Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 17 March 2021 – 23 March 2021

Aira – Kyushu (Japan) : JMA reported that during 15-22 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion on 15 March produced an eruption plume that rose 1.5 km above the crater rim and ejected bombs 500-700 m away from the crater. The explosions on 20 March generated plumes that rose as high as 1.6 km. The sulfur dioxide emission rate was 1,800 tons per day on 12 March. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 16-23 March ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 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 explosions during 12-15 and 18-19 March that sent ash plumes to 2.6 km (8,500 ft) a.s.l. and drifted E, NE, and NW. Ashfall was reported in Severo-Kurilsk on 12 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea – Hawaiian Islands (USA) : HVO reported that two vents on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 17-23 March. Lava flowed from both the main vent and a vent several meters NE into the lake through submerged inlets. Another lava flow emerged from about halfway up the cone structure starting at 0220 on 16 March, but had ended by the next day. The depth of the western part of the lake rose from about 221 m to 223 m and lava continued to circulate in that part. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. The sulfur dioxide emission rate was 650, 700, and 1,100 tons/day on 17, 18, and 19 March, respectively. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the Strombolian eruption from vents on Klyuchevskoy’s lower NW flank continued during 12-19 March. A large, bright thermal anomaly over the vents was identified in satellite images. Kamchatka Volcanological Station scientists visited the eruption site on 16 March and observed decreased activity. A small lava flow effused from a vent at the W base of the cone and lava flowed from the N side. Every few seconds material was ejected as high as 100 m above the cone’s rim. On 22 March the cinder cone was weakly incandescent and lava effusion continued to be observed in webcam images. The temperature of the thermal anomaly identified in satellite data also significantly decreased. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale) on 22 March. Two days later, on 24 March, the Aviation colour Code was lowered to Green (the lowest level); weak incandescence from the cone and flows visible in webcam images reflected cooling.

Laguna del Maule – Central Chile-Argentina border : SERNAGEOMIN reported that during 1-15 March the seismic network at Laguna del Maule recorded a total of 123 volcano-tectonic earthquakes. The largest event was a local M 2.4 located 8.2 km WSW of the lake, at a depth of 4.4 km. One tremor event was also recorded. Recent carbon dioxide emission measurements showed an upward trend and that the area of anomalous emissions had expanded. Deformation rates were higher than maximum averages. The Alert Level remained at Yellow, the second lowest level on a four-colour scale. ONEMI maintained a Yellow Alert for San Clemente and recommended restricted access within a radius of 2 km from the center of elevated carbon dioxide emissions.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 17-23 March. Daily gray-and-white ash plumes rose as high as 700 m above the summit and drifted mainly E and SE. Incandescent material was ejected 300 m E of the summit on 20 March. The next day incandescent material was ejected 100 m above the summit and as far as 200 m E. On 22 March explosions ejected incandescent material 250-350 m SE. The eruptive events were accompanied by rumbling and banging sounds. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summit crater.

Nevados de Chillan – Chile : SERNAGEOMIN reported that activity at Nevados de Chillán’s Nicanor Crater was ongoing with sporadic gas-and-ash emissions and continuing lava effusion during 1-15 March. Explosions produced eruption plumes that rose as high as 1.3 km above the crater rim, and sometimes ejected material as far as 160 m onto the NE flank. The L5 lava flow on the N flank was about 925 m long and 80 m wide at the distal end, and continued to slowly advance. The Alert Level remained at Yellow, the second lowest level on a four-colour scale. ONEMI stated that Alert Level Yellow (the middle level on a three-colour scale) remained in place for the communities of Pinto and Coihueco, noting that the public should stay at least 2 km away from the crater.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray-and-white ash plumes rose 300-900 m above Raung’s summit during 16-23 March. Ash plumes drifted mainly N, E, and S. 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.

Reventador – Ecuador : IG reported that a high level of activity continued to be recorded at Reventador during 16-23 March; adverse weather conditions sometimes prevented visual confirmation. Seismicity was characterized by 31-81 daily explosions, volcano-tectonic and harmonic tremor events, and long-period earthquakes as well as signals indicating emissions. Gas, steam, and ash plumes were often observed multiple times a day with the webcam or reported by the Washington VAAC; they rose as high as 1.5 km above the summit crater and drifted mainly NE, E, and SW. Crater incandescence and incandescent blocks rolling at least down the N, NE, and E flanks were observed nightly.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 17-23 March. Seismicity was characterized by daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds and rain often prevented visual observations of the volcano, though based on the Washington VAAC, webcam images, and observer reports, ash plumes were noted most days rising as high as 1.5 km above the summit and drifting mainly N, W, and SW. A seismic station recorded occasional debris flows during 17-19 March. No ashfall was reported by residents.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 12-19 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 16-23 March. Weather conditions often prevented visual observations of the volcano, particularly during the end of the week. Avalanches were detected daily by the seismic network and observed traveling 500-1,500 m down the E and SE flanks during 16-18 March. 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.

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to slowly grow during 17-23 March, expanding to the N and S. A team visited the dome on 19 and 23 March to make observations, take measurements, and maintain monitoring equipment. Gas-and-steam continued to rise from the top of the dome as well as along the contact between the old and new domes. As of 19 March the dome was 105 m tall, 912 m long, 243 m wide, and had an estimated volume of 13.13 million cubic meters. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the seismic network for Suwanosejima’s Ontake Crater detected a total of 11 explosions during 12-19 March. These events produced eruption plumes that rose as high as 1.7 km above the crater rim and ejected bombs up to 700 m away from the crater. Incandescence from the crater was occasionally visible at night. The Alert Level remained at 2 (on a 5-level scale).

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