Roundup of Global Volcanic Activity – Ongoing activity for the week of 4 January-10 January 2017 (Cont.)
Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 3-9 January seismicity at Nevado del Ruiz continued to indicate unrest. Some of the seismic signals were associated with gas-and-ash emissions, as confirmed by webcam images and officials in the Parque Nacional Natural los Nevados. A low-energy thermal anomaly was identified by the MIROVA system on 9 January. On 6 January a gas, water vapor, and ash plume rose 2.5 km above the crater rim and drifted between SW and NE directions. A seismic event at 0745 on 8 January was associated with an ash emission which drifted SW. The Alert Level remained at III (Yellow; the second lowest level on a four-colour scale).
Nevados de Chillan | Chile : Based on a pilot observation, the Buenos Aires VAAC reported that on 6 January a dark-coloured fumarolic plume rose from Nevados de Chillán to an altitude of 2.9 km (9,500 ft) a.s.l. and drifted 4.5 km E. The webcam recorded the event as a small, sporadic puff that quickly dissipated; the emission was not identified in satellite images.
Reventador | Ecuador : During 4-10 January IG reported a high level of seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador. Although cloud cover often prevented visual observations, ash plumes were noted rising as high as 1 km above the crater and drifting W and NW during 6-7 January.
Semeru | Eastern Java (Indonesia) : Based on analysis of satellite images and information from PVMBG, the Darwin VAAC reported that on 9 January ash plumes from Semeru rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted N.
Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 30 December 2016-6 January 2017 lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome, and ash plumes that drifted about 100 km N and NE on 30 and 31 December. The Aviation Colour Code remained at Orange.
Sinabung | Indonesia : Based on PVMBG observations and satellite images, the Darwin VAAC reported that during 2-3 and 8-10 January ash plumes from Sinabung rose 3.6-6.4 km (12,000-21,000 ft) a.s.l. and drifted W, NE, and E. Plumes drifted as far as 55 km E ln 8 January. A thermal anomaly was detected on 9 January.
Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that during 4-5 January ash plumes from Suwanosejima rose to altitudes of 1.2-1.8 km (4,000-6,000 ft) a.s.l. and drifted SE and W.