Friday 24 August 2018

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 15 August -21 August 2018

Agung | Bali (Indonesia) : According to the Darwin VAAC, a webcam recorded a diffuse ash emission from Agung rising to an altitude of 3.3 km (11,000 ft) a.s.l. and drifting W. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone was stable at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that there were four events and nine explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 13-20 August, with ash plumes rising as high as 1.7 km above the crater rim and material ejected as far as 900 m. Crater incandescence was visible at night. The Alert Level remained at 3 (on a 5-level scale).

Ambae | Vanuatu : According to news reports all 10,000 residents of Ambae had been evacuated to Espiritu Santo (W) and Maewo (NE) islands by 14 August.

Cleveland | Chuginadak Island (USA) : AVO reported that unrest at Cleveland continued during 15-20 August, though nothing significant was detected in seismic or infrasound data. Steaming from the crater was sometimes visible in clear webcam views, and elevated surface temperatures were occasionally identified in satellite images. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Copahue | Central Chile-Argentina border : The Buenos Aires VAAC reported that during 14-15 August diffuse steam emissions with possible ash were visible in webcam views rising to an altitude of 3.6 km (12,000 ft) a.s.l.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 15-21 August ash plumes from Dukono rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted NNW, NE, and E.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 11-17 August that sent ash plumes as high as 4.5 km (14,800 ft) a.s.l. An ash plume drifted 52 km SE during 10-11 August, and a thermal anomaly was identified in satellite images on 12 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that during 18-21 August explosions at Fuego generated ash plumes that rose as high as 850 m above the crater and drifted 12 km NW, W, and SW. Incandescent material was ejected 150 m above the crater rim, and caused avalanches of material within the crater area and down drainages on the flanks. According to CONRED, as of 22 August, the number of people confirmed to have died due to the 3 June pyroclastic flows was 169, and 256 remained missing.

Ibu | Halmahera (Indonesia) : PVMBG reported that at 1742 on 20 August an event at Ibu generated an ash plume that rose 1.2 km above the crater rim. 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 10 August; cloud cover prevented views during 11-17 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : On 17 August HVO lowered the Alert Level for Kilauea to Watch (the Aviation colour Code remained at Orange), noting reduced activity over the previous several days. Specifically, no collapse events had occurred at the summit since 2 August, lava ceased flowing in the channel from the Fissure 8 cone on 6 August, seismicity and ground deformation at the summit were negligible, and the combined rate of sulfur dioxide emission from the summit and the LERZ were lower than any time since late 2007. The small lava pond in Fissure 8 had crusted over by 17 August, with no observed incandescence. Lava continued to ooze into the ocean at a few areas, causing minimal laze plumes. During an overflight on 20 August gas jets ejected spatter from a small incandescent area deep within the Fissure 8 cone.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 27 per day during 13-19 August. Hybrid earthquakes were infrequent and low-magnitude. Gas-and-ash plumes rose as high as 3.7 km above the crater rim and drifted 50 km SE, E, and NE. The MIROVA system detected nine thermal anomalies, and on 19 August the sulfur dioxide gas flux was high at 3,100 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 satellite images showed a thermal anomaly over Sheveluch during 12-13 August; cloudy weather prevented views of the volcano on the other days during 10-17 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 lava effusion at Sierra Negra continued at variable intensities. The most intense pulses, recorded on 4 and 9 August, were accompanied by major episodes of seismic tremor; activity slightly declined after 9 August. On 15 August satellite images showed lava from Fissure 4 continuing to enter the ocean.

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