Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 18 March 2020 – 24 March 2020

Aira | Kyushu (Japan) : JMA reported that during 16-23 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. Occasional eruptive events were recorded along with seven explosions. Ash plumes rose 2.8-3 km above the crater rim and material was ejected 1.1-1.7 km away from the crater. The Alert Level remained at 2 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 18-24 March ash plumes from Dukono rose to 1.5-2.3 km (5,000-8,000 ft) a.s.l. and drifted in multiple directions. 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 bursts of gas, steam, and a small amount of ash that rose up to 2.5 km (8,200 ft) a.s.l. on 13 and 17 March. Ash plumes drifted NE and SE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : On 16 March INSIVUMEH reported an increased number of avalanches at Fuego, traveling down the Ceniza (SSW), Trinidad (S), and Las Lajas (SE) ravines. A 600-m-long lava flow advanced down the Trinidad drainage. Weak explosive activity accompanied lava effusion. There were 4-12 explosions per hour recorded at Fuego during 17-24 March, generating ash plumes that rose as high as 1.1 km above the crater rim and generally drifted 10-22 km S, SW, and W. Almost daily ashfall was reported in several areas downwind including Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I and II (8 km SW), Finca Palo Verde, San Pedro Yepocapa (8 km NW), Sangre de Cristo (8 km WSW), El Porvenir (8 km ENE), and La Cruz. Explosions sometimes produced shock waves that rattled nearby houses and were felt in communities within a 25-km radius. Incandescent material was ejected 100-400 m high and caused avalanches of material that occasionally traveled long distances (reaching vegetated areas) down the Seca (W), Taniluyá (SW), Ceniza, Trinidad, Honda, and Las Lajas ravines. Lava flows of variable lengths (400-1,000 m) descended the Trinidad and Ceniza ravines each day but were inactive by the evening of 23 March.

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that during 18-19 March ash plumes from Ibu rose to 2.1 km (7,000 ft) a.s.l. and drifted W based on satellite images and weather models. 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.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that Strombolian activity at Klyuchevskoy was visible during 13-20 March, and the number of hot avalanches descending all of the flanks continued to increase. A bright thermal anomaly was identified daily in satellite images. Gas-and-steam plumes containing some ash drifted as far as 170 km E, NE, and N at altitudes of 5.5-6.5 km (18,000-21,300 ft) a.s.l. during 15 and 18-19 March. Vulcanian activity was visible on 19 March. The Aviation colour Code remained at Orange.

Krakatau | Indonesia : PVMBG reported that on 18 March a dense white-gray plume rose 300 m above the summit of Anak Krakatau and drifted S. The event lasted just over 10 minutes based on seismic data. 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.

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that small and periodic ash-and-gas emissions from Nevado del Ruiz were visible in satellite and webcam images during 18-24 March. These emissions drifted NE and SE. A gas-and-steam plume rose 1.5 km above the crater rim on 23 March. The Alert Level remained at 3 (Yellow; the second lowest level on a four-colour scale).

Pacaya | Guatemala : INSIVUMEH reported that during 17-24 March Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 100 m above the crater rim. Multiple lava flows (as many as four per day) traveled 100-300 m NW, W, and SW flanks.

Popocatepetl | Mexico : CENAPRED reported that each day during 17-23 March there were 74-182 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. An explosion at 2210 on 17 March ejected incandescent material onto the flanks and produced an ash plume that rose 1.2 km above the crater rim and drifted SE. Minor ashfall was reported in the municipalities of Tetela del Volcán (20 km SW), San Andrés and Hueyapan (16 km SW), and Ocuituco (24 km SW) during 17-18 March. Some emissions were accompanied by incandescent material ejected out of the crater between 2229-2315 on 18 March. An explosion at 1928 on 19 March ejected incandescent material a short distance from the crater. On 22 March an ash plume rose 1 km and drifted S and ejected incandescent tephra fell onto the flanks at a distance of 800 m from the crater. The Alert Level remained at Yellow, Phase Two (middle level on a three-colour scale).

Reventador | Ecuador : IG reported that during 17-24 March seismic data from Reventador’s network indicated a high level of seismic activity, including explosions, long-period earthquakes, and signals indicating emissions. Gas-and-ash emissions were observed almost daily, though cloudy weather often prevented views of the volcano; IG and the Washington VAAC reported gas-and-ash emissions rising around 500-900 m above the crater rim, and as high as 2 km, and drifting NE, SE, S, and W. Ashfall was reported in San Rafael (8 km ESE) on 17 March. Incandescent blocks rolled 900 m down the S and SE flanks during 23-24 March.

Santa Maria | Guatemala : INSIVUMEH reported that explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose 500-900 m above the crater and drifted as far as 1 km NW, W, and SW. Avalanches of blocks descended the SE, E, S, and SW flanks of Caliente cone.

Semisopochnoi | United States : AVO reported that activity at Semisopochnoi had decreased compared to the previous week. Seismicity remained elevated during 19-24 March and no surface activity was observed on most days, though weather clouds often prevented visual confirmation. A steam plume was visible in a satellite image on 21 March and weakly elevated surface temperatures were identified in one satellite image during 21-22 March. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Shishaldin | Fox Islands (USA) : AVO reported that seismicity at Shishaldin was characterized as near-continuous tremor during 18-20 March and continuous tremor during 21-24 March. Steam-and-gas plumes rising from the summit crater were recorded daily by the webcam and sometimes identified in satellite images. Elevated surface temperatures, consistent with lava in the summit crater, were also identified in satellite images. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that during 13-19 March incandescence from Suwanosejima’s Ontake Crater was visible nightly. On 14 March an ash plume rose 400 m above the crater rim. On 23 March the Tokyo VAAC reported that an explosion produced an ash plume that rose to an altitude of 0.9 km (3,000 ft) a.s.l., or 120 m above the summit, and drifted SE. The Alert Level remained at 2 (on a 5-level scale).

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