Friday, 12 March 2021

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 3 March 2021 – 9 March 2021

Aira – Kyushu (Japan) : JMA reported that during 1-8 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion at 1810 on 1 March ejected bombs 600-900 m away from the crater; an eruption plume was not confirmed. That same day the sulfur dioxide emission rate was high, at 2,900 tons per day. An explosion on 5 March produced an eruption plume that rose 2.7 km above the summit and ejected bombs 800-1,100 m away. 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 7-9 March ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted E, SE, and SW. 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 26-28 February and 1-2 March that sent ash plumes to 3.6 km (11,800 ft) a.s.l. and drifted in multiple directions. Ashfall was reported in Severo-Kurilsk on 26 February and 2 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kikai – Japan : In response to an eruption at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim, on 2 November 2019 JMA had raised the Alert Level to 2 (on a 5-level scale). Since then, surveillance cameras sometimes recorded minor incandescence reflected in emitted plumes. On 8 March JMA revised the Alert Level guidelines, keeping the level at 2, but reducing the exclusion zone around the crater from 1 km to 500 m.

Kilauea – Hawaiian Islands (USA) : HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 2-8 March through a submerged inlet. The sulfur dioxide emission rate was 1,000 tons/day during 2-3 March, and 800 tons/day on 7 March. The depth of the western part of the lake fluctuated around 219-220 m. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. Rangefinder measurements and visual observations indicated that the eastern and western portions of the lake were rising at the same rate, suggesting that lava was accumulating under the crusted eastern portion. In recent weeks a part of the cone, several meters NE of the main vent, occasionally fed short (less than 100 m) lava flows that entered the lake at the crusted margins. During 5-7 March flows from this vent poured lava into the lake at several shifting inlets, though lava also accumulated on the lake margin within 50 m of the vent. By midday on 7 March the flows had built a perched lava pond on the NW lake margin, but it abruptly collapsed just after 1300. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 3-9 March; weather conditions sometimes hindered visual observations. Gray-and-white ash plumes rose 100-1,000 m above the summit and drifted E, SE, SW, and W. Incandescent material was ejected 300-800 m SE from the crater during 3-6 March. Rumbling and occasional thumping sounds were reported. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summer crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome just below Merapi’s SW rim and the new lava dome in the summit crater both continued to grow during 19-25 February. The 2021 lava-dome volume was an estimated 618,700 cubic meters on 25 February, with a growth rate of about 13,600 cubic meters per day. A total of three pyroclastic flows traveled 1.9 km down the SW flank. One of the three, recorded at 1652 on 25 February, was followed by minor ashfall in Kali Tengah Lor, Kali Tengah Kidul, Deles, and Tlukan. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km awa

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray ash plumes rose 200-1,200 m above Raung’s summit during 2-9 March. Ash plumes drifted mainly 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.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 3-9 March. Seismicity was characterized by daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds often prevented visual observations of the volcano, but satellite and webcam images recorded daily ash plumes. Ash plumes were notable during 5-6 March and impacted communities downwind with ashfall. According to the Washington VAAC ash plumes rose 5.8-12.2 km (19,000-40,000 ft) a.s.l. and drifted 170-370 km SW, W, and NW; ash at altitudes of 5.8-8.2 km (19,000-27,000 ft) a.s.l. drifted 185 km E. During 5-6 March ashfall was reported in Alfredo Baquerizo Moreno (132 km W), but fell more significantly in Alausí (61 km WSW), Chunchi (73 km SW), Cumandá (90 km WSW), Guamote (42 km WNW), Pallatanga (70 km W), Milagro (140 km W), San Jacinto de Yaguachi (150 km W), Samborondon (170 km W), Daule (180 km W), and Durán (168 km W). SNGRE reported that the ashfall affected a total of 108,457 people (23,750 families) as well as numerous crops and animals; they distributed volcano-related aid kits to impacted populations. Ashfall continued to impact multiple communities during 6-7 March. Ash fell in Guayaquil (175 km W), General Antonio Elizalde (97 km WSW), Simón Bolívar, Milagro (140 km W), San Jacinto de Yaguachi (150 km W), El Triunfo (125 km WSW), Daule, Samboróndon (170 km W), Coronel Marceliño Maridueña (120 km WSW), Durán, Naranjito, Alfredo Baquerizo Moreno, Playas (240 km WSW), Guamote (40 km WNW), Alausí (60 km SW), Pallatanga (70 km W), Chunchí (72 km SW), and Colta (55 km NW).

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 26 February-5 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

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 2-8 March. The SE part of the dome was in line with the pre-existing fumarolic area on the 1979 dome. Gas plumes continued to damage vegetation in the summit area as well as on the SW flank. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported intermittent eruptive events at Suwanosejima’s Ontake Crater during 26 February-2 March. Bombs were ejected as far as 600 m away from the crater and ashfall was reported in Toshima village (4 km SSW). The number of explosions began increasing on 2 March; the total recorded through 1500 on 7 March was 139, but by 1500 on 8 March there was only one additional explosion. The Tokyo VAAC reported that ash plumes rose 0.9-2.1 km (3,000-7,000 ft) a.s.l. during 3-7 March. An explosion at 0317 on 6 March ejected tephra as high as 500 m above the crater rim and bombs 900 m away. The Alert Level remained at 2 (on a 5-level scale).



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