Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 12 September -18 September 2018

Aira | Kyushu (Japan) : JMA reported that there were 13 events and also 13 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 10-18 September, with ash plumes rising as high as 1.8 km above the crater rim and material ejected as far as 1.1 km. Crater incandescence was visible at night. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 12-18 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : KVERT reported that a thermal anomaly over Ebeko was identified in satellite images during 7, 9, and 12-13 September. Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E, observed explosions that sent ash plumes to 3.4 km (11,200 ft) a.s.l. and occasional incandescence during 10-13 September; ash plumes visible in satellite data drifted 113 km SE and NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 7 September. Dense and continuous ash emissions from the crater were visible on 10 September. Explosions during 10-11 September generated ash plumes identified in satellite images rising 5-6 km (16,400-19,700 ft) a.s.l. and drifting about 860 km NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported minor incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 12-15 September, and that small amounts of fuming rose from a small spatter cone located towards the back of the Fissure 8 cone during 12-18 September. Seismicity and ground deformation remain low at the summit, and aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (less than 1,000 tonnes/day) were lower than any time since late 2007. Small collapses at Pu'u 'O'o Crater during 12-14 September generated visible dust plumes. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Krakatau | Indonesia : Based on satellite data, the Darwin VAAC reported that during 11-13 and 17-18 September ash plumes from Anak Krakatau rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted NW, W, and SW. 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.

Merapi | Central Java (Indonesia) : PVMBG reported that during 10-16 September the new lava dome in Merapi’s summit crater continued to slowly grow. By 16 September the volume of the lava dome was an estimated 112,000 cubic meters, and the growth rate was 1,600 cubic meters per day. White emissions of variable density rose 20 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and resident were warned to remain outside of the 3-km exclusion zone.

Nevados de Chillan | Chile : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) and ONEMI reported the continuing, slow growth of the lava dome in Nevados de Chillán’s Nicanor Crater during 11-17 September. Gas emissions persisted, and sometimes contained ash. Periodic explosions sometimes ejected material that was deposited around the crater. Notably, at 0057 on 12 September, an explosion associated with a partial dome-collapse event ejected incandescent material 700 m above the crater rim and onto the flanks. An explosion at 2224 on 13 September generated ash plumes that rose 2.5 km above the crater rim. The event also ejected incandescent material to the SE, and generated a pyroclastic flow that traveled as most 400 m E. The Alert Level remained at Orange, the second highest level on a four-colour scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the communities of Pinto, Coihueco, and San Fabián.

Popocatepetl | Mexico : CENAPRED reported that each day during 12-17 September there were 64-189 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. Nighttime crater incandescence was sometimes visible. Explosions were detected almost every day: eight on 12 September; one on 14 September; five on 15 September; three on 16 September. A series of emissions and explosions accompanied by tremor began at 0425 on 17 September and lasted for 365 minutes; incandescent tephra was ejected. The Alert Level remained at Yellow, Phase Two.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 13 per day during 10-16 September. 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, NE, and SE. The MIROVA system detected seven thermal anomalies, and on 12 September the sulfur dioxide gas flux was high at 2,060 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Sangay | Ecuador : Based on satellite images and wind model data, the Washington VAAC reported that on 11, 13, 15, and 17 September ash emissions from Sangay rose to 5.8-6.4 km (19,000-21,000 ft) a.s.l. and drifted SW and W. A thermal anomaly was visible each day, and also on 16 September.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite data during 7-8 and 12-13 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that during 12-13 September eruptive events at Suwanosejima’s Ontake Crater generated plumes that rose 1.1 km above the crater rim. Tremor increased, and nighttime crater incandescence was also visible. The Alert Level remained at 2 (on a 5-level scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that passive gas-and-ash emissions from Turrialba were continuous in September through the 13th. Events during 17-18 September produced plumes that rose 300 m above the crater and drifted SW and NW.