Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 22 August -28 August 2018

Aira | Kyushu (Japan) : JMA reported that there were three events and 12 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 20-27 August, with ash plumes rising as high as 2.1 km above the crater rim and material ejected as far as 1.3 km. Crater incandescence was sometimes visible at night. The Alert Level remained at 3 (on a 5-level scale).

Ambrym | Vanuatu : On 22 August the Vanuatu Meteorology and Geo-hazards Department reported that the lava lakes in Ambrym’s Benbow and Marum craters continued to be active, and produced sustained and substantial gas-and-steam emissions. The Alert Level remained at 2 (on a scale of 0-5); the report reminded the public to stay outside of the Permanent Danger Zone defined as a 1-km radius from Benbow Crater and a 2.7-km radius from Marum Crater.

Cleveland | Chuginadak Island (USA) : Low-level unrest at Cleveland continued, though on 22 August AVO noted a pause in activity and lowered the Aviation colour Code to Yellow and the Volcano Alert Level to Advisory. The report noted that elevated surface temperatures were identified in satellite images the previous day, suggestive of hot gas emissions from the summit crater vents.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 22-23 and 25-28 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 17-24 August that sent ash plumes as high as 5.2 km (17,100 ft) a.s.l. Ash plumes drifted 235 km SE during 21-22 August, and a thermal anomaly was visible during 21-23 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : PVMBG reported that at 0838 on 24 August an event at Ibu generated an ash plume that rose 800 m above the crater rim and drifted S. Seismicity was characterized by explosions and 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.

Kilauea | Hawaiian Islands (USA) : HVO reported that during an overflight on 25 August a small lava pond was visible deep within the vent at Kilauea’s Fissure 8 cone; the pond was no longer visible on 27 August. Lava continued to ooze into the ocean and produce minimal laze plumes, but by 27 August only a small single breakout from the Kapoho Bay lobe was active. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Pacaya | Guatemala : Based on information from INSIVUMEH, CONRED reported a slight increase in explosive activity at Pacaya, with 3-5 explosions per hour recorded by the seismic network. A 600-m-long lava flow originating from Mackenney Crater was visible on NW flank.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 25 per day during 20-26 August. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 4.5 km above the crater rim and drifted 50 km SE, E, NE, and N. The MIROVA system detected seven thermal anomalies, and on 25 August the sulfur dioxide gas flux was high at 2,230 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Semeru | Eastern Java (Indonesia) : Based on analysis of satellite images and wind model data, the Darwin VAAC reported that during 23-27 August ash plumes from Semeru rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SW, W, NW, and SE.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that satellite images showed a thermal anomaly over Sheveluch on 17, 19, and 23 August; cloudy weather prevented views of the volcano on the other days during 17-24 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sierra Negra | Isla Isabela (Ecuador) : IG reported that during 20-21 August both steam-and-gas emissions and incandescence from lava flows were visible on the Sierra Negra webcam. No activity was noted when the weather was clear during 22-28 August.

Turrialba | Costa Rica : OVSICORI-UNA reported that during 27-28 August emissions from Turrialba rose continuously to 200 m above the crater rim, and drifted SW.

Yasur | Vanuatu : The Vanuatu Meteorology and Geo-hazards Department reported that ongoing explosions at Yasur were sometimes strong during August. The Alert Level remained at 2 (on a scale of 0-4). VMGD reminded residents and tourists that hazardous areas were near and around the volcanic crater, within a 395-m-radius permanent exclusion zone, and that volcanic ash and gas could reach areas impacted by trade winds.