone that now extends 7-8 km from the crater.
In an effort to meet the government’s zero-casualty goal, health officials are bracing for potential outbreaks of illness due to overcrowding at the evacuation centers. Not forgotten are the psychological effects evacuees are likely to suffer, particularly as holidays approach. Volunteers from the Health and Social Welfare departments are preparing to help those showing signs of boredom, discomfort or unusual stress due to the imminent eruption and/or being away from their homes and livelihoods for what could be an indefinite period of time.
Updates regarding activity at Mayon are available at the Philippine Institute of Volcanology and Seismology.
UPDATE: 7:00 AM (local); Dec. 21
[A]ctivity escalated during the past 24-hour observation period. Seismic activity dramatically increased in number and size. A total of 1,942 volcanic earthquakes was detected by the seismic network… Harmonic tremors were also continuously recorded.
Sulfur Dioxide (SO2) emission rate remained very high at 6,089 tonnes per day (t/d)… Intensified crater glow and rolling down of incandescent lava fragments from the crater was also persistent. Red hot lava also continuously flowed down along the Bonga-Buyuan, Miisi and Lidong gullies. Lava fountains rising approximately 200 meters above the crater were observed at 2007H, 2008H and 2018H. The lava front has now reached about 5 kilometers downslope from the summit along the Bonga-Buyuan gullies.
