Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 14 February - 20 February 2018

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 14-20 February daily activity at Mayon continued to be characterized by lava effusion from the summit crater, rockfalls, lava fountains, steam emissions, advancing lava flows on the flanks, and pyroclastic flows. Weak and sporadic lava fountaining events each lasted between 5 and 239 minutes, and were sometimes accompanied by rumbling sounds audible with a 10-km radius. Heavy rainfall on 14 February caused lahars in the Anoling drainage, and sediment-laden streams in most channels where pyroclastic flow deposits were emplaced. During 16-17 February lava fountains were 200-500 m tall and generated steam plumes that drifted SW, WSW, and NW. A lava-fountaining event that began at 0103 on 17 February lasted for 12 hours and 18 minutes. Lava flows 3.3 km, 4.5 km, and 900 m long in the Mi-isi (S), Bonga (SE), and Basud (E) drainages, respectively, continued to be active. Pyroclastic flows traveled 4.2-4.6 km in the Mi-isi, Bonga, and Basud drainages. The Alert Level remained at 4 (on a 0-5 scale) and the public was warned to remain outside of the Danger Zone, defined as an area within an 8-km radius.

Sinabung | Indonesia : PVMBG reported that at 0853 on 19 February a large explosive event at Sinabung generated a dark gray plume with a high volume of ash that rose at least to 16.8 km (55,000 ft) a.s.l. According to the Darwin VAAC, ash plumes that were identified in satellite images, recorded by webcams, and reported by PVMBG continued to rise throughout the day to 13.7 km (45,000 ft) a.s.l. and drift 320 km NNW. Parts of the ash plumes drifted in multiple directions at lower altitudes. As many as 10 pyroclastic flows were observed, traveling as far as 4.9 km SSE and 3.5 km E. Ash and tephra as large as pebbles fell in areas downwind including Simpang Empat (7 km SE), the Namanteran district, Pqyung (5 km SSW), Tiganderket (7 km W), Munthe, Kutambaru (20 km NW), Perbaji (4 km SW), and Kutarayat. Conditions in five districts were so dark that visibility was only about 5 m. Some residents outside of the evacuation zone self-evacuated. The event was possibly the largest since the beginning of the current eruption, which began in September 2013. The Alert Level remained at 4 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions of 7 km on the SSE sector, 6 km in the ESE sector, and 4 km in the NNE sector.