Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 29 December 2021 – 4 January 2022

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 27 December 2021 to 3 January 2022. An eruptive event at 2324 on 28 December produced an ash plume that rose 1.1 km above the crater rim. An eruptive event at 2105 on 1 January 2022 generated ash plumes that rose 1 km and ejected bombs 600-900 m away from the crater.

Davidof – United States : AVO lowered the Volcano Alert Level for Davidof to Unassigned on 31 December, noting that the earthquake swarm that had begun in early December had subsided. The closest seismometers are approximately 15 km E, on Little Sitkin Island. Davidof is also monitored by satellite data and remote infrasound and lightning networks.

Fukutoku-Oka-no-Ba – Volcano Islands (Japan) : The Japan Coast Guard reported that during a 27 December overflight of Fukutoku-Oka-no-Ba, observers noted that the island formed in mid-August had become smaller since 14 December, and had almost eroded below the ocean surface. No eruptive activity was observed, though brownish water spouted from the E end of the island. Yellowish-green water and a string of floating pumice, 400 m long, was circulating 5 km E. Discolored water was visible around almost the entire coast of Minami-Ioto (5 km SSW).

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 29 December 2021 to 4 January 2022 along with very low and persistent seismicity. Satellite images acquired on 29 December 2021 and 1 January 2022 showed that the lava flows on the W flanks had advanced.

Ibu – Halmahera (Indonesia) : PVMBG reported that during 31 December 2021 to 4 January 2022 gray-and-white ash plumes from Ibu rose 200-1,000 m above the summit. Avalanches were detected daily, though not visually observed.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 28-30 December.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava effusion intermittently continued from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 29 December 2021 to 4 January 2022. Effusion at the vent paused on the evening of 29 December and the lake mostly crusted over, though lava oozed over the edge of the lake margins in several areas, suggesting a continuing supply of molten lava below the crust. Parts of the crusted lake overturned during 2000-2300. Occasional minor activity at the vent was visible during the morning of 30 December, and lava again began effusing form the vent at 1445. Several large lava overflows of the lake occurred in the evening and bright glow was visible in the evening sky from Volcano to lower Puna. Lava effusion was low during 1-2 January and by 0200 on 2 January the lake once again began to crust over. A large breakout along the N margin of the lake was active. Effusion ceased during 2-4 January; the lake was mostly crusted over except a few overturns N of the vent were noted.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 31 December 2021 to 4 January 2022. White-and-gray ash plumes that were sometimes dense rose as high as 600 m above the summit. Incandescent material was occasionally ejected from the vent up to 300 m from the vent and rumbling was sometimes heard.

Merapi – Central Java (Indonesia) : BPPTKG reported no notable morphological changes to Merapi’s summit lava dome, though the dome just below the SW rim had decreased about 3 m in height during 24-30 December. The estimated dome volumes were over 1.63 million cubic meters for the SW dome and just over 3 million cubic meters for the summit dome. The intensity of the seismic signals remained at high levels. As many as 175 lava avalanches traveled a maximum of 2 km SW down the Bebeng drainage, and two pyroclastic flows traveled a maximum of 1.8 km SW.

Nevado del Ruiz – Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 28 December 2021 to 3 January 2022 seismicity at Nevado del Ruiz was at similar levels to the week before, characterized by periods of continuous volcanic tremor, long-period events, and very-long-period earthquakes, indicating movement of fluids. These earthquakes occurred in the vicinity of Arenas Crater. Additional earthquake signals indicating rock fracturing were located in the SW, SE, and NE parts of the volcano. Several periods of “drumbeat” seismicity, indicting growth of the lava dome, were recorded during 29-30 December and 3 January. Several low-level thermal anomalies were identified in satellite images during the week. The highest gas-and-steam plume rose about 1.2 km above the summit, recorded on 3 January.

Pavlof – United States : AVO reported that seismicity at Pavlof was elevated during 29 December 2021 to 4 January 2022 and was characterized by daily periods of tremor. Minor ash emissions were visible during 28-29 December and small explosions were occasionally recorded during 29-30 December. Thermal emissions continued to be low, and elevated surface temperatures consistent with a hot vent region were identified in satellite images during 1-3 January. During 3-4 January lava was active in an area within 100 m of the SE vent.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that at 1437 on 1 January a small eruption at Rincón de la Vieja produced a plume that rose 50 m above the crater rim. A small eruption was recorded by the seismic network at 0431 on 4 January, though weather clouds prevented visual confirmation. The amplitude of the seismic signal was similar to those recorded for events occurring in the previous few weeks.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 32 explosions at Sabancaya during 27 December 2021 to 2 January 2022. Gas-and-ash plumes rose as high as 2.8 km above the summit and drifted NW, W, and SW. Eight thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N).

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity and elevated seismicity at Semisopochnoi’s North Cerberus crater continued during 29 December 2021 to 4 January 2022. Minor ash-and-steam emissions were visible in webcam images during 28-29 December. Ash plumes observed in webcam and satellite images on 31 December rose to 1.5 km (5,000 ft) a.s.l. and drifted as far as 100 km NE. Ash emissions observed in webcam images during daylight hours on 1 and 2 January were being blown down the flank by high winds. Small explosions were detected in seismic data during 2-4 January, though cloud cover obscured views.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 24-31 December. Intense steam-and-gas emissions were visible. Ash plumes rose as high as 4.5 km (14,800 ft) a.s.l. and drifted 110 km NW and NE during 24-25, 27, and 30 December.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that crater incandescence at Suwanosejima’s Ontake Crater was visible nightly during 27 December 2021 to 3 January 2022. The number of explosions totaled 124. The explosions produced ash plumes that rose as high as 2.2 km above the crater rim and ejected material up to 1.1 km distance from the crater.

Yasur – Vanuatu : On 30 December the Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a high level of “major unrest,” as defined by the Alert Level 2 status. Activity consisted of loud explosions, emissions of steam and ash, and the ejection of bombs that fell inside and around the crater area.

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