Volcanos

Roundup of Global Volcanic Activity - Ongoing Activity for the week of 23 August - 29 August 2017

Aira | Kyushu (Japan) : JMA reported that 17 explosive events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 21-28 August ejected material as far as 800 m. Ash plumes rose as high as 1.4 km above the crater rim. 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 24-28 August ash plumes from Bagana rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted WNW, W, and SW.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 18-25 August a daily thermal anomaly over Bezymianny was identified in satellite images. A lava flow continued to flow down the W flank of the dome; incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that a satellite image of Bogoslof acquired at 0628 on 24 August showed elevated surface temperatures and a small plume that was most likely steam drifting 17 km S. During 24-25 August a robust steam plume drifting 70 km SE and elevated surface temperatures were identified in satellite data. A four-minute-long explosion that began at 1629 on 26 August generated an eruption cloud that rose 8.2 km (27,000 ft) a.s.l. and drifted SE. The event was also observed in seismic and infrasound data, and one lightning stroke was detected. Three short-duration eruptive events occurred during 27-28 August. The first, a two-minute-long explosion at 1508 on 27 August, produced a volcanic cloud that rose 7.9 km (26,000 ft) a.s.l. and drifted SE. The second event started at 0323 on 28 August and lasted 25 minutes. The resulting small cloud drifted ESE and quickly dissipated. The third event was detected at 1117 on 28 August and generated a small volcanic cloud that rose 7.6-9.1 (25,000-30,000 ft) a.s.l. Slightly elevated surface temperatures were observed in a few satellite images during 28-29 August. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that elevated surface temperatures at Cleveland were identified in satellite data during 25-28 August. Small vapor plumes from the summit were observed in webcam images during 28-29 August. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 23-28 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N, NW, and W.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions on 22 August generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. and drifted SW. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that on 25 August lahars descended the Pantaleón, Cenizas, El Jute, and Las Lajas drainages on Fuego’s W, SSW, and SE flanks. The lahar in the Pantaleón river (fed by the Santa Teresa and El Mineral rivers) was 35 m wide, 2.5-3 m deep, and carried trees and blocks more than 2-3 m in diameter. The Cenizas river lahar was about 25 m wide, 3 m deep, and carried blocks up to 2 m in diameter. The lahars in El Jute and Las Lajas drainages were 20 m wide, 1.5 m deep, and carried tree debris and blocks up to 2 m in diameter. Explosions during 26-29 August generated ash plumes that rose as high as 950 m above the crater and drifted 7-12 km SW, W, and NW. Incandescent material was ejected 100-200 m above the crater rim, and caused avalanches of material around the crater area. Explosions were audible within a 20-km radius, and shock waves vibrated local structures. Ash fell in areas downwind including Panimache I and II, Morelia, Finca Palo verde, Sangre de Cristo, and El Porvenir. On 29 August lahars 10 m wide and 1.5 m deep descended the Santa Teresa and El Mineral drainages, carrying tree debris and blocks up to 2 m in diameter.

Kilauea | Hawaiian Islands (USA) : During 23-29 August 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. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO warned of the potential for larger-scale delta collapses.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that on 19 August explosions at Klyuchevskoy generated ash plumes that rose 6-7 km (19,700-23,000 ft) a.s.l.; the plumes drifted 140 km NW initially, and then 270 km SW and 90 km NE. Ash plumes during 20-25 August drifted as far as 560 km NW, W, and SW. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise that began on 14 July ended at 0300 on 28 August, as indicated by the disappearance of tremor. OVPF noted that seismic events beneath the SE part of the Enclos Fouqué region continued to be recorded, and carbon dioxide levels in the soil remained high.

Poas | Costa Rica : OVSICORI-UNA reported that events at Poás at 0920 and 0930 on 24 August and at 0945 on 29 August generated plumes that rose 500-600 m above the crater rim.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar to the previous week; there was an average of 46 explosions recorded per day during 21-27 August. The earthquakes were dominated by long-period signals and signals indicating emissions, with fewer numbers of hybrid events recorded. Gas-and-ash plumes rose 3.4 km above the crater rim and drifted no more than 50 km SE and NW. The MIROVA system detected eight thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images during 18-25 August. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 23-27 August ash plumes from Sinabung rose 4-4.9 km (13,000-16,000 ft) a.s.l. and drifted E and ESE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that during 24-25 August ash plumes from Suwanosejima rose to altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted E and NE.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0715 on 24 August generated a plume that rose 400 m above the crater rim and drifted NW. Another event at 1025 on 28 August produced a plume that rose 300 m and drifted NW.