Volcanos

Global Volcanic Activity - Ongoing Activity for the week of 21 August - 27 August 2019

Aira | Kyushu (Japan) : JMA reported that very small eruptive events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) occasionally occurred during 19-26 August. The Alert Level remained at 3 (on a 5-level scale).

Asosan | Kyushu (Japan) : JMA reported that during 18-23 August ash plumes rose from Asosan and drifted N and NW. Crater incandescence was visible at night. An eruption recorded during 1130-1945 on 25 August generated ash plumes that drifted E. The sulfur dioxide emission rate was 1,800 tons per day on 21 August and remained high on 25 August. The Alert Level remained at 2 (on a scale of 1-5).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and information from PVMBG, the Darwin VAAC reported that during 21-27 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted mainly E, NE, N, and NW. The Alert Level remained at 2 (on a scale of 1-4), and the public was 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 17-23 August that sent ash plumes up to 3 km (10,000 ft) a.s.l. and drifted SE. A thermal anomaly was identified in satellite images on 16 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : PVMBG reported that at 0704 on 22 August an ash plume from Ibu rose at least 800 m above the summit and drifted W. Seismicity was characterized by an explosion signal and earthquakes indicating rock avalanches. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

Karangetang | Siau Island (Indonesia) : PVMBG reported that during 19-25 August lava continued to effuse from Karangetang’s Main Crater (S) and Dua Crater (N). Avalanches of incandescent material traveled 1-1.5 km SW down the Nanitu and Pangi drainages, as far as 2 km down a drainage W of Pangi, and as far as 1.8 km down the Sense drainage. Sometimes dense white plumes rose to 200 m above the summit. The Alert Level remained at 2 (on a scale of 1-4).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that ash plumes from Karymsky were visible in satellite images drifting 500 km SW during 20-22 August. Explosions on 21 August produced ash plumes that rose to 6 km (19,700 ft) a.s.l. A thermal anomaly over the volcano was visible during 21-22 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was visible in satellite images during 17-23 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that Anak Krakatau’s seismic network recorded 27 eruptive events during 19-25 August. The events were not followed by visible ash emissions, even though there were favorable weather conditions for viewing. An eruption recorded by a summit webcam at 0755 on 22 August produced a white, gray, and black ash plume that rose 100-400 m from the crater rim and drifted N and NW. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km-radius hazard zone from the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 19-25 August the lava-dome volume at Merapi did not change and was an estimated 461,000 cubic meters, based on analyses of drone images on 8 August. Extruded lava fell into the upper parts of the SE flank, generating block-and-ash flows that traveled as far as 1.9 km down the Gendol drainage: twice on 20 August, once each on 22 and 24 August, and 10 times during 25-27 August. At 1809 on 27 August a block-and-ash flow traveled 2 km. Diffuse white plumes rose as high as 350 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to stay outside of the 3-km exclusion zone.

Reventador | Ecuador : IG reported that during 21-27 August seismic data from Reventador’s network indicated a high level of seismic activity, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Weather often prevented views of the summit area, although during clear conditions ash-and-steam plumes were visible rising as high as 1 km above the crater rim and drifting W, NW, and N. Crater incandescence was periodically observed at night. Blocks were observed rolling 800 m down the flanks during 26-27 August.

Sangeang Api | Indonesia : The Darwin VAAC reported that during 21-26 August intermittent ash plumes from Sangeang Api were identified in satellite images rising to 3 km (10,000 ft) a.s.l. and drifting W and WNW. The Alert Level remained at 2 (on a scale of 1-4).

Semisopochnoi | United States : AVO reported that during 17-23 August seismicity at Semisopochnoi remained elevated and was characterized by periods of continuous tremor and discrete low-frequency earthquakes; seismic data went offline starting sometime on 17 August, though was available by around 22 August. Ground-coupled airwaves, indicative of explosive activity, were sometimes recorded in seismic data; an infrasound signal was recorded during 23-24 August. Cloudy weather often prevented satellite views of the volcano, though a steam plume was visible on 18 August and sulfur dioxide emissions were detected during 21-22 August. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 17-23 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : The Tokyo VAAC reported that on 26 August a plume from Suwanosejima was visible in satellite images rising to 2.1 km (7,000 ft) a.s.l. The Alert Level remained at 2 (on a 5-level scale).

Ubinas | Peru : IGP reported that during 20-26 August blue-coloured gas plumes from Ubinas rose above the crater and eight thermal anomalies were recorded by the MIROVA system. The number of seismic events was 1,736 (all under M 2.4), and there was an increase in the magnitude and number of hybrid and long-period events. Around 1030 on 26 August an ash emission rose to heights below 2 km above the crater rim. Continuous ash emissions on 27 August were recorded by satellite and webcam images drifting S and SW. The Alert Level remained at Orange (the second highest level on a four-colour scale) and the public were warned to stay outside of a 15-km radius.