Philippines: Mayon Volcano - Information Bulletin n° 1

The situation

Mayon Volcano was at alert level I on 13 January 2018 due to abnormal activities of the volcano. This was raised to alert level II on 00H30 14 January as more phreatic eruptions occurred. On the evening of 14 January, the Philippine Institute of Volcanology and Seismology (PHILVOLCS) raised Mayon Volcano’s alert level from II to III, signifying that Mayon has increased tendency towards hazardous eruption. PHILVOLCS reports that Mayon is exhibiting relatively high unrest and that magma is at the crater and that hazardous eruptions are possible within weeks or even days. Mayon’s crater was also exhibiting bright crater glow that signifies the growth of a new lava dome and beginnings of lava flow towards the southern slopes.

Mayon Volcano is in Albay province in the Bicol region, around 300 km southeast of the Philippine capital, Manila. According to records, Mayon has erupted 51 times in the last 400 years, with more than 1,350 people having lost their lives. The last fatal eruption happened in 1993 while the last major activity of Mayon was in August – September 2014 when it was also put on alert level III, which displaced more than 55,000 people within an 8-km extended danger zone. No casualties were reported, primarily attributed to the pre-emptive evacuation done by the government.

On the morning of 15 January 2018, two lava collapse events occurred in the volcano, producing rockfall and small-volume pyroclastic density currents. Ash clouds were also produced with ashfalls reported in 29 villages (barangays) in the municipalities of Camalig and Guinobatan in the southwest of the volcano. Furthermore, on 16 January, lava flow and more rockfall events and short pyroclastic flows were also observed.

With the alert level raised, PHILVOLCS recommended that the 6-km permanent danger zone and a 7-km extended danger zone be enforced due to the danger of rockfalls, landslides and sudden explosions or dome collapse that may generate hazardous volcanic flows. Increased vigilance against pyroclastic density currents, lahars and sediment-laden stream flows have been advised, while civil aviation authorities have been instructed to advice pilots against flying near the volcano’s summit due to ash.

As a result of the heightened alert level, precautionary evacuations have been conducted in 25 villages (barangays) in 3 municipalities and 2 cities. As of 15 January, a total of 5,318 families (21,823 people) have been displaced, with 4,134 families (16,877) staying in 18 evacuation centres according to the Department of Social Welfare and Development (DSWD). The final number of displaced families are still unknown as more evacuations are still underway.