Overview of the situation
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. 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. As of 19 February, up to 90,000 people in six municipalities and two cities of Albay province are affected, with 62,000 people currently in 57 evacuation centres. Lack of drinking water, sanitation facilities, and hygiene and dignity kits have been noted in areas where evacuees are staying.
As of 19 February 2018, a Level 4 alert remains raised over Mayon Volcano. The government has deployed teams to conduct health assessments, while NGOs are working in evacuation centers to provide psychosocial activities for children. Furthermore, the Department of Agriculture has provided farm supplies and materials to 10,500 affected farmers.
I. SITUATION OVERVIEW
A. Chronological of Events and Eruption Notifications from 13 January to 27 February 2018 (TAB A)
B. Current Situation
28 February 2018
Mayon’s condition for the past 24 hours was characterized by relative quiescence after a period of weak lava fountaining and lava effusion from the summit crater. Between 9:03 AM and 10:46 AM, two (2) discrete events of lava fountaining lasting four (4) to six (6) minutes generated steam-laden plumes that rose 800 meters from the summit before drifting west-southwest. In the evening, lava effusion from the vent was observed to continue feeding lava flows that have maintained fronts at 3.3 kilometers, 4.5 kilometers and 900 meters on the Mi-isi, Bonga and Basud-Gullies, respectively, from the summit crater. One (1) lava-collapse event produced a pyroclastic density current (PDC) at 11:55 AM yesterday on Basud-Gully within 4 kilometers of the summit crater.
A total of fifty-one (51) volcanic earthquakes and sixteen (16) rockfall events were recorded by Mayon’s seismic monitoring network. Sulfur dioxide (SO2) emission was measured at an average of 2,787 tonnes/day on 26 February 2018. Deflation of the lower slopes that began on 20 February is still being recorded by electronic tilt. Nonetheless, overall electronic tilt and continuous GPS data indicate that the edifice is still swollen or inflated relative to November and October 2017, consistent with campaign Precise Leveling data acquired last week.
A. Pre-Emptive Evacuation (TAB B)
- A total of 16,380 families were pre-emptively evacuated in Region V due to Mt. Mayon phreatic eruption.
Source: DILG SitRep No. 04 as of 24 January 2018
B. Affected Population
As of 4:00 PM, 27 February 2018, a total of 23,526 families / 90,155 persons were affected in 61 barangays in the municipalities/cities of Bacacay, Camalig, Guinobatan, Ligao City, Daraga, Tabaco City, Malilipot, Santo Domingo (Libog), and Legazpi City in the Province of Albay (Region V).
Currently, a total of 17,454 families or 66,907 persons were served inside and outside evacuation centers (ECs):
Inside 57 ECs: 15,996 families / 61,448 persons
Outside ECs: 1,458 families / 5,459 persons
Since 14 January 2018, Mayon Volcano continues to show high levels of unrest resulting from repeated hazardous eruptions that have displaced tens of thousands of residents from the extended danger zone. The alert level remains at ‘4’ on the government‘s 5-point scale due to the impending danger of the volcanic activities, prohibiting authorities from allowing the return of the evacuees.
To assist the local government’s strategic decision making, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) published updated hazard maps to help understand the risks related to the eruption. Monsoon rains can exacerbate the danger to residents by causing flooding, landslides and lahar (mudflows), adding to the concerns of communities surrounding the volcano. The hazard maps of Mayon Volcano from PHIVOLCS together with the flood and landslide hazard maps from The Mines and Geosciences Bureau (MGB) can help the affected municipalities mitigate and minimize loss of lives and properties associated with this event.