Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 28 November - 4 December 2018

Aira | Kyushu (Japan) : JMA reported that nine events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) were recorded during 26 November-3 December, producing ash plumes that rose as high as 1.8 km above the crater rim. Incandescence was periodically visible at night. An explosion at 0218 on 1 December generated a plume that rose 2.5 km and ejected tephra 1.1 km from the crater. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : On 1 December the Darwin VAAC reported that ash plumes from Bagana were visible in satellite images drifting SE at an altitude of 3 km (10,000 ft) a.s.l. The report also noted the presence of a strong thermal anomaly, and that ash plumes which previously rose to 6.1 km (20,000 ft) a.s.l. had dissipated. Steam plumes drifted SE on 2 December.

Chiles-Cerro Negro | Colombia-Ecuador : Servicio Geológico Colombiano (SGC) reported that a seismic swarm below Cerro Negro de Mayasquer and Chiles volcanoes began at 0100 on 3 December. The events were classified as volcano-tectonic, with epicenters located up to 6 km from the summit of Chiles volcano, at depths of less than 8 km (4.7 km a.s.l.). The maximum local magnitude was 2.3. From the beginning of the swarm until the time of the report posting (1640) there were about 5,400 recorded events, making the swarm the largest since 2015. The report also noted that seismicity had gradually been increasing in recent weeks. The Alert Level remained at Yellow (level 2 of 4).

Copahue | Central Chile-Argentina border : The Buenos Aires VAAC reported that on 2 December a narrow ash plume from Copahue was visible in satellite images drifting ESE.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 21-27 November ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted NE, E, and SE. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 23-30 November that sent ash plumes to 4 km (13,100 ft) a.s.l. Ash plumes drifted E. A weak thermal anomaly was identified in satellite data on 24 November, and ashfall was reported in Severo-Kurilsk on 27 and 29 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kadovar | Papua New Guinea : Based on satellite data and wind model data, the Darwin VAAC reported that during 27-28 November ash plumes from Kadovar rose to an altitude of 0.9 km (3,000 ft) a.s.l. and drifted SE and E. On 2 December ash plumes rose to 1.2 km (4,000 ft) a.s.l. and drifted WSW and W.

Kirishimayama | Kyushu (Japan) : JMA reported that vigorous fumarolic activity on the S side of Iwo-yama (also called Ioyama), on the NW flank of the Karakuni-dake stratovolcano in the Kirishimayama volcano group, continued during 30 November-3 December. Fumarolic plumes rose 100 m above the vent, and hot mud was ejected from the vent. A hot pool of water persisted on the S side of the area. Fumarolic plumes rose 50 m above a vent 500 m W of Iwo-yama. The Alert Level remained at 2 (the second lowest level on a scale of 1-5).

Krakatau | Indonesia : PVMBG reported that events at Anak Krakatau were recorded at 1131 on 1 December, at 1408 on 2 December, and at 0816 on 3 December, each lasting between 46 and 69 seconds. Ash plumes from the events rose 500-700 m and drifted NE and N. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Kuchinoerabujima | Ryukyu Islands (Japan) : JMA reported that during 28 November-3 December intermittent events at Kuchinoerabujima’s Shindake Crater generated plumes that rose as high as 1.5 km above the crater rim. The Alert Level remained at 3 (on a scale of 1-5).

Merapi | Central Java (Indonesia) : PVMBG reported that during 23-29 November the lava dome in Merapi’s summit crater grew at a rate of 2,500 cubic meters per day. By 29 November the volume of the dome, based on photos taken from the SE, was an estimated 329,000 cubic meters. White emissions of variable density rose a maximum of 400 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Popocatepetl | Mexico : CENAPRED reported that each day during 28 November-3 December there were 16-79 steam-and-gas emissions from Popocatépetl. Periods of volcanic tremor were detected almost daily. Explosions at 0509 and 0922 on 2 December ejected incandescent material onto the upper flanks, and generated ash plumes that rose 2.5 km above the crater rim and drifted NE. More explosions at 1543 and 1745 produced ash plumes that rose 1.5 km and drifted NE. The Alert Level remained at Yellow, Phase Two (middle level on a three-colour scale).

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported a one-minute-long eruption at Rincón de la Vieja began at 1054 on 3 December. Weather conditions prevented webcam views and estimates of plume heights.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 21 explosions per day occurred at Sabancaya during 26 November-2 December. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 2.5 km above the crater rim and drifted 30 km N, E, and SE. MIROVA detected eight thermal anomalies, and on 28 November the sulfur-dioxide gas flux was high at 4,600 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images on 23 November; weather clouds prevented views of the volcano during 24-30 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that four explosions at Suwanosejima’s Ontake Crater were recorded during 22-30 November. The highest ash plume rose 2 km, and material was ejected 300 m from the crater. Ashfall was reported in an area 4 km SSW on 23 November. Crater incandescence was visible at night. The Alert Level remained at 2 (on a 5-level scale).

Turrialba | Costa Rica : OVSICORI-UNA reported intermittent pulses of ash and some periods of continuous ash emissions from Turrialba during 28 November-3 December. Ash plumes rose as high as 500 m above the crater rim and drifted N, NW, and SW. Ashfall was reported in Santo Domingo (36 km WSW) on 2 December.