Roundup of Global Volcanic Activity – Ongoing Activity for the week of 20 December – 26 December 2017
Aira | Kyushu (Japan) | 31.593°N, 130.657°E : JMA reported that very small events occurred at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 18-25 December. An event at 0514 on 25 December ejected material as far as 500 m from the crater. The Alert Level remained at 3 (on a 5-level scale).
Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 25-26 December ash plumes from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NE.
Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 20-25 December ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE, E, SE, and S.
Ebeko | Paramushir Island (Russia) : KVERT reported that on 16 December an ash plume from Ebeko was identified in satellite images drifting about 15 km SSW. A thermal anomaly was also visible. Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E, observed ash plumes from explosions rising as high as 3.5 km (7,500 ft) a.s.l. during 18-19 and 21-22 December. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).
Karymsky | Eastern Kamchatka (Russia) : KVERT reported that an ash plume from Karymsky was identified in satellite data drifting 114 km ENE on 14 December. No further ash emissions were noted afterwards; the Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale) on 24 December.
Kilauea | Hawaiian Islands (USA) : During 20-26 December HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.
Nevados de Chillan | Chile : On 19 December Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported an increase in activity at Nevados de Chillán’s Volcán Arrau dome complex during the previous three days. The activity was characterized by minor explosions occurring at a rate of four events per hour. Gas-and-tephra plumes rose 1 km above the crater rim. POVI reported that on 20 December explosions ejected incandescent material above the crater rim. The Alert Level remained at Yellow, the middle level on a three-colour scale, and the public was reminded not to approach the craters within a 3-km radius.
Oraefajokull | Iceland : On 22 December IMO reported that activity at Öræfajökull had been fairly stable during the previous weeks, though still above background levels; the Aviation colour Code remained at Yellow. In December the largest earthquake detected was a M2.5, but most events were smaller than M1. Earthquakes were located close to the caldera at depths between 2 and 10 km.
Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 19-21 December. The Aviation colour Code remained at Orange.
Sinabung | Indonesia : Based on observations by PVMBG, satellite images, and model data, the Darwin VAAC reported ash plumes from Sinabung during 20-23 December. The plumes rose 3.7-4.9 km (12,000-16,000 ft) a.s.l. during 20-21 December and drifted E and SW; weather clouds prevented estimates of plume altitudes on the other days.