Volcanos

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

Aira – Kyushu (Japan) : JMA reported that during 16-23 November incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. One explosion and two eruptive events produced plumes that rose 1.4-1.6 km above the crater rim. The daily sulfur dioxide emission rate was high at 2,000 tons per day on 18 November. The Alert Level remained at 3 (on a 5-level scale).

Copahue – Central Chile-Argentina border :SERNAGEOMIN reported that during 1-15 November activity at Copahue decreased to low levels. Passive gas emissions generally rose 200-300 m above the vent, though on 15 November they rose 760 m. The report also noted no changes to deformation, low levels of sulfur dioxide emissions, low seismicity, partial restoration of the crater lake, and the absence of nighttime crater incandescence since late October. The Alert Level was lowered to Green (the lowest level on a four-colour scale) on 15 November. ONEMI cancelled the Yellow Alert for the Alto Biobío municipality, but declared a “Preventive Early Warning” ensuring continued surveillance of the area and coordination within the Civil Protection System.

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 18-24 November ash plumes from Dukono rose to 1.8-2.1 km (6,000-7,000 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 explosions during 13 and 15-17 November that sent ash plumes up to 3.5 km (11,500 ft) a.s.l. and drifted NE, E, and SE. Ashfall was reported in Severo-Kurilsk during 16-17 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu – Halmahera (Indonesia) : PVMBG and the Darwin VAAC reported that on 19 and 22 November ash plumes from Ibu were identified in satellite images rising to 2.1 km (7,000 ft) a.s.l. and drifting SW and W. 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 and wind model data, the Darwin VAAC reported that on 18 November ash plumes from Kadovar rose to an altitude of 0.9 km (3,000 ft) a.s.l. and drifted W and NW.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 15 and 19 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that Strombolian activity at Klyuchevskoy continued during 13-20 November and lava advanced down the Apakhonchich drainage on the SE flank. A large, bright thermal anomaly was identified daily in satellite images. During 16-18 November explosions recorded in satellite and video data produced ash plumes that rose as high as 7.5 km (24,600 ft) a.s.l. and drifted 104 km E, SE, and S. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale) on 8 October.

Reventador – Ecuador : IG reported that a high level of activity continued to be recorded at Reventador during 17-24 November. Seismicity was characterized by explosions, volcano-tectonic and harmonic tremor events, and long-period earthquakes as well as signals indicating emissions. Gas, steam, and ash plumes, observed sometimes multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 1.3 km above the summit crater and drifted mainly NW, W, and SW. Crater incandescence and incandescent blocks rolling 600 m down the NE and S flanks were observed during 17-21 and 23-24 November. The 450-m-long lava flow on the NE flank remained active but did not advance.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 17-24 November. Seismicity was characterized by explosions, harmonic tremor, long-period earthquakes, and signals indicating emissions. Weather clouds sometimes prevented visual observations of the volcano, but the Washington VAAC and IG webcams recorded daily ash plumes that rose 900-2,100 m above the summit and drifted mainly W and SW.

Santa Maria – Guatemala : INSIVUMEH reported that explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose 1.1 km above the complex and caused ashfall in areas SW and E, based on El Observatorio Vulcanológico del Complejo Volcánico Santa María-Santiaguito (OVSAN) observations. Weak pyroclastic flows descended the W flank of Caliente cone.

Semeru – Eastern Java (Indonesia) : PVMBG reported that the eruption at Semeru continued during 17-24 November, though weather conditions sometimes prevented visual confirmation. Dense white-to-gray plumes rose up to 300 m above the summit. Crater incandescence was visible at night during 19-20 November and 11 incandescent avalanches traveled 500-1,500 m down the Kembar and Kobokan drainages on the S flank. Two eruptive events produced gray ash plumes that rose 100-200 m above the summit and drifted SW during 23-24 November. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 1 km and extensions to 4 km in the SSE sector.

Semisopochnoi – United States : AVO reported that no signs of eruptive activity at Semisopochnoi had been recorded since mid-June. Seismicity had been elevated above background levels but declined to very low levels before 11 November, when the satellite the link to transmit the data failed. Both the Aviation colour Code and the Volcano Alert Level were lowered to Unassigned, reflecting the lack of available seismic data to detect unrest.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 13-20 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that at 1344 on 18 November an eruptive event at Sinabung generated an ash plume that rose 1 km above the crater rim and drifted SW. At 2137 on 21 November seismic data indicated an emission, though weather conditions prevented visual confirmation. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported nighttime incandescence and intermittent eruptive activity at Suwanosejima’s Ontake Crater during 13-20 November. A total of 18 explosions were recorded, ejecting bombs as far as 400 m from the crater and producing gray-and-white plumes that rose 1.5 km above the crater rim. Ashfall was reported in Toshima village (4 km SSW) on 13 November. The Alert Level remained at 2 (on a 5-level scale).

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