Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 23 May – 29 May 2018

Agung | Bali (Indonesia) : PVMBG reported that although there were some periods of foggy conditions during 23-29 May, white plumes were occasionally observed rising as high as 400 m above Agung’s crater rim. At 0539 on 29 May an event generated an ash plume that rose 500 m above the crater rim and drifted SW. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone continued at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that there were 21 events and 19 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 21-28 May. Tephra was ejected as far as 1.3 km from the crater, and ash plumes rose as high as 3.2 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Ambae | Vanuatu : On 18 May a news article noted that the eruption from a cone in Ambae’s Lake Voui continued with minor activity at the vent. The article noted that widespread ashfall had significantly impacted food and water supplies, shelter, and the health of island residents. The Alert Level remained at 3 (on a scale of 0-5), and the report reminded residents to stay at least 3 km away from the active crater.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 23-29 May ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted W, WNW, and NW. Ash plumes drifted as far as 225 km NW on 28 May.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that during 19-20 May a thermal anomaly over Karymsky was identified in satellite images. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 23 and 26-28 May ash plumes from Langila rose to altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l. and drifted WSW, W, and NW.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 23-29 May white steam plumes from Mayon drifted WNW, WSW, and SW, sometimes rising 250-300 m above the crater rim. Crater incandescence was visible each night. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Reventador | Ecuador : During 23-28 May IG reported a high level of seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador. Steam, gas, and ash plumes rose 1.5 km above the crater rim and drifted NW on 23 May, and a plume of gas, water vapor, and ash rose 300 m on 26 May; cloudy weather prevented views of emissions on most days. A lava flow had advanced to 900 m on the NE flank. On 27 May incandescent blocks were observed rolling as far as 800 m down the flanks in multiple directions. An ash plume rose 3 km above the crater rim and quickly drifted W, causing ashfall in Papallacta (62 km SW), San Antonio de Pichincha (90 km W), Tabacundo (63 km WNW), Cayambe (57 km WNW), Puellaro (85 km WNW), and Puembo (80 km W).

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was comparable to the previous week; explosions averaged 35 per day during 21-27 May. Seismicity was dominated by long-period events and signals indicating emissions. Gas-and-ash plumes rose as high as 3.3 km above the crater rim and drifted 30 km NE, E, and SE. The MIROVA system detected nine thermal anomalies, and on 24 May the sulfur dioxide gas flux was high at 3,950 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 weak thermal anomaly over Sheveluch was identified in satellite images on 19-20 and 23-24 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0930 on 28 May generated a plume that rose 300 m above the crater rim and drifted SE.