Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 26 September - 2 October 2018

Aira | Kyushu (Japan) : JMA reported that occasional, very small, events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 25 September-1 October generated plumes that rose 400 m above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Aira | Kyushu (Japan) : JMA reported that occasional, very small, events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 25 September-1 October generated plumes that rose 400 m above the crater rim. 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 26 September-2 October ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW, N, NE, and E.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 21-28 September that sent ash plumes to 4 km (13,100 ft) a.s.l. Satellite images showed a thermal anomaly over the volcano on 23 and 27 September, and ash plumes drifting as far as 68 km SE during 23-24 and 26-27 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that during 24-30 September activity at Etna was characterized by gas emissions at the summit craters, with periodic Strombolian activity from vents in Bocca Nuova, Northeast Crater (NEC), and New Southeast Crater (NSEC). Strombolian activity at the N vent in Bocca Nuova (BN-1) ejected incandescent material almost as high as the W crater rim. No eruptive activity was observed at BN-2, though it produced explosions deep in the crater. A new high-temperature vent producing gas emissions was noted on 1 October in the same place a fumarole had been observed the previous week. Ash emissions from NSEC were sometimes accompanied by ejected incandescent material. Gas emissions increased at Voragine Crater from a vent that formed on 7 August 2016 on the E rim of the crater. NEC produced frequent brown-gray ash emissions, and ejected blocks and bombs, from a vent located in the W part of the crater floor.

Ibu | Halmahera (Indonesia) : Based on satellite images and wind model data, the Darwin VAAC reported that on 28 and 30 September ash plumes from Ibu rose to 1.8 km (6,000 ft) a.s.l. and drifted NE and N.

Kadovar | Papua New Guinea : An ash plume from Kadovar was visible in satellite images on 28 September drifting SE at an altitude of 2.1 km (7,000 ft) a.s.l. On 1 October an ash plume rose to 2.7 km (9,000 ft) a.s.l. and drifted W.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 22-24 September, and ash plumes were visible drifting 365 km E during 22-23 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported no significant incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 26 September-2 October, though a small amount of fuming was visible during the day. Seismicity and ground deformation remain low at the summit, and small aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. Sulfur dioxide emissions from the summit and the LERZ were low. On 1 October a rockfall at Pu'u 'O'o produced a small ash plume. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Krakatau | Indonesia : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 25 September-2 October ash plumes from Anak Krakatau rose to altitudes of 1.2-2.1 km (4,000-7,000 ft) a.s.l. and drifted W, WSW, 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.

Manam | Papua New Guinea : RVO reported that pale-gray-to-brown ash plumes rose from Manam’s Southern Crater during 20 September-1 October. Activity was most intense on 24 September, with an increased amount of ash emissions, and occasional weak roaring and rumbling noises. Based on seismic data an eruption at Main Crater began during 0100-0130 on 1 October, peaked around 0200, and ended at 1200 (though a sharp decline was recorded at 1215). Ash plumes rose at least several hundred meters above the crater rim, though darkness obscured visual observations. Islanders described loud roaring and rumbling noises, as well as loud banging noises. Residents of Tabele on the SW side of the island observed bright summit incandescence, which was also visible from the Bogia Government Station on the mainland (22 km SSW). Scoria and minor amounts of ash fell in Jogari and villages to the N.

Merapi | Central Java (Indonesia) : PVMBG reported that during 21-27 September the new lava dome in Merapi’s summit crater continued to slowly grow. By 27 September the volume of the lava dome was an estimated 129,000 cubic meters, and the growth rate was 1,000 cubic meters per day (slower than the previous week). White emissions of variable density rose a maximum of 450 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.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 21 per day during 24-30 September. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3.7 km above the crater rim and drifted 50 km E, SE, and SW. The MIROVA system detected six thermal anomalies, and on 29 September the sulfur dioxide gas flux was high at 3,250 tons/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 data during 20, 23, and 27 September; weather clouds prevented views on the other days during 21-28 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that at 0915 on 27 September an event at Turrialba produced a passive ash plume that rose 200 m above the crater and drifted NW. During 30 September-1 October ash emissions rose as high as 500 m above the crater rim and drifted NW and NE.