Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 20 February – 26 February 2019

Agung | Bali (Indonesia) : PVMBG reported that at 1631 on 22 February an event at Agung generated an ash plume that rose 700 m and drifted E. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that incandescence from Minamidake crater (at Aira Caldera’s Sakurajima volcano) was occasionally visible during 18-25 February. At 0059 on 22 February an event generated a plume that rose 1 km above the crater rim and ejected material 600-900 m from the crater. During 22-25 February there were two events, one of which was explosive. Plumes rose as high as 1.2 km, and material as ejected as far as 900 m from the crater. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that unrest at Cleveland continued during 20-24 February, though no activity was detected in seismic or infrasound data. Elevated surface temperatures were identified in satellite images; weather clouds sometimes prevented views of the volcano. Satellite data showed continued subsidence of the lava dome with no evidence of new lava. On 25 February the Aviation colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 20-24 February ash plumes from Dukono rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted W, SW, SE, and E. The Alert Level remained at 2 (on a scale of 1-4), and visitors were 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 15-22 February that sent ash plumes to 3.6 km (11,800 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Great Sitkin | Andreanof Islands (USA) : On 25 February AVO reported that seismicity at Great Sitkin had decreased to background levels during the past month and there was no evidence of explosive activity. The Aviation colour Code was lowered to Green and the Volcano Alert Level was lowered to Normal.

Ibu | Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 25-26 February ash plumes from Ibu rose to altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l. and drifted NE and ENE. A thermal anomaly was also visible. 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.

Kadovar | Papua New Guinea : Based on satellite data and wind model data, the Darwin VAAC reported that on 21 February an ash plume from Kadovar rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted ESE.

Krakatau | Indonesia : PVMBG reported that an event at Anak Krakatau began at 1525 on 23 February and lasted four minutes and 31 seconds. An ash plume rose to about 610 m above sea level and drifted ENE. The Alert Level remained at 3 (on a scale of 1-4), and residents were warned to remain outside of the 5-km radius hazard zone from the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 15-21 February the volume of the lava dome in Merapi’s summit crater was unchanged from the previous few weeks. There were no apparent morphological changes; most of the extruded lava fell into the upper parts of the Gendol River drainage on the SE flank. White emissions rose as high as 375 m above the crater rim. On 18 February multiple block-and-ash flows traveled at most 1 km down the Gendol drainage. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 20 explosions per day occurred at Sabancaya during 18-24 February. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Although weather conditions sometimes prevented visual observations, gas-and-ash plumes were seen rising as high as 2.2 km above the crater rim and drifted 30 km SW. MIROVA detected two thermal anomalies. The report noted that the public should not approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 15-22 February Sheveluch’s lava dome continued to grow, extruding blocks on the N side, and producing hot avalanches and fumarolic plumes. A thermal anomaly was identified in satellite images daily. Video and satellite data recorded gas-and-steam plumes with variable ash content rising 4-5 km (13,100-16,400 ft) a.s.l. and drifting W and E. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that crater incandescence at Suwanosejima’s Ontake Crater was visible at night during 15-22 February. Small events were occasionally recorded, generating plumes that rose as high as 900 m above the crater rim. The Alert Level remained at 2 (on a 5-level scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba on 21 February generated a plume that rose 300 m and drifted NW. Frequent ash pulses were recorded that day. Ash emissions were frequent during 22-24 February, though of variable intensity and duration. Plumes rose as high as 300 m and drifted NW and SW. On 22 February ashfall was reported in Santa Cruz (31 km WSW) and Santa Ana, and a sulfur odor was evident in Moravia (31 km WSW). Cloudy weather conditions prevented visual observations of the vent during 25-26 February.

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